Chillies- good and bad for your health

There are is a growing body of research into the effects of chillies on our health- both good and bad.

There are is a growing body of research into the effects of chillies on our health- both good and bad.
The potential for both health and harm has always been a defining characteristic of chilli peppers, and among scientists, doctors and nutritionists it remains a matter of some dispute.

A new study, published in the British Medical Journal, seemed to indicate that a diet filled with spices – including chillies – was beneficial for health.

A team at the Chinese Academy of Medical Sciences tracked the health of nearly half a million participants in China for several years. They found that participants who said they ate spicy food once or twice a week had a mortality rate 10% lower than those who ate spicy food less than once a week. Risk of death reduced still further for hot-heads who ate spicy food six or seven days a week.

Chilli peppers were the most commonly used spice among the sample, and those who ate fresh chilli had a lower risk of death from cancer, coronary heart disease and diabetes.

While the health-promoting properties of chillies may not be fully understood, at least we have a good idea where to look to find the source of them. Cut a chilli open and you will see yellow placenta-like fronds that attach the seeds to the inside of the fruit. In most types of chilli, this is the location of the spice’s secret weapon – capsaicin.

It is capsaicin that makes chillies hot. The heat is measured in Scoville heat units, which is the number of times a sample of dissolved dried chilli must be diluted by its own weight in sugar water before it loses its heat. For a green bell pepper this is zero. But habanero peppers have a Scoville value of between 100,000 and 350,000. For pure capsaicin the figure is 16 million.

While the Satanic-red horns of chillies seem to hint at their throat-scorching potential, extracted capsaicin is an odourless and colourless substance.

More importantly for humans, chillies also evolved to repel microbes. Chillies kill or inhibit 75% of such pathogens.

It is sometimes said that people in hot countries use more chilli because it makes them sweat, which cools them down. But in 1998, researchers at Cornell University pointed out that the greater use of spices in countries such as India, Thailand and China was likely to be linked to their anti-microbial function.

This correlation with climate, and the attendant risk of infectious disease, was greater than the link with the right growing conditions for the spices. In other words, humans in dangerous climates developed a taste for chilli which probably saved them a lot of death.

We now know that chillies are also a good source of antioxidants. Forty two grams of the spice would account for your recommended daily allowance of vitamin C. They are also rich in vitamin A, as well as minerals such as iron and potassium.

Capsaicin has even been touted as a potential weight-loss tool. Research conducted this year by the University of Wyoming on mice that had been fed a high-fat diet found that the molecule increased metabolic activity in the animals, causing them to burn more energy and preventing weight gain. In another study, published last month in Plos One, researchers at the University of Adelaide found that the receptors in the stomach that interact with capsaicin play a role in sensing when we are full. Previous studies on humans seem to back the idea that eating spicy food seems to curb our appetite.

The recent study in China found a correlation between the consumption of spicy food and lower rates of death from those diseases – and laboratory research from the last 10 years suggests some possible reasons for that too.

In 2012, a team of nutritionists at the Chinese University of Hong Kong, working with hamsters, found that capsaicin helped break down so-called “bad” cholesterol which might have clogged up the animals’ arteries, but it left alone the “good” cholesterol which helps remove it. There was a second benefit for cardiac health too – the capsaicin appeared to block the action of a gene that makes arteries contract, restricting blood flow.

Several studies have also indicated that capsaicin has powerful anti-cancer properties. It has been found to be helpful in fighting human prostate and lung cancer cells in mice, and there are also indications that it could be used as a treatment for colon cancer. It may also improve drug resistance for bile-duct cancer sufferers.

“There are a lot of reports that say that capsaicin may be good for human health, especially with cancer,” says Zigang Dong at the Hormel Institute of the University of Minnesota. “However, there are other reports that show totally the opposite result.”

Dong is the co-author of a 2011 review, published in the journal Cancer Research, titled The Two Faces of Capsaicin, in which claims about the spice’s benefits for health are laid alongside a long list of counter-claims, pointing to negative effects.

The report details six studies on rats and mice in which the animals developed signs of cancer in the stomach or liver after their diet was changed to include more capsaicin. Meanwhile, studies examining the effects of capsaicin on the human stomach have delivered wildly divergent results. While one showed visible gastric bleeding after consumption of red pepper, another showed no abnormalities, even when ground jalapeno peppers were placed directly in the stomach.

“Probably it is harmful in the stomach or oesophagus because capsaicin itself can cause inflammation,” says Dong. “And if anything can cause inflammation or so-called burning effect, it must cause some cell deaths and therefore the long-term chronic inflammation is maybe harmful.”

Capsaicin – and the chilli pepper – remains enigmatic. But whether it is a friend or foe, we’re exposing ourselves to it more and more. Between 1991 and 2011, global consumption of dry chillies increased by 2.5% per year, while our per capita intake increased by 130% in that time.

But after being over-stimulated the neurons stop responding, killing the pain. This process involves the release of endorphins, which can give us a “rush” not dissimilar from the feeling of having exercised well. This may explain why some people believe that hot food is addictive.

Healthy lives may prevent dementia

The number of people living with dementia is levelling off- possibly due to healthy lives.

The number of people living with dementia is levelling off- possibly due to healthy lives.The University of Cambridge study shows the proportion of elderly people with the condition in the UK has fallen, contrary to predictions that cases would soar.

Improvements in health and levels of education might be protecting people from the disease, the scientists said.

The report, in the Lancet medical journal, analysed twinned dementia studies that were conducted in the same way, but decades apart.

Data from five studies from the Netherlands, UK, Spain and Sweden showed that the proportion of people with the condition had stabilised over the periods covered by the studies – which ranged from nearly 20 years to almost 30. But in the UK and among Spanish men, it had fallen.

In the UK, the data from 1991 suggested that 8% of over-65s would have dementia in 2011, yet the team in Cambridge said the figure was in fact 6%.

It means there are around 670,000 over-65s with the condition rather than the 810,000 figure regularly cited.

An ageing population should have led to more people living with dementia. However, lead researcher Prof Carol Brayne said the expected rise “had not occurred”.

“Effectively it has stabilised rather than gone up. The age-specific prevalence has gone down so even though the population has got older, the number of patients with dementia has stayed the same.”

She said the findings suggested there may be a “preventable component within individuals, and across whole populations”.

“It may be possible that we can defer dementia rather than prevent it entirely – it’s very unlikely that we can prevent it entirely.”

The exact reason why rates have fallen is uncertain, but improvements to the health of nations are the most likely. Risk factors for dementia include:

vascular disease
little exercise

However, it said there was a “new and emerging” picture showing that dementia might not be increasing as rapidly as previously thought.

It said the condition was already a huge social and economic problem, with a quarter of hospital beds filled with dementia patients.

Meanwhile, Dr Matthew Norton, from Alzheimer’s Research UK, said the findings were encouraging, but the risk factors for dementia were “not yet fully understood”.

He also warned: “Current trends in risk factors such as obesity and diabetes mean we should not be complacent. But measures to help people adopt healthy lifestyles now could have a real impact on the numbers of people living with dementia in the future.”

Sweating in the gym may not lose weight

Exercise is the world’s best drug- it’s just not a weight loss drug.

Exercise is the world’s best drug- it’s just not a weight loss drug.A friend complained recently about not losing her winter paunch this summer despite swimming almost daily at the beach, combined with aerobic and weight workouts at the gym. When I pointed to the double scoop of ice cream she was happily devouring, she replied that she thought she had earned a reward for all her physical efforts.

My friend was operating under a fanciful illusion which is promoted by the fitness centre industry and glossy magazines: if you work out regularly, preferably with an expensive trainer or the magazine’s special exercises, you will lose weight and attain the body of your dreams.

But there is no scientific support for this notion. In fact, the evidence is quite the opposite. “You can’t outrun your fork,” says Yoni Freedhoff, an assistant professor of medicine at the University of Ottawa and founder of Canada’s Bariatric Medical Institute, which advises patients on non-surgical weight management.

“People tend to eat back their exercise,” Dr Freedhoff says. He notes there is an “unfair balance” between calorie consumption and calorie burning. It takes only a couple of minutes to gulp down a KitKat but the chocolate bar’s calories require more than an hour of heavy, sweaty exercise to burn off.

In fact, in one frequently cited study reported in the Journal of the American Medical Association, a group of 467 obese women was divided into four groups and put on an exercise regime with different levels of intensity; at the end of six months, none of the four groups had lost any weight.

One reason for this problem may be what is known scientifically as “hedonic compensation”, or rewarding yourself for doing something that you find unpleasant.

Carolina Werle, an assistant professor of marketing at the École de Management in Grenoble, France, recently conducted three fascinating experiments to see why people fail to lose weight with exercise.

For example, one group of people was told to engage in a fun walk while another group was given the exact same programme but was told that it was a specific form of exercise. At the end of the programme, both groups were taken to an all-you-can-eat buffet lunch. The group that had been told to exercise loaded up on fattening side dishes and pudding while the fun group ate less.

“The lesson is that the more fun we have while exercising, the less we will feel the need to compensate for it by eating more fattening food,” Ms Werle says. “It was just the perception of the activity that was different.”

Another myth, Dr Freedhoff says, is that more exercise will result in greater weight loss. Studies show that people who exercise for more than the recommended 150 minutes a week do not lose more weight than those who exercise less. They continue to gain weight, just at a slower pace, he says.

No one is suggesting that people abandon exercise programmes simply because they are not a good way to lose weight.

“The sad truth is there is nothing more beneficial to health than exercise,” Dr Freedhoff says. “When people don’t lose weight with this intervention, then they quit because the one thing they were told it was going to do, it doesn’t do.

“Exercise is the world’s best drug. It’s just not a weight loss drug.”

Fish diet could ward off depression

Eating a lot of fish may help protect against depression, research suggests.

Eating a lot of fish may help protect against depression, research suggests.An analysis of 26 studies of more than 150,000 people in total indicated a 17% reduction in the risk of depression among those eating the most fish.

One potential reason given by the researchers was the fatty acids found in fish may be important in various aspects of brain activity.

Mind, the mental health charity, said the study supported other work showing links between diet and mood.

Writing in the Journal of Epidemiology and Community Health, the Chinese researchers said many studies had been done looking at fish consumption and depression, but the results had been mixed.

When they looked at different study types, they found that the apparent protective effect of eating lots of fish was specific to studies done in Europe and not those from other areas of the world.

To try to come to a conclusion on what they said had been a controversial issue, they collated the data from all the relevant studies they could find conducted since 2001.

Their calculation did show a significant link between the two, and it was true for men and women.

While the results could not point to any conclusions about cause and effect, there were interesting theories as to why fish may be good for mental health, the researchers said.
Healthier diets link

One possible explanation is that the omega-three fatty acids found in fish may be key in the activity of dopamine and serotonin – two signalling chemicals in the brain thought to be involved in depression.

Another possibility is that people who eat a lot of fish may have a healthier diet in general – which in turn could help their mental health.

Prof Dongfeng Zhang, from the Medical College of Qingdao University, said: “Higher fish consumption may be beneficial in the primary prevention of depression.

“Future studies are needed to further investigate whether this association varies according to the type of fish.”

Rachel Boyd, information manager at Mind, said they had recently published a guide, Food and Mood, which included advice on eating the “good fats” such as those found in fish.

“It is important not to oversimplify the results as there are lots of different factors in the development of depression,” she said.

“But we really agree that having these fatty acids in your diet can be helpful, and it’s something where people can make quite small changes that could have quite a big impact.”

She pointed out that for vegetarians or others who did not want to eat fish there were other sources of fatty acids, such as seeds and nuts, as well as supplements.

Is your running style a problem?

Few forms of exercise are as natural as running- yet sometimes we may get into bad habits.

Few forms of exercise are as natural as running- yet sometimes we may get into bad habits. Young children manage to learn how to run without any special training and, as we enter adulthood, running remains an often unconscious activity.

However, for people who like to run as a sport, especially in middle age, nasty side effects such as pain in the knees, twinges down the side of the leg, and painful cramping in the foot can make you wonder whether you are running correctly.

The first person to publicly question our natural style of running was a British runner, Walter Goodall George, who trained as a chemist in the 19th century. Mr George invented a famous running exercise called the 100 Up, which many runners still use today. It had the virtue of training runners to land on the balls of their feet rather than their heels.

When jogging became a fashionable form of exercise in the 1970s, shoe manufacturers raced to provide cushioned shoes to help weekend athletes deal with the impact of pounding out miles on concrete roads.

But there is another way that might prove beneficial to runners who are still suffering agonies. Taking their cue from Mr George’s work, a number of sports scientists have looked at running to see if the method can be improved.

Christopher MacDougal, author of a book called Born to Run , has championed the running method used by Mexico’s Tarahumara Indians; another school follows a method loosely based on t’ai chi chuan, a form of Chinese martial arts, and yet another technique is called the Pose method, which was invented by a Russian track coach named Nicholas Romanov.

Although these styles employ different postures, they all state that heel striking, which most of us do when running, is bad for your body.

“Pain is a sign that you are doing something wrong,” says Mr Romanov, who now lives in Miami, Florida. “It means that you are deviating from nature’s way of doing things, which has evolved over millions of years.”

Mr Romanov, who has written a book, The Running Revolution: How to Run Faster, Farther, and Injury-Free – for Life, and holds running clinics in locations around the world, says that his Pose technique can reduce common injuries.

There are some scientific studies which back up the idea that by changing the way your foot strikes, you can reduce the impact forces on your knee joints. Of course, this force is now transferred from your knees to your ankle and foot, which Mr Romanov asserts are better equipped to absorb the shock.

The Pose technique is best learnt from a teacher, who can explain what each individual runner is doing wrong. In short, the Pose method not only has you landing on you forefoot, but also shortens your stride considerably from the days when you were heel striking. Romanov’s method uses gravity — you simply fall forward after landing — so there is no appreciable effort on the part of the runner.

Changing habits can be devilishly difficult because they are deeply ingrained. I was able to change my foot fall by running barefoot on a treadmill for several weeks before I even tried on the street. But if you suffer from aches and pains after running, as I did, learning a new technique could be the key to saving your knees.

Healthier lifestyles could cut cancer cases by a third

About a third of cancer cases in the UK could be prevented if people ate healthily, exercised more and cut down on alcohol according to new research.

About a third of cancer cases in the UK could be prevented if people ate healthily, exercised more and cut down on alcohol according to new research.Exercise is an important way of keeping fit and cutting body fat, which is linked to the risk of developing cancer

Data from the World Cancer Research Fund suggests that 20,000 cases of breast cancer and about 19,000 cases of bowel cancer could be stopped each year with small changes in lifestyle.

In 2013, there were more than 351,000 new cases of cancer in the UK. The WCRF said 84,000 could have been prevented.

Head of research Dr Rachel Thompson said simple changes to diet and lifestyle could make “a huge difference” in the battle against cancer.

“Even minor adjustments, like 10 to 15 extra minutes of physical activity each day, cutting down on alcohol, or limiting your intake of high calorie foods and sugary drinks, will help decrease your cancer risk,” she said.

She said that after cutting out smoking, being a healthy body weight was the most important thing people could do to cut their risk of getting cancer.

“There is strong evidence that being overweight or obese increases the risk of 10 cancers,” she said.

The link between a healthy lifestyle and the risk of developing cancer is well known, and this new data looks at preventable cases in 13 of the UK’s most common cancers.

For example, among men, 9% of cases of advanced prostate cancer could be prevented every year if men were not overweight or obese.

Lung cancer cases could be cut by 15,000 (33%) by getting people to stop smoking.

And 38% of breast cancer cases could be prevented, particularly in postmenopausal women, by increasing physical exercise and reducing body fat.

The WCRF also said that 2,200 cases of kidney cancer and 1,400 cases of pancreatic cancer could be prevented if people adopted a healthier lifestyle.

Prof Kevin Fenton, director of health and wellbeing at Public Health England, said the UK was currently behind on cancer survival rates compared with other European countries.

He said one major factor was that cancer prevention was not in the public consciousness.

“The link between tobacco and cancer is widely known and readily accepted by the public, but many are not yet fully convinced that healthy eating, regular exercise and not drinking alcohol, can lower your cancer risk.”

People aged 65 to 79 are happiest of all

Sixty five to 79 is the happiest age group for adults, according to Office for National Statistics research.

Sixty five to 79 is the happiest age group for adults, according to Office for National Statistics research.The survey of more than 300,000 adults across the UK found life satisfaction, happiness and feeling life was worthwhile all peaked in that age bracket, but declined in the over 80s.

Those aged 45 to 59 reported the lowest levels of life satisfaction, with men on average less satisfied than women. That age group also reported the highest levels of anxiety.

Researchers said one possible reason for the lower happiness and well-being scores among this age group might be the burden of having to care for children and elderly parents at the same time.

The struggle to balance work and family commitments might also be a factor, they said.

Meanwhile, those who were younger or retired had more free time to spend on activities which promoted their well being, the researchers suggested.

Happiness and well-being dropped off again in those over 80, however, with researchers suggesting this could be down to personal circumstances such as poor health, living alone and feelings of loneliness.

The survey asked people to rate out of 10 how happy and how anxious they had felt the day before, how satisfied they were with their life generally, and how much they felt what they did in life was worthwhile.

The published results have been broken down by age, ethnicity, religion, marital status, employment status, religion, and where in the country people live.

They suggested:

  • Married people had the highest levels of happiness, averaging 7.67 out of 10, higher than co-habiting, single, widowed or divorced people
  • People with jobs were happier than unemployed people, with part-time workers the happiest. Of those are were not working, retirees had the highest levels of happiness, followed by students
  • Of those who followed a religion, Hindus were marginally the happiest on average, followed by Christians and Sikhs, while those who followed no religion were the least happy
  • Women on average reported higher levels of anxiety than men, but were more likely report better well being and feel their life was worthwhile
  • People of Arab ethnicity were found to be the most anxious ethnic group, with people of Chinese ethnicity the least anxious
  • Northern Ireland held on to the crown for happiest of the UK’s nations, with people there also most satisfied and most likely to say their life was worthwhile – but also the most anxious; the least happy people were in England, with the North East the unhappiest region

Researchers found a strong link between health and well-being.

People who said their health was very good reported an average life satisfaction rating of 8.01 out of 10, compared with people who said they were in very bad health, whose average rating was just 4.91.

Drinking water doesn’t prevent a hangover, study says

Downing glasses of water after a night of heavy drinking won’t improve your sore head the next day- new Dutch research suggests.

Downing glasses of water after a night of heavy drinking won't improve your sore head the next day- new Dutch research suggests.Instead, a study unfortunately concluded- the only way to prevent a hangover is to drink less alcohol.

More than 800 students were asked how they tried to relieve hangover symptoms, but neither food nor water was found to have any positive effect.

A team of international researchers from the Netherlands and Canada surveyed students’ drinking habits to find out whether hangovers could be eased or if some people were immune to them.

Among 826 Dutch students, 54% ate food after drinking alcohol, including fatty food and heavy breakfasts, in the hope of staving off a hangover.

With the same aim, more than two thirds drank water while drinking alcohol and more than half drank water before going to bed.

Although these groups showed a slight improvement in how they felt compared with those who hadn’t drunk water, there was no real difference in the severity of their hangovers.

Previous research suggests that about 25% of drinkers claim never to get hangovers.

So the researchers questioned 789 Canadian students about their drinking in the previous month and the hangovers they experienced, finding that those who didn’t get a hangover simply consumed “too little alcohol to develop a hangover in the first place”.

Of those students who drank heavily, with an estimated blood alcohol concentration of more than 0.2%, almost no-one was immune to hangovers.

According to lead author Dr Joris Verster, from Utrecht University, the relationship was pretty straightforward.

“The more you drink, the more likely you are to get a hangover.

“Drinking water may help against thirst and a dry mouth, but it will not take away the misery, the headache and the nausea.”

Dr Verster said part of the problem was that scientists still do not know what causes a hangover.

“Research has concluded that it’s not simply dehydration – we know the immune system is involved, but before we know what causes it, it’s very unlikely we’ll find an effective cure.”

He said the next step was to carry out more controlled trials on hangovers.

Dr Michael Bloomfield, from University College, London, said the economic costs of alcohol abuse ran into hundreds of billions of euros every year.

“It’s therefore very important to answer simple questions like, ‘How do you avoid a hangover?’

“Whilst further research is needed, this new research tells us that the answer is simple – drink less.”

The paper is presented at the European College of Neuropsychopharmacology conference in Amsterdam.

Cycling to work without a helmet? Please think again

With more people cycling to work in cities such as London, New York, and San Francisco, the conversation often turns to the dangers of riding in heavy city traffic.

With more people cycling to work in cities such as London, New York, and San Francisco, the conversation often turns to the dangers of riding in heavy city traffic. I had an interview recently with a lawyer in London who began by apologising for being out of breath. “My wife banned me from riding my bike after three accidents in central London in the space of 12 months,” he explained. “I’ve gotten out of shape.”

I mentioned that I had just walked from Hackney in east London to the City and was surprised at the number of cyclists in the latest reflective and polypropylene cycling gear who were nonetheless weaving in and out of traffic without a helmet.

My lawyer friend laughed knowingly. “I keep a photo on my phone of my cracked helmet to show people what their head might look like when they cycle without one,” he said.

Boris Johnson, the mayor of London, has often sung the praises of cycling to work, and the rental bicycles scattered through the city are even nicknamed “Boris bikes” because of his support for them. But even though Mr Johnson has had a few close calls while cycling, he has refrained from making bicycle helmets mandatory.

I understand that riding in hot weather with a helmet can be uncomfortable, but I think the case for helmets, mandatory or not, is hard to dispute. Australia, New Zealand and parts of Canada have adopted compulsory helmet laws and it is clear that cycling deaths declined in the years after those laws were adopted.

Some have pointed out that the number of heart attacks rose in Australia because some cyclists gave up riding to work rather than wear a helmet, but is that really relevant?

The grim fact is that London had already reached eight cycling deaths by June of this year and New York recorded a doubling of fatalities from nine to 18 in 2014. It is true that the number of cyclists is increasing in both cities, which is a good thing, but that does not diminish the avoidable dangers. The victims included a prominent Manhattan surgeon and a neuroscientist, who were not wearing helmets.

Michael Carter, a paediatric neurosurgeon in Bristol, told me recently that he often sees cases of head injuries from bicycle accidents in his hospital’s emergency room that could have been avoided if the cyclists had worn helmets.

“It makes no sense whatsoever to ride without a helmet,” said Dr Carter, who has stopped cycling in the city because of the recent deaths of two friends.

The Cochrane Library, widely accepted as the gold standard for medical research worldwide, looked at bicycle accidents and did a statistical comparison of different studies to see if there were patterns in helmet use.

The review said that three quarters of all fatalities on bicycles result from head injuries. It found that “wearing a helmet reduced the risk of head or brain injury by approximately two thirds or more, regardless of whether the crash involved a motor vehicle.”

One solution to the problem of bicycle safety is the creation of dedicated bike lanes, which has happened in Berlin, New York and other cities and should be tried elsewhere. But they do not eliminate the danger entirely and the reasonable response is to wear a helmet, even for short rides.

If the above doesn’t convince you to wear a helmet- also consider that medical insurance payouts are halved if the cyclist wasn’t wearing a helmet.


Combine fasting and a cardio workout to shed weight quicker

What is the best way to lose weight? This question is particularly relevant when we tend to abandon good dietary habits on holiday and overindulge.

What is the best way to lose weight? This question is particularly relevant when we tend to abandon good dietary habits on holiday and overindulge.Much has been written about the effectiveness of the so-called 5:2 diet, which was popularised by a BBC television programme and involves restricting calories by 75 per cent on two non-consecutive days and then eating normally for the rest of the week.

Another way of implementing this kind of diet, which is known as intermittent fasting, or IF, is to cut back to 500 calories or eliminate food entirely on alternate days.

Intermittent dieting has been well studied and offers all the benefits of eating less, while reducing the problem of sticking with a reduced-calorie intake on a daily basis. After all, you get to eat normally most days. But there is a way to boost the health benefits of this kind of diet and supercharge your weight loss by adding cardio exercise to the mix.

A team of researchers at the University of Illinois divided obese volunteers into four groups: one group practised alternate-day fasting; a second group practised endurance exercise three days a week; a third group did both IF and exercise for 12 weeks; and the fourth control group did none.

The results were pretty striking: the combined exercise and IF group lost an average of 6kg, compared with 3kg weight loss for the IF-only group and just 1kg for the exercise group.

Interestingly, not only did the diet-and-exercise combination produce more weight loss, but it also helped the subjects’ blood lipid profiles, which are an indicator of heart attack risk. In the group that did both endurance exercise and restricted calories, so-called “bad” LDL cholesterol decreased 12 per cent from the baseline, while the “good” HDL cholesterol increased by an impressive 18 per cent. The other interventions produced no HDL benefit.

What is interesting about this and similar studies is that there has been a growing consensus that diet is much more important than exercise in maintaining good weight. But it is now clear that the two in combination are much more effective than either approach alone.

In addition, the endurance training in this study, which was performed on exercise bikes and elliptical machines in a gym, lasted 25 minutes and was at just 60 per cent of maximum heart rate, growing incrementally to 75 per cent of the maximum at the end of the study.

Surabhi Bhutani, the postdoctoral researcher who led the study, says this is because the subjects were obese and the researchers wanted to avoid the risk of cardiac problems.

But there is quite a lot of evidence that high-intensity interval training, or HIIT, involving short bursts of exercise at close to the maximum heart rate, followed by recovery periods, or slightly longer bursts of cardio exercise at 90 per cent of maximum heart rate, is more effective than slow endurance training. And it has the added benefit of taking less time.