Short bursts of intense exercise 'as good' as endurance training

Thursday April 28 2016

Sprint interval training is increasingly popular

"Researchers have found that short bursts of intense exercise produce similar results to traditional longer-duration workouts," the Mail Online reports.

Researchers compared two types of exercise programme over a 12-week period with a control. The two programmes were:

• a 10-minute "intense" workout, three times a week (referred to as Sprint Interval Training)
• a 50-minute moderate intensity workout, once a week

At the end of the study, they found similar improvements in reliable fitness markers in both groups, such as the body's response to insulin, peak uptake of oxygen and the functioning of muscle cells. However, it is uncertain that the changes seen would have an effect on cardiovascular disease risk and outcomes in the long term.

The study was also quite small (just 25 young men), and the results ideally need verifying in a larger trial, including a study of wider population groups, such as women and different age groups. The study showed no effect on the men's weight or body mass index (BMI), and did not include information about any adverse effects or risks.

The message that your health may benefit from a 10-minute workout is welcome for anyone who struggles to find time to exercise. However, the researchers warn that very high-intensity exercise is not suitable for everyone.

There are also questions over its safety. Famously, in 2013, the broadcaster and journalist Andrew Marr blamed high-intensity training for triggering his stroke.

If you think you are very unfit, it is probably best to build up your fitness gradually, rather than trying to go all-out straight away.

Where did the story come from?

The study was carried out by researchers from McMaster University in Canada and was funded by the Natural Sciences and Engineering Research Council and McMaster University.

The study was published in the peer-reviewed journal Public Library of Science (PLOS) One on an open access basis, so it is free to read online.

The Mail Online's headline that you only need a "minute of exercise" is a bit disingenuous, as the intervals of high-intensity exercise were within a 10-minute session, which included a warm-up and warm-down, and was done three times a week. However, the full text of the story quickly makes that clear, and reports the study reasonably accurately.

What kind of research was this?

This was a randomised controlled trial (RCT), which is a good way of finding out if a treatment works. Researchers wanted to know whether very short, high-intensity exercise could improve health measures as much as moderate-intensity exercise, when compared to a group who did a "no exercise" programme.

What did the research involve?

Researchers recruited 27 men (two later dropped out) who did little exercise and whose average age was 27. They matched them for similar age, BMI and peak oxygen uptake. They were then randomly assigned to either high-intensity sprint interval training (SIT), traditional moderate-intensity continuous training (MICT), or to a control group which was not given an exercise programme.

They carried out a number of tests on their cardiovascular and metabolic health at the start, during, then again after they finished the 12-week programme. They then compared results of the two exercise groups to the control group.

The tests included:

• peak oxygen uptake (VO2 peak), measured through a mask worn while cycling on an exercise bike – high oxygen uptake shows the heart and lungs are working efficiently
• insulin sensitivity index (CS1) measured by monitoring how quickly the body clears glucose from the blood, after it's been infused into a blood vessel – poor insulin sensitivity can lead to type 2 diabetes
• muscle mitochondrial content, measured by taking a muscle biopsy – mitchondiral content gives an indication of how efficient the muscle is at using energy

Both exercise programmes were carried out using exercise bikes and included a two-minute warm-up and three-minute cool-down, cycling at low intensity. For the SIT programme, men cycled three 20-second bursts of "all out" effort, separated by periods of two minutes of low-intensity cycling, adding up to 10 minutes in total. For the MICT programme, they cycled for 45 minutes at approximately 70% of maximal heart rate, adding up to 50 minutes total.

What were the basic results?

Both exercise groups improved on the three tests, while the control group did not show much difference on any test.

Maximum oxygen uptake improved by about 19% for both exercise groups. Insulin sensitivity improved by 53% for men in the SIT programme and 34% for men in the MICT programme, while the measure of mitochondrial content in muscle cells rose 48% after the SIT programme and 27% after MICT.

None of the men showed much change in their weight or BMI, although body fat percentage decreased for men on either exercise programme.

How did the researchers interpret the results?

The researchers said their study showed that a weekly exercise programme of 30 minutes, including three minutes of intense intermittent exercise, was as effective as 150 minutes a week of moderate-intensity, continuous training on three measures of cardiovascular and metabolic health.

"Considering that a large number of individuals do not meet the current physical activity recommendations, there is value in exploring the potential benefits of exercise strategies that involve reduced time commitment," they say. However, they warn that, "this type of exercise requires a very high level of motivation and is clearly not suited for everyone."

Conclusion

The idea that a 10-minute workout could have the same benefits as spending 45 minutes in the gym is tempting. The researchers found it may improve specific markers of health, in one group of young men.

However, this is a small study in a specific population, and we don't know whether it would have comparable effects in older people or women. Also, we don't know the long-term effects of this type of training programme on people's health.

Studies that look at the effects of an intervention, whether it's exercise, diet or medicine, on health measures such as insulin resistance and oxygen uptake, can only give us a short-term, partial picture. What we really want to know is whether an intervention will reduce your chances of having a heart attack or stroke, or of getting diabetes, or dying earlier. Unfortunately, that information can only come from very long-term studies, which are expensive.

One gap in the study is assessment of safety or negative effects of this type of exercise. High-intensity exercise has been linked in the media to the risk of stroke, especially after broadcaster Andrew Marr suffered a stroke shortly after completing an intense session of exercise.

This study doesn't report any adverse effects, nor does it address safety issues. It is probably too small and of too short a duration to be able to detect any. Ideally, some comparison of the risks of strokes or heart attacks with different types of exercise would be needed. However, this would require a large trial and with long enough duration to identify differences. 

There's no doubt that most of us need to do more exercise than we do, and that exercise has many health benefits. If you're concerned about the safety of a new exercise programme, it's best to talk to your doctor. You might need to start slowly and build up the amount and intensity of exercise you do, especially if you already have a medical condition. 

Government guidelines recommend that adults in the UK should do at least 150 minutes a week of moderate-intensity exercise, or 75 minutes of vigorous exercise, as well as exercise to strengthen muscles. Read more about health and fitness.

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Yoga 'probably good for asthma symptoms and quality of life'

Thursday April 28 2016

Yoga may help with breathing and stress

"Yoga could help asthma sufferers, research finds," reports The Independent.

A major review of existing data found there is "moderate-quality evidence" that yoga improves both symptoms and reported quality of life in people with asthma.

Yoga is an ancient form of exercise that focuses on strength, flexibility and breathing to boost physical and mental wellbeing.

Hong Kong-based researchers reviewed previously published data to see if yoga could improve symptoms and quality of life for people with asthma, compared with usual care or a dummy therapy.

Data from 1,048 people who took part in 15 randomised controlled trials (RCTs) was analysed. The researchers found small improvements for quality of life and symptoms, and a reduction in asthma medication use. However, the only meaningful clinical difference was for quality of life.

The review was well designed, but reviews are only as good as the studies they include – there was a high risk of bias in many studies.

There is also no comparison with other forms of exercise that could be equally effective in improving quality of life for people with asthma.

Still, one of the positives of yoga is that, provided you train with a properly qualified instructor, it is relatively risk-free and does not usually have any side effects or complications.

Read more advice about getting started with yoga. 

Where did the story come from?

The study was carried out by researchers from the Cochrane Collaboration and was funded by the National Institute for Health Research. 

It was published online via the Cochrane Library in the peer-reviewed Cochrane Databases of Systematic Reviews. The Cochrane Library is a non-profit organisation, so, like all their research, the review is open access and can be read for free online.

This story has been reported relatively accurately in the UK media, with a clear message that the findings are not entirely reliable because of the inclusion of flawed studies. We also don't know whether yoga has any negative effects, if any.

However, the Daily Mail's headline that yoga could help people with asthma "get their breath back" and reduce the risk of asthma attacks is rather misleading – this is not what this review concluded.

There was also some inaccuracy with The Independent's story, which incorrectly stated that participants were aged between six months and 23 years old – this was actually how long people had asthma for. We're not sure how you could get a six-month-old baby to start learning yoga.  

What kind of research was this?

This systematic review aimed to assess the effect of yoga in people with asthma.

A review like this combines data from individual studies to form conclusions about the current state of the evidence on the effectiveness and safety of an intervention.

Caution should always be taken with the results, however, as a systematic review is only as reliable as the studies included in the analysis. 

What did the research involve?

A comprehensive search of medical databases, trial registries, and hand-searching of relevant journals and meeting abstracts was carried out to identify studies for inclusion in the review.

The researchers decided to only include RCTs that compared yoga with usual care, no intervention, or a dummy intervention – a "sham" treatment.

They measured the following outcomes:

• quality of life
• asthma symptom score
• asthma control
• lung function measures
• asthma medication usage
• adverse events

After relevant studies were chosen, data was extracted on the characteristics of participants, interventions, methodology, and outcomes. Outcome data was combined where appropriate and analysed using statistical methods.  

What were the basic results?

Fifteen trials were included in the study, with a total of 1,048 participants. Participants mostly had mild to moderate asthma for a range of 6 months to more than 23 years.

The quality of the studies included was assessed as ranging from very low to moderate.

Analysis found some evidence that yoga may improve outcomes in people with asthma compared with usual care or a dummy intervention:

• quality of life – mean score difference on the seven-point scale of the Asthma Quality of Life Questionnaire (AQLQ) 0.57 units (95% confidence interval [CI] 0.37 to 0.77); 0.5 units is considered clinically meaningful
• improve symptoms – standardised mean difference 0.37, 95% CI 0.09 to 0.65; this is equivalent to a small effect
• reduce medication usage – relative risk 5.35, 95% CI 1.29 to 22.11; the wide range of this confidence interval casts the reliability of the result into doubt

To put these findings into context, the change in quality of life had a minimal clinically important difference, while yoga had no clinical benefit for symptoms.

Yoga did not improve lung function during the course of the study and there were no serious side effects associated with the practice, but there was limited data on this outcome.  

How did the researchers interpret the results?

The researchers concluded that, "We found moderate-quality evidence that yoga probably leads to small improvements in quality of life and symptoms in people with asthma.

"There is more uncertainty about potential adverse effects of yoga and its impact on lung function and medication usage.

"RCTs with a large sample size and high methodological and reporting quality are needed to confirm the effects of yoga for asthma."

Conclusion

This well-conducted systematic review aimed to assess whether yoga could improve outcomes for people with asthma when compared with usual care or dummy therapy.

Using statistical methods, small improvements were found for quality of life, symptoms, and a reduction in medication use.

However, the only effect that could make a meaningful difference for someone is the small benefit seen for quality of life.

The review itself was well designed. Efforts were made by the researchers to avoid combining studies that differed significantly in their design and methods.

However, this study did have some limitations:

• The studies included were of very low to moderate quality, and many were small in sample size, which has an impact on the reliability of the findings.
• The studies varied widely in their described yoga interventions and additional drug therapy.
• Some of the analyses included small numbers of participants and the confidence intervals were therefore wide, which reduces the reliability of the estimate.
• Data on some outcomes, such as unwanted side effects, was limited.
• Most of the studies included those with mild to moderate asthma, so yoga may not relieve symptoms in those that need it the most.

This review does not produce conclusive evidence that yoga would be beneficial to people with asthma, and any negative effects were not investigated.

The main thing it found was that yoga may improve quality of life – however, this could be the case if you take part in many types of physical activity, not just yoga. There was no comparison with other forms of exercise.

If you have asthma, there is usually no reason why you should have a restricted life. There are several things you can do to keep asthma under control:

• make sure to take all medicine as prescribed
• attend regular reviews
• understand your symptoms – know when to take your inhaler or call for emergency help
• keep away from known triggers, such as animal fur and cigarette smoke

Read more lifestyle advice about how to live better with asthma.

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Bedbugs 'prefer certain colours'

Tuesday April 26 2016

Bedbugs are attracted by your body heat

"Bed bugs appear to have a strong preference for particular colours," BBC News reports. A new study suggests the pests prefer red and black and "hate yellow and green".

It's unclear whether changing the colour of your bed sheets would prevent an infestation of bedbugs, though certain colours could prove useful for traps.

Bedbugs can be upsetting and cause a rash or itchy bumps on your skin. They don't pass on infectious diseases, but can cause an allergic reaction in some people, such as severe itching.

They can be present in even the cleanest of homes, but are more common in crowded lodgings and places with a high turnover of occupants.

Some tell-tale signs to look out for are blood spots on your sheets. Checking in the crevices of your mattress is a good way to spot them.

In this study, researchers used coloured tents in a petri dish and gave the bedbugs 10 minutes to choose their dwelling. Overall, bedbugs strongly preferred red and black, but tended to avoid colours such as green and yellow.

When they were split into sub-groups, the bedbugs' preferences varied by gender, whether they had recently been fed, and life stage.

However, this research can't tell us that yellow or green sheets would prevent an infestation of bedbugs.

If you do suspect bedbugs, it's recommended that you contact your local pest control firm, making sure they are a member of the British Pest Control Association, or your local council. 

Where did the story come from?

The study was carried out by researchers from Union College in Lincoln and the University of Florida.

Funding was provided by the Florida Pest Management Association and a University of Florida Endowed Professor Fund. Florida Pest Management Association is the trade group for the state's pest control companies.

The study was published in the peer-reviewed Journal of Medical Entomology on an open access basis, so you can read it for free online.

While the reporting of the study by the UK media is generally accurate, some of the coverage is not representative of the facts.

Neither the BBC's claim that bedbugs "hate yellow and green" nor the Mail Online's advice that you should "buy yellow sheets and avoid red carpets" is supported by the evidence.

The Daily Telegraph wins the shameless clickbait award of the day for managing to shoehorn in four Fifty Shades of Grey references in its first two paragraphs.

Some of the media sources carry some interesting speculation from a number of the study's authors.

One of the co-authors, Dr Corraine McNeill, explained: "We originally thought the bedbugs might prefer red because blood is red and that's what they feed on."

Dr McNeill went on to suggest that, "The main reason we think they preferred red colours is because bedbug themselves appear red, so they go to these harbourages because they want to be with other bedbugs.

"The bugs appeared to dislike yellow and green shelters, possibly because these bright colours remind them of brightly lit areas that are less safe to hide in." 

What kind of research was this?

This experimental laboratory study aimed to find out if bedbugs have a preference for living in specific-coloured dwellings.

This study is able to identify themes by observing the bedbugs' movements and examining differences by gender, life stage and nutritional status.

However, it cannot prove why they made their choices or if they would do so outside of the laboratory environment.  

What did the research involve?

The researchers set up an experiment that used small tents made from different coloured card in a petri dish to test where bedbugs would prefer to dwell.

Tests were performed to see if there were differences resulting from gender or nutritional status – starved (not fed within a week) or fed (blood one to two days before).

In a two-colour test, the bedbugs were to choose between the following eight colour dwellings against the standard white tent:

• lilac
• violet
• blue
• green
• yellow
• orange
• red
• black

A single bedbug was placed in the middle of the petri dish arena and was given 10 minutes, after which time the colour of the dwelling the bedbug was found under was recorded.

The next experiment used seven coloured tents – as above, excluding yellow – in a semi-circular arrangement and the same test was performed.

Bedbugs were tested either individually or aggregated in groups of 10 at a time. Groups were either all males, all females, or a 1:1 ratio of males and females.

Researchers also used these seven colours to test whether female bedbugs prefer to lay their eggs in dwellings of specific colours. 

What were the basic results?

Researchers found the two-choice and seven-choice colour tests indicate that red (28.5%) and black (23.4%) dwellings were the prime choices for bedbugs, while yellow and green were not popular at all. The colours chosen changed according to gender, nutritional status, aggregation and life stage.

Female bedbugs preferred lilac and violet, compared with males, who preferred red and black. When the bedbugs were fed, they appeared to be drawn to the orange and violet dwellings.

Significantly more eggs were laid in red, blue, orange and black dwellings compared with green. Bedbugs at different stages of life also appear to show different colour preferences, which may be down to the development of their eyes.  

How did the researchers interpret the results?

The researchers concluded that, "This study has given further support for bedbug preferences that may indicate that a mechanism exists for colour discrimination in bedbugs.

"Our findings should be useful in bedbug trap design as an attempt to enhance trap captures." 

Conclusion

This experimental laboratory study of bedbugs aimed to see whether the pests showed a colour preference for their dwellings.

The study found, overall, bedbugs strongly preferred red and black, but tended to avoid colours such as green and yellow.

When split into sub-groups, preferences varied by gender, whether they had recently been fed, and their life stage.

It is not clear why the researchers did not test yellow in their seven-colour test, as it would have been interesting to see whether the two-colour findings were replicated.

While these findings are of some interest and have been widely covered in the media, even the researchers say we shouldn't rush out to buy yellow sheets.

The research was only conducted over a timescale of 10 minutes, so we do not know what would have happened over time – for example, whether bedbugs would be less likely to mate and produce viable eggs if they were only given a yellow environment, or conversely whether their numbers would greatly increase in a red or black environment.

What we do know is that they need human blood to survive, prefer places that are warm, and can be carried on clothing and linen, hence why they are more common in hostels and places with a high turnover of people.

Bedbugs are very difficult to spot and can squeeze into the smallest of spaces. They are not attracted to dirt, so are not an indication of an unclean home.

Signs to look out for include:

• an unexplained rash on the skin, or itchy bumps
• black spots of their dried faeces on your mattress
• mottled shells, which they may have shed
• blood spots on your sheets where they may have been squashed
• looking in the crevices of your mattress to see if you can spot them
• in some cases of a large infestation, there could be a unpleasant, musty scent in rooms

If you do suspect bed bugs, it's recommended that you contact your local pest control firm, making sure they are a member of the British Pest Control Association, or your local council.

To prevent a bedbug infestation, inspect your mattress regularly for common signs and take immediate action if necessary. Avoid buying second-hand mattresses and be wary of old beds you might be using in rented accommodation.

Keeping your bedroom tidy and removing clutter, especially from the floor and under your bed, reduces the amount of hiding places for bedbugs.

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'Transformational managers' may be bad for workplace health

Friday April 22 2016

Does your boss motivate you, or intimidate you?

"Managers who pressurise their staff to go that extra mile risk harming their employees' health," the Daily Mail reports.

New research suggests "transformational managers" – charismatic high achievers – may increase levels of sickness in the workforce.

Supporters of transformational management would say it combines individual charisma and the ability to motivate staff and stimulate employees with being able to gauge the strength and weaknesses of staff members on an individual basis.

A poster boy for transformational management would be the late Steve Jobs of Apple fame.

But playing devil's advocate, you could argue that some managers who try to adopt this style fail to get their approach right, and it's more intimidation than motivation.

Think of the fictional boss from hell, Miranda Priestly, as played by Meryl Streep in the film The Devil Wears Prada. 

Researchers followed Danish postal workers for three years. Those with line managers displaying a transformational leadership style had more sick days off work a year later – about four days more a year. The link was not seen in the subsequent year.

They report some staff members were coming into work even though they were ill – what's known as presenteeism. This could exacerbate health problems and lead to long-term problems with productivity.

So overall, this study shows that transformational leadership may have a dark side, but needs more investigation so we can better understand the link. A longer-term assessment of the effects of presenteeism would also be useful.  

Where did the story come from?

The study was carried out by researchers from the University of East Anglia in the UK and the Danish National Research Centre for the Working Environment. It was funded by the National Work Environment Research Fund.

The study was published in the peer-reviewed journal, Work and Stress.

The media coverage was generally accurate, although the reporting tended to skate over the complexity of the relationship over time and its link with presenteeism.

What kind of research was this?

This longitudinal study followed 155 Danish postal workers over three years to track their presenteeism and sickness levels, and how these work-related measures were impacted by having a line manager with a transformational leadership style.

Transformational leadership was defined as having four main dimensions:

1. idealised influence or charisma – the leader acts as a role model and takes the lead in displaying desirable behaviour

2. inspirational motivation – the leader outlines a clear vision and the way forward

3. intellectual stimulation – the leader encourages employees to make use of their skills and coaches them in making their own decisions

4. individualised consideration – the leader acknowledges individual differences, and adjusts behaviour according to the individual's needs and capabilities

Previous research has shown leaders play a significant role in the sickness absenteeism patterns of their employees, but the question of whether a transformational leadership style increases sick leave has not yet been answered.

The research team thought the added pressure of this leadership style might encourage employees to come to work while unwell, potentially prolonging their own illness and actually increasing the overall number of sick days on a long-term basis. They set out to test this hypothesis.

What did the research involve?

The study interviewed a group of postal workers three times over three years to find out their line managers' leadership style, the number of days they took off work sick, and presenteeism.

To assess sick leave, employees were asked to say how many days they'd taken off work because of personal illness in the last year.

Estimates of presenteeism came from asking employees the question: "In the past 12 months how many workdays have you gone to work even if you were sick?"

Absence and presenteeism levels at year one were used as the reference level, so changes in year two and three were relative to this starting point.

Transformational leadership style was assessed by the employees using the Global Transformational Leadership Scale, a seven-item leadership questionnaire at year one only.

Response rates to the surveys from the postal workers were high in each of the three years, not falling below 86%.

Many eligible people were excluded from the analysis because of missing data on absence or presenteeism, which is a potential problem.

However, the researchers analysed both the included and excluded groups and found them no different in terms of absence or presenteeism rates.

The final sample analysed was 155 workers from 22 teams. The average age was 42 years and most (60%) were men.  

What were the basic results?

The results showed a changing relationship between leadership style and employee sickness over time.

Transformational leadership in year one increased sickness in year two, but not year three.

Postal workers took an average of 11 days off in year one, which increased to 14 in year two (a statistically significant increase) before dropping back to eight days in year three (statistically no different from year one).

The researchers found presenteeism levels in year one modified the link between transformational leadership and sick leave in year three, but not year two. 

A closer look at this relationship in year three found those who reported an average of 14 days more presenteeism in a year than their co-workers were more likely to be negatively influenced by transformational leadership in terms of taking more days off sick.

Groups with less presenteeism were not affected in the same way.  

How did the researchers interpret the results?

The researchers said that, "A large body of literature has found positive relationships between transformational leadership and well-being cross-sectionally (Skakon et al 2010), but it would appear that over time transformational leadership may also have negative effects on employees.

"Our results suggest that transformational leadership behaviours may have an adverse effect on those employees who frequently show up for work while ill.

"The constant pressure from transformational leaders to perform 'above and beyond the call of duty' and the accentuated pressure from the work group may prevent followers from recovering from the pressures at work, and as a result lead to sickness absenteeism."

In terms of solutions, they suggest: "Transformational leadership training should comprise health-related dimensions of transformational leadership.

"For example, intellectual stimulation should focus not only on developing competencies and mastery in followers [employees], but also on building their resilience and coping skills.

"Leaders could also be trained in incorporating wellbeing and health into the vision, goals, and objectives they develop for work groups. As role models, transformational leaders should display healthy behaviours and encourage followers to look after their own health." 

Conclusion

This study shows that a popular leadership style called transformational leadership may increase employee sick days, but this depends on employees' existing tendencies to show up to work when they're ill.

Those who tended to show up to work ill the most were also those most likely to be off sick more when a transformational leader was installed.

The researchers' theory was that those more likely to come into work when they're ill don't have a chance to recover from work and illness fully, leading to more sickness in the long term.

However, this study has a number of limitations to be aware of. Those reporting high levels of presenteeism may have been trying to appear to be good workers who would soldier on and go into work despite being unwell, which could skew the results.

Similarly, postal work – which is somewhat outdoorsy and active – is probably not a good model for most jobs in the UK, many of which are office based. This means the conclusions of this study can't be stretched to apply to all workers and settings. 

Also, sick leave was self-reported by employees, who were asked to recall the number of days they had off because of illness over the past year.

The employees' absence records would have been a more accurate source of days off work, but would not have been restricted to sick leave – also including absence because of a family emergency, for example.

The researchers appeared to have both sets of information available, and said that self-reported sick leave did correlate with employer records of total days off work as you'd expect, although only weakly.

Comparing the effects of leadership between self-reported sick leave and general absence would have given us a better idea of how much this measurement difference affects the end results.

The study was not able to tell us anything about how transformational leadership may exhibit adversely affect health. The hypothesis that this leadership style may prevent employees recovering from illness because of work pressures, leading to more sickness absenteeism, wasn't tested, so remains speculative.

Also, the estimate of transformational leadership style may not have been entirely accurate, as it was based on quite a short questionnaire. Error in this measurement would muddy the link the researchers were trying to assess, and could explain some of the lack of effect found in the short term.

Overall, this study shows that transformational leadership may have a dark side, but needs more investigation to better understand the link.

Some pressure at work can be motivating, but can eventually lead to work-related stress when it becomes excessive. This in turn can lead to symptoms of depression and anxiety.

Whatever the source of your stress, speak to your manager or someone else in your organisation who you feel comfortable talking to.

Read more about coping with workplace stress.

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Warning issued over alarming rise in 'super-gonorrhoea' cases

Monday April 18 2016

Gonorrhoea is caused by bacteria called Neisseria gonorrhoeae

"Doctors have expressed 'huge concern' that super-gonorrhoea has spread widely across England," BBC News reports.

Public Health England issued the warning about the rise of a strain of gonorrhoea that has developed resistance to a widely used antibiotic. 

What is gonorrhoea?

Gonorrhoea is a sexually transmitted infection (STI) caused by bacteria called Neisseria gonorrhoeae or gonococcus. It used to be known as "the clap".

The bacteria are mainly found in discharge from the penis and vaginal fluid.

It is easily passed between people through:

• unprotected vaginal, oral or anal sex
• sharing vibrators or other sex toys that haven't been washed or covered with a new condom each time they're used

Typical symptoms of gonorrhoea include a thick green or yellow discharge from the vagina or penis, pain when urinating, and bleeding between periods in women.

However, around 1 in 10 infected men and almost half of infected women don't experience any symptoms.

The infection can also be passed from a pregnant woman to her baby. If you're pregnant and may have gonorrhoea, it's important to get tested and treated before your baby is born. Without treatment, gonorrhoea can cause permanent blindness in a newborn baby. 

What is 'super-gonorrhoea'?

Super-gonorrhoea is a term used to describe strains of gonorrhoea that have developed a resistance against the antibiotic normally used to treat the infection – azithromycin. There is an alternative antibiotic called ceftriaxone, which is also effective.

But there are concerns that strains could also develop resistance to ceftriaxone, which would make the disease extremely challenging to treat.

Dr Gwenda Hughes, consultant scientist and head of the STI section at Public Health England, explained: "We know that the bacterium that causes gonorrhoea can rapidly develop resistance to other antibiotics that are used for treatment, so we cannot afford to be complacent.

"If strains of gonorrhoea emerge that are resistant to both azithromycin and ceftriaxone, treatment options would be limited as there is currently no new antibiotic available to treat the infection." 

What's the scale of the problem?

An outbreak of cases was first reported in Leeds in November 2014.

Additional cases have now been confirmed in the West Midlands and the south of England, five of which were in London.

This takes the total number of cases confirmed in England from November 2014 to April 2016 up to 34.

Cases have been reported both in heterosexual couples and men who have sex with men. 

How do I reduce my risk?

Dr Hughes advises that, "Everyone can significantly reduce their risk by using condoms with all new and casual partners."

Getting tested for STIs regularly can lead to early identification and treatment, as often these infections have no symptoms.

In addition, reducing the number of sexual partners you have and avoiding overlapping sexual relationships can reduce the risk of becoming infected.

If you have put yourself at risk of any STI, it is always best to seek advice from your local sexual health clinic.

Find sexual health services in your local area.  

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Would you trust a smartphone app as a contraceptive?

Thursday April 14 2016

Don't want to get pregnant? There (might) be an app for that

"An innovative new app might provide a more effective form of birth control than the contraceptive pill," The Sun reports.

The Natural Cycles fertility app combines the use of a thermometer to measure body temperature with calendar calculating methods – often referred to as the rhythm method – to work out the days when a woman would be at high or low risk of pregnancy.

More than 4,000 women were included in this Swedish study looking at how effective the app is at preventing pregnancy.

A total of 143 unplanned pregnancies occurred during the study period, 10 of which were the result of the app falsely indicating a safe day.

Data collected by the app was used to work out that, if used exactly as advised, 5 women out of every 1,000 will accidentally become pregnant, and 7 out of every 100 women will become pregnant for "typical use" (not using the app correctly), each year.

This app may be attractive for women who are unwilling to use other forms of contraception, possibly for religious or cultural reasons, or because they have concerns about the side effects of hormonal contraception.

This app may also help indicate the best days to try to conceive.

But an obvious disadvantage of this contraceptive method is that the app does not protect against sexually transmitted infections in the same way as a condom.

Further research weighing an app like this against established contraceptive methods would be required to confirm whether its effectiveness is comparable. 

Where did the story come from?

The study was carried out by researchers from the manufacturer of the application, Natural Cycles Nordic AB, along with the Karolinska Institutet and University Hospital, Stockholm.

Funding was provided by Natural Cycles Nordic AB.

There is a conflict of interest with this study, as the lead authors, Elina Scherwitzl and Raoul Scherwitzl, created the app and founded the company with stock ownership, while another author, Jonas Sellberg is employed by Natural Cycles Nordic AB.

The study was published in the peer-reviewed European Journal of Contraception and Reproductive Health Care.

It has been reported on accurately in the media, with statistical comparisons made between the effectiveness of the app and the effectiveness of the contraceptive pill.

The Daily Telegraph quoted the app's creators, who said: "The algorithm behind the app learns about each individual woman's temperature fluctuations over time, so becomes more accurate as you use it more frequently."

They went on to say: "You say what your goal is when you start the app, so if you are planning a pregnancy rather than preventing, we identify the most fertile days and flag if you need to see a fertility specialist."

What kind of research was this?

This was a retrospective data analysis study that aimed to evaluate the effectiveness of a fertility awareness-based method, supported by a mobile-based application, to prevent unwanted pregnancies as a method of natural birth control.

Retrospective studies are flawed in that the data collected was not intended for such analyses and may not always give an accurate representation.

What did the research involve?

The researchers included data from fertile women aged 18 to 45 who were using a mobile-based application, Natural Cycles, as a contraceptive method. Subscription to the service, including a thermometer, cost €50.

Women included in the analysis had to meet certain criteria. They had to have:

• accessed the app for at least three months during the study
• entered data for a total of at least 20 days
• not planned a pregnancy during the study period

At the beginning of the study women filled out a questionnaire related to their cycle, previous contraceptive use, height and weight. An additional optional questionnaire was sent via email three weeks before the end of the study.

Women entered their date of menstruation and body temperature recordings into the app until the end of the study, or until they dropped out because they were pregnant or had stopped using the method.

The data entered was then processed by the app to compute red (unsafe) or green (safe) days to indicate the risk of getting pregnant. The app considered the different phases of a woman's cycle and the associated changes in body temperature when computing risk.

Evaluation of the app as a contraceptive method was determined by the number of pregnancies identified from a positive pregnancy test result being entered, the algorithm detecting a pregnancy, or the online questionnaire.

All users considered potentially pregnant by the algorithm were classified as pregnant in this study, even if they failed to confirm with a pregnancy test, as requested by the app, to provide the most conservative estimates. 

Cases were considered unknown if it was not possible to detect a pregnancy with any of these methods. If a green day had been given within the fertile phase of a cycle where a woman had become pregnant, this was considered a failure.

Data collected was used to work out a Pearl Index, a measure of contraceptive effectiveness. A high Pearl Index means there is a high chance of unintentionally getting pregnant, while a low value means there is a low chance.

What were the basic results?

A total of 4,054 women tested the app, and 483,221 daily entries were analysed. The drop-out rate before the end of the study was high, at 1,397 women (34%).

The number of identified unplanned pregnancies was 143. Of these, 123 were positive test entries into the app, while 15 were detected with the algorithm and 5 were found through the survey.

Ten of the pregnancies were because the app falsely attributed a safe day within the fertile window. This indicates that if used correctly all the time, the application has a Pearl Index of 0.5, meaning 5 women out of every 1,000 will accidentally become pregnant each year.

For "typical use" – where the app is not used correctly – the Pearl Index was 7, which means that 7 out of every 100 women will experience accidental pregnancies each year.

The most conservative estimate, attributing a pregnant outcome to all 61 women for whom the pregnancy outcome was not known, gave a Pearl Index of 9.8 – 10 women out of every 100 each year.

Half of the pregnant women (51%) had logged unprotected sex during the fertile phase.

How did the researchers interpret the results?

The researchers concluded: "The application appears to improve the effectiveness of fertility awareness-based methods and can be used to prevent pregnancies if couples consistently protect themselves on fertile days."

Conclusion

This was a retrospective data analysis study that aimed to evaluate the effectiveness of a mobile-based app to prevent unwanted pregnancies as a method of natural birth control.

The app used data entered by the women to work out days when there was a high or low risk of becoming pregnant in the absence of hormonal or barrier contraception. 

The app was calculated to have a Pearl Index of 0.5, meaning 5 women out of every 1,000 will accidentally become pregnant each year. The Pearl Index was 7 for typical use, which means 7 out of every 100 women will experience accidental pregnancies each year.

Natural methods of contraception are popular for those who do want to use other methods of contraception. An app like this helps to keep track of which days are risky and when it would be better to abstain from unprotected sex.

But this study does have limitations. The retrospective design means data was not collected to specifically answer this question and may not be fit for purpose.

Most of the women in the study were aged 20 to 35, and therefore the findings may not apply to other age groups. 

The participants in this study purchased membership and were obviously keen to try this method. Their usage may not be a true indication of the effectiveness of this type of app if it was available for free.

Even here, where the app was purchased, a third of the women stopped using it, which is a much higher drop-out rate than other methods, such as the contraceptive pill. Reasons for stopping using the app were not provided in the study write-up.

In addition to helping women to avoid becoming pregnant, this app might also help indicate the best days to try to conceive. The authors mention that these days are underestimated by the app, but it may still help, provided women remember to enter details correctly.

A head-to-head randomised trial comparing such an app with established contraceptive methods would be required to establish how effective it is as a method of birth control, and would also be a better design to find out whether an app can replace the pill, as the headlines have stated.

However effective an application may be, it will not protect you against sexually transmitted infections, unlike the low-tech – but very reliable – condom.

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from NHS Choices: Behind the headlines http://ift.tt/1RYLLaB

'Exercise labels' should be added to food packets, expert argues

Thursday April 7 2016

Around half of people find the current labelling system confusing

"Food and drinks should carry labels showing how long it would take to walk or run off the calories, a leading health expert suggests," the Daily Mail reports.

In an opinion piece in the British Medical Journal, Shirley Cramer, chief executive of the Royal Society for Public Health, argues that the current "traffic light" food labelling system is not promoting positive changes in public health.

Cramer makes the case that "activity equivalent" labelling could change people's behaviour. 

Traffic light labelling

The widely used "traffic light" food labelling system is based on concepts most of us learn very early on in our childhood: green means "good", amber means "OK", and red means "bad".

Traffic light information is provided on an item's fat content, saturated fat content, sugar content, and carbohydrate content. In short, the more green on the label, the healthier the choice.

However, a 2015 poll carried out by Populus found 41% of UK adults found current front-of-pack information confusing.

As Cramer points out, "Such information needs to be as simple as possible so that the public can easily decide what to buy and consume in the average six seconds people spend looking at food before buying." 

Activity equivalent labelling

The idea behind activity equivalent labelling is that a series of easily recognisable icons would be used to represent types of physical activities, such as brisk walking (walking fast enough to get you slightly out of breath), running, cycling, and swimming.

The icons would be combined with a number representing the number of minutes you would need to spend doing that activity to burn off the calories in the food or drink item.

Examples helpfully provided by the Daily Mail include:

• an apple (93 calories) – this would take 21 minutes of brisk walking or 13 minutes of running to burn off
• a can of Coca-Cola (139 calories) – this would take 32 minutes of brisk walking or 20 minutes of running to burn off
• a 48g Snickers bar (245 calories) – this would take 56 minutes of brisk walking or 35 minutes of running to burn off
• a 50g bowl of cornflakes served with semi-skimmed milk (263 calories) – this would take an hour of brisk walking to burn off 

Cramer makes an intriguing case that such a scheme would offer the public a carrot rather than a stick: "The public is used to being told to avoid particular drinks and to cut down on specific foods. By contrast, activity labelling encourages people to start something, rather than calling for them to stop." 

Could the scheme be introduced?

Currently, legislation regarding the mandatory labelling of food and drink is decided at the European level.

Even if there was a political will and the food and drink industry was on board, it would probably take several years for such a scheme to come into place. And that is a very big if.

There is the possibility that some forward-thinking manufacturers might adopt the scheme on a voluntary basis. If the scheme proves popular with the public, it could also boost their sales and so be a possible win-win.

Our Understanding calories page has a calorie checker widget that allows you to check the calories of more than 100,000 different products.   

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Effects of vitamin D for heart failure far from 'stunning'

Wednesday April 6 2016

Vitamin D helps to regulate the amount of calcium in the body

"Vitamin D can produce 'amazing' improvements in heart function," claims The Independent about the results of a recent study, while BBC News reported suggestions the results were "stunning".

However, the study in question, which involved giving people with heart failure vitamin D supplements, did not result in better exercise capability.

Heart failure is caused by the heart failing to pump enough blood around the body at the right pressure. Your heart doesn't stop, but fails to work properly, causing symptoms of breathlessness, tiredness and ankle swelling.

Many people with the condition are also vitamin D deficient, prompting Leeds-based researchers to study whether vitamin D supplements might help the condition.

The study involved 229 participants who were randomised to receive either a daily high-dose vitamin D supplement for a year or a placebo.

People in the vitamin D group showed encouraging improvements in measures of left ventricular function, a gauge of how well blood is pumped from the heart with each heartbeat.  

But the study was unable to show any vitamin D-related improvements in the main symptoms of heart failure, and showed no improvement in walking distance.

Given that backdrop, it's a stretch to describe the hearts as "healed" – or call the results "stunning". Still, these are early days. Larger and longer-term studies may find out whether these heart changes improve the main symptoms of the condition over time.

Where did the story come from?

The study was carried out by researchers from the University of Leeds and Leeds Teaching Hospitals NHS Trust, and was funded by the Medical Research Council UK.

It was published in the peer-reviewed Journal of the American College of Cardiology.

Generally, the media reported the story accurately, though the implications of the research were arguably overhyped, possibly driven by the enthusiasm of the lead researcher in describing his team's work. 

The BBC did provide a more sober note of caution, however, quoting Professor Peter Weissberg of the British Heart Foundation, who cautioned: "the patients seemed no better at exercise.

"A much bigger study over a longer period of time is now needed to determine whether these changes in cardiac function can translate into fewer symptoms and longer lives for heart failure patients."  

What kind of research was this?

This was a double-blind randomised controlled trial (RCT) looking to see whether vitamin D3 supplements could help people with chronic heart failure.

People with heart failure are often older and can be vitamin D deficient, possibly the result of not getting enough sunlight, which stimulates vitamin D production in your skin.

The researchers wanted to see if boosting patients' vitamin D levels would help with the condition, which causes breathlessness, excess tiredness and swollen ankles.

An RCT is the best study design to find out whether vitamin D3 supplements improve chronic heart failure. The only way they can be improved is to make them larger or longer, or to pool the results of many RCTs investigating the same thing, called a meta-analysis. 

What did the research involve?

The research recruited 223 mostly male vitamin D-deficient adults with chronic heart failure caused by left ventricular systolic dysfunction – meaning the main pumping chamber of the heart on the left side wasn't working properly.

The researchers randomised half of the participants to take 100 micrograms of vitamin D3 supplements daily for a year, and half to take a placebo. The main measure of potential improvement was the distance the men could walk in six minutes.

A secondary measure was changes in their heart function, measured as the proportion of blood pumped from the heart – specifically, the left ventricle – on a heart scan, called the ejection fraction.

Changes in the size of the left ventricle were also monitored, although only 34 people had the two scans necessary to monitor change.

Neither the men nor those assessing their hearts or exercise for changes knew if they'd taken the placebo or vitamin D – a so-called double blind study.

The year-long study was completed by 163 people. The rest withdrew (23), died or deteriorated (28), or suffered side effects (5). 

What were the basic results?

Despite excitable headlines, the main measure of interest – the distance the participants could walk in six minutes – did not improve using vitamin D3. In fact, it was about 13 metres worse after a year.

Those in the placebo group actually walked an average of 10 metres more after a year. But the differences between placebo and vitamin D were small enough that effectively it meant they were no different from one another.

The finding that hit the headlines was a secondary measure of heart function, which improved more in people using vitamin D3 than those using a placebo, who also improved a little.

People using vitamin D improved their ejection fraction by 7.65%, from 25.6% to 33.25% over one year, while those on placebo improved by 1.36%, from 26.5% to 27.86%. Other significant changes were also seen for measures of how well the left ventricle was functioning.

No safety concerns or side effects seemed apparent in those using vitamin D3 supplements for the year.  

How did the researchers interpret the results?

The researchers concluded: "One year of 100 micrograms daily 25-OH vitamin D3 supplementation does not improve six-minute walk distance, but has beneficial effects on LV [left ventricular] structure and function in patients on contemporary optimal medical therapy. Further studies are necessary to determine whether these translate to improvements in outcomes."

They added: "New therapies for serious chronic conditions, including CHF [chronic heart failure], are often expensive, increasingly technical and frequently fail to meet the rigorous demands of large phase 3 clinical trials.

"Vitamin D might be a cheap and safe additional option for CHF patients and may have beneficial effects on multiple features of the syndrome."

Conclusion

This study showed that taking daily vitamin D3 supplements for a year did not improve the ability of people with chronic heart failure to walk further, but did improve elements of their heart function.

The study was well designed, but larger studies are needed to confirm the findings more definitively.

The main limitations of the research include the fact the main focus was on men, its relatively small size, and an absence of measures relating to the main symptoms of the condition.

The study was not able to tell us whether the heart change improvements seen enhanced quality of life in terms of breathlessness, tiredness and swollen ankles. There were no improvements seen in walking distance.

If you think you may be vitamin D deficient, talk to your doctor about whether supplements may help, or whether getting more sunlight may be an equally effective and more attractive approach.

If you take vitamin D supplements, do not take more than 25 micrograms (0.025mg) a day, as it could be harmful, though taking less than this is unlikely to cause any harm.

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from NHS Choices: Behind the headlines http://ift.tt/1Vx9Zdh

Choir singing may boost immunity in people affected by cancer

Tuesday April 5 2016

There is a body of evidence that singing can boost mood

"Being in a choir could help the body fight cancer by boosting the immune system," the Daily Mail reports. 

The study involved 193 people from Wales who were affected by cancer in some way. This included people with a history of cancer, carers for people with cancer, and bereaved people who had lost someone to the disease.

The researchers had them take part in a 70-minute choir rehearsal.

Findings showed a decrease in stress levels and improvement in mood after the singing session compared to before. Levels of immune and inflammatory proteins that boost the body's ability to fight serious illness were also found to increase.

There are a number of limitations to the study.

Participants were already part of a choir – so clearly already found enjoyment in group singing – and there was no control group. The study also only assessed a single session, so we don't know whether effects would be replicated at other sessions.

The majority of the study population was made up of older white Welsh women, so the results may not be applicable to other populations.

Also, changes in levels of immune proteins alone are no evidence that this will "beat cancer". A longer follow-up period would be required to assess this claim.

Still, the results do support the opinion that taking part in a physical group activity you enjoy – whether it is singing, dancing, or joining a walking group – may improve both physical and mental wellbeing.

Where did the story come from?

The study was carried out by researchers from the Royal College of Music, Imperial College London, University College London and Tenovus Cancer Care (a Welsh cancer charity). Funding for the study was provided by Tenovus Cancer Care.

The study was published in the peer-reviewed medical journal ecancermedicalscience on an open-access basis, so you can read it for free online.

While the study was generally reported accurately by the UK media, many of the headlines overstated the findings. For example, The Daily Telegraph's headline "Singing in choir could help beat cancer" is currently unsupported by the available evidence.

That said, the Telegraph did provide an insightful quote from Diane Raybouldone, of the study participants, who is reported as saying that, "Singing in the choir is about more than just enjoyment, it genuinely makes you feel better. The choir leaders play a huge part of course, but so does the support of the other choir members, the inspirational programme and uplifting songs."

The science news website EurekAlert contains a link to a short video produced by the research team.

What kind of research was this?

This was a preliminary single arm (non-comparative) trial investigating whether people affected by cancer can benefit from singing in a choir.

The two main aims of the study were to compare changes across time in three different groups of people affected by cancer (carers, bereaved people and patients) and to assess whether responses differed between groups, to see if singing could be more beneficial to some than others.

While the study has found a link, it cannot prove that singing is responsible for any outcomes measured – mostly because there's no control group to compare against. However, as this is described as a preliminary study, it seems that more research will follow.

What did the research involve?

The researchers recruited five choirs in South Wales to participate in the study. Members of the choir were invited to take part if they were either a current carer of someone with cancer, a bereaved carer, or someone with cancer themselves – though not currently undergoing any cancer treatment, such as chemotherapy or radiotherapy. 

To participate in the study, people had to have attended at least one choir session and be over the age of 18.

Participants were to take part in the 70-minute choir rehearsal, which consisted of warm-up exercises, learning new songs as a group and singing familiar songs.

In the week before the rehearsal session, participants answered demographic and psychological questions in the form of a self-administered questionnaire, including assessments of:

• wellbeing – using the Warwick-Edinburgh Mental Wellbeing Scale
• anxiety and depression – using the Hospital Anxiety and Depression Scale
• social function – using the Connor-Davidson Resilience Scale

Then, immediately before and after the rehearsal, visual analogue scales were filled in to assess mood and stress; this involved choosing a point on a line that runs from 0 (none) to 10 (extremely). Saliva samples were then taken for analysis of biological measures, such as levels of the stress hormone cortisol and cytokines, which are involved in the immune response.

What were the basic results?

There were 193 people in the study; the majority were white and female. Groups were split as below:

• carers (72)
• bereaved carers (66)
• people with cancer (55)

On average, participants did not have symptoms of depression and had average levels of wellbeing. The study found a decrease in levels of the stress hormone cortisol and an increase in cytokines after the singing session compared to before, across all five of the centres and among all three groups.

Mood was seen to significantly improve overall and stress levels were found to decrease. Mood particularly improved for those with a lower state of mental wellbeing beforehand, and stress appeared to decrease the most in those who were initially more anxious and had higher depression levels.

No significant differences were observed across groups for psychological or biological measures.

How did the researchers interpret the results?

The researchers conclude: "This study demonstrates associations between singing and reduced negative and increased positive effect, reduced cortisol, oxytocin and beta-endorphin and increased levels of cytokines. This is the first study to demonstrate the widespread immune effects of singing, in particular its effects on cytokines."

They go on to say: "However, it would be of interest to ascertain whether such changes could be sustained with repeated exposure to the intervention over a longer time-span and with more specific patient groups. Such research could identify whether the psychosocial benefits of a communal activity such as group singing could lead to enhanced immune function in patients and carers affected by cancer."

Conclusion

This was a preliminary trial to assess whether singing in a choir can have a beneficial effect on the health and wellbeing of people affected by cancer.

The study found a decrease in stress levels and improvement in mood across all study groups after the single singing session, compared with before. The levels of immune and inflammatory proteins that boost the body's ability to fight serious illness were also found to increase.

This study, however, has some important limitations, many of which have been stated by the authors.

One is that it sampled a small population of mainly white women – who were already part of a choir, and therefore presumably already found enjoyment from singing. This reduces the generalisability to other groups. 

The study was uncontrolled, with no comparison group. It is possible that some of the results may have been seen even in the absence of singing; for example, if they had used the 70 minutes just to relax.

Participants in the study were a self-selected group who had low stress levels at the start of the study. Therefore, the same effect may not be seen in those who have higher stress levels.

The assessments were made only before and after a single singing session. We don’t know whether the same results would be replicated on repeat singing sessions, or for how long the effects would be sustained.

We also don't know whether any observed effects could be the result, not of singing itself, but of socialising and being together with other people in a group. It would be interesting to see whether the same results would be seen if an individual sang alone in their house, for example.

Despite the optimistic media headlines – changes in levels of immune proteins alone are no evidence that singing could "beat cancer".

Dr Ian Lewis of Tenovus Cancer Care said these are exciting findings: "We have been building a body of evidence over the past six years to show that singing in a choir can have a range of social, emotional and psychological benefits, and now we can see it has biological effects too."

It is too early to say whether these early findings have any solid foundation and many questions remain unanswered. More research will be needed to confirm these early findings. However, there is no harm in getting together with others and enjoying some singing, whether you have been affected by cancer or not.

A quick trawl of your favourite search engine should find a range of opportunities to take part in group activities, many of which are designed for older people who may be feeling isolated.

Read more about connecting with others when you are older. 

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from NHS Choices: Behind the headlines http://ift.tt/238uuTC

Global obesity rates expected to soar in next decade

Friday April 1 2016

Obesity continues to be a global health problem

"One-fifth of adults worldwide will be obese by 2025," The Guardian reports, while The Sun warns that the "UK's population to be fattest in Europe" by the same date. These are just some of the conclusions of a major modelling study of global obesity trends.

The study used data covering 19.2 million adults in 186 countries, which was then used to estimate the number of people falling into different body mass index (BMI) categories across the decades, from 1975 to 2014. During that time, the average global BMI for men and women rose by the equivalent of a weight gain of 1.5kg per person, per decade.

High-income English-speaking countries, including the UK, the US, Australia, Ireland and Canada, accounted for some of the biggest rises in BMI. These countries account for more than a quarter of severely obese people in the world.

Interestingly – if worryingly – parts of the world not normally associated with obesity, such as Central and South America, the Middle East and China, are also expected to develop high rates of obesity in the future.

In sharp contrast, the spectre of malnutrition doesn't seem to be going anywhere. Parts of Africa and south Asia still have high rates of people who are underweight: about a quarter of women living in south Asia are underweight. This trend is not expected to change.

The scientists who compiled the data warned that the chances of meeting the global target to halt the rise in obesity were "virtually zero".  

Where did the story come from?

The study was carried out by researchers from many different institutions, led by Imperial College London, and was funded by The Wellcome Trust and Grand Challenges Canada. 

It was published in the peer-reviewed journal The Lancet on an open-access basis, so it can be read online for free.

The UK media mainly focused on information not found in the published study but included in a press release sent out by The Lancet.

This information gave estimations of what the UK's obesity rates might be in 2025, compared with other European countries, presumably based on trends in the data. However, we don't know how these calculations were made, so we can't tell how accurate they are.

Only BBC News and The Independent picked up on the sobering fact that we may end up in a world where a majority of the population are obese, while others continue to go hungry.

An honourable mention has to go to The Sun's headline writers, who gave us "Lard of Hope 'n Glory – UK's population to be fattest in Europe by 2025". 

What kind of research was this?

This was an analysis of measurement studies done in countries around the world between 1975 and 2014.

The data from the studies was pooled to give a global picture of how the weight profile of the global population has changed.

What did the research involve?

The researchers looked for population-based studies that measured people's height, weight, gender and age, then combined them to give the best estimate of BMI ranges for 200 countries and 21 regions in each year.

They used estimates to fill in data for countries where there had been no or insufficient studies. They looked at the way BMI categories had changed over time for different countries, and calculated the chances of each country meeting the global target to halt the rise in obesity.

The analysis included 1,698 studies from 186 countries, covering more than 19 million people. Researchers restricted the studies to those where people had been measured by a researcher, rather than reporting on their own height and weight.

The researchers then used statistical techniques to test the validity of the estimates they made.  

What were the basic results?

Average body mass index rose globally from 1975 to 2014 for men and women. However, it's more interesting to look at the data for individual regions or countries, as there is so much variation between regions.

In the UK, the average BMI for men rose from 24.1 in 1975 to 27.4 in 2014. For women, BMI went from 23.4 to 27. A BMI of 18.5 to 24.9 is considered ideal for an adult.

The rise for both sexes was about 1kg/m2 each decade, although that slowed to about 0.5kg/m2 from 2005-14. The UK has 6.8 million obese men – the eighth highest country in the world – and 7.7 million obese women – the eleventh highest country in the world.

China and the US now have the most obese people in the world, with the US having the most severely obese people of any country. China also comes second in the number of underweight men and women, after India.

The researchers say the trend of increasing obesity slowed among some countries after 2000, notably in countries with high incomes, perhaps as a result of increased concern about obesity. 

How did the researchers interpret the results?

The researchers concluded that no country has more than a 50% chance of halting the growth of obesity on current trends, and the UK's chances are between 0% and 25%. They said: "Some high-income and middle-income regions are now facing an epidemic of severe obesity."

They went on to say rising obesity levels have not yet shown an increase in earlier deaths, but this may be because of the availability of drugs to combat high blood pressure, high cholesterol and diabetes in richer countries.

The researchers said even these drugs "will not be able to fully address the hazards of such high BMI levels" in the future, warning that "bariatric surgery [weight loss surgery] might be the most effective intervention". 

Conclusion

The figures in the study make for startling reading. Although it's difficult to draw conclusions from a mass of data covering the whole world, it seems clear that adults are becoming progressively heavier, and high-income countries such as the US and UK now have a large proportion of adults who weigh more than is healthy.

The study relies on hundreds of different studies carried out by different organisations, so it is subject to any inaccuracies that might have happened during the measurement and recording process.

However, the researchers only chose studies that had independent measurements of weight and height, so the overall results should be more accurate than if they'd relied on self-reported measurements. 

It is now recognised that obesity can often start in childhood. The researchers noted that trends in childhood obesity were not studied here because of difficulties in standardising the measures.

Despite the lack of success in halting the rise in adults, preventative public health interventions for children and families may hold out more promise.

What is less clear is the impact of this global weight gain. As an accompanying editorial points out, global life expectancy has been rising at the same time as BMI, by over 10 years during the study period.

So are we getting "healthier but fatter", as the editorial suggests? We know obesity increases the chances of many life-threatening diseases, including diabetes, heart disease and some cancers. It may be, as the study authors suggest, that modern medicine has managed to keep up with rising obesity so far.

We shouldn't ignore the number of people who are still underweight in the world. While this is a small proportion of people in rich countries like the UK, more than 200 million people in India are underweight for their height.

China and India together account for more than half of the men and women who are underweight in the world. It is striking that China and India both also feature in the top 10 countries with obesity in men.

The release of the data has been accompanied by calls from health campaigners for the government to do more to tackle unhealthy eating and obesity.

Find out more about how to maintain a healthy weight.

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from NHS Choices: Behind the headlines http://ift.tt/1X3oYue