Posts tagged ‘Obesity’
New guidelines from the National Obesity Forum suggest using “harder hitting” anti-obesity campaigns, akin to anti-tobacco campaigns, in the UK. The debate about whether to treat obesity like smoking is one that has played out in the US, with researchers still searching for the most effective way to improve health outcomes.
As former smoker, Dan Gilmore realised the power of stark works and images in changing his behaviour.
“Somewhere along the line, people said, ‘Would you please go outside and smoke,’ or, ‘I’ve got an allergy to smoking.’ You started to feel societal pressure,” says Gilmore, president emeritus of the Hastings Institute, a centre devoted to bioethics and public policy.
The in-your-face smoking campaigns of the past, he says, effectively convinced people both that their actions bothered others and posed grave danger to themselves.
When it comes to obesity, he says, “the public has not as thoroughly been terrorised.”
But he’s yet to find the right balance of “light stigma” to help motivate people without alienating them.
Unlike some other areas of medicine, the goal of obesity treatment is not necessarily to get to a normal weight. It’s to move in a direction where your health is significantly improved”
Scott Kahan National Center for Weight and Wellness
Alienation is a big risk when it comes to anti-obesity campaigns. Research shows those initiatives that make people feel bad about themselves tend to backfire.
“Campaigns that focus primarily on body weight, or the number on the scale, or used hard-hitting controversial approaches to get attention were messages that tended to blame or stigmatise people for their weight,” says Rebecca Puhl, deputy director at the Rudd Center for Food Policy and Obesity at Yale University. “Those were not found to be effective,”
“People are more responsive to campaigns that address specific health behaviour that people can engage in regardless of their body type.”
Indeed, one ex-smoker and ex-dieter says there is already a level of stigma around weight.
“People wouldn’t openly sneer at me because I was a smoker, but they do that because I’m fat,” says Lesley Kinzel, senior editor at XOJane.com and author of Two Whole Cakes: How to Stop Dieting and Learn to Love Your Body.
And yet, she says, it’s more difficult to pinpoint those who may suffer from obesity-related illnesses than it is to identify smokers.
Ads like this, used in the UK, painted a stark picture of the consequences of smoking
“People want to associate certain behaviour with fatness, but in real life fat people exhibit a wide range of different behaviour in regards to their eating habits and physical activity. If you’re a smoker, it’s because you smoke cigarettes.”
The many complex factors surrounding obesity, and the fact that obesity itself is not a behaviour but a state of being, makes comparing the two types of campaigns difficult, says Scott Kahan, director of the National Center for Weight and Wellness.
At the same time, he says, there are lessons to be learned from anti-smoking campaigns.
“Sometimes people fall into the trap of looking back at the anti-tobacco effort and say, ‘What we did was shame people into not smoking, and did hard-hitting campaigns of not smoking,'” says Mr Kahan,
“But that’s not the central part of what we did with the tobacco epidemic.”
What proved successful in the US was a complex, multi-faceted approach, he says.
“Smoking was addressed from the top down and bottom up,” he says.
“On the one hand there was education.”
Some recommendations from the National Obesity Forum report
- “Harder-hitting campaigns similar to anti-smoking”
- “GPs should be encouraged to engage with patients on obesity and weight management issues”
- “Government initiatives should include greater focus on hydration in weight management and health outcomes”
- “Greater focus needs to be devoted to strategies supporting individuals who are already obese”
- “Greater promotion of physical activity outside of educational settings”
This came in the form of public awareness campaigns, the surgeon general’s report outlining the dangers of smoking, and increased educational initiatives in schools and the work place.
On the other, he says, were changes that created “supportive environments to make it easier to not start smoking or to stop smoking,” he says.
This included higher taxes on cigarettes, restrictions on how the products could be marketed and sold, and the creation of more smoke-free areas, such as in restaurants and bars.
Indeed, Kinzel stopped smoking when the expense and hassles of smoking began to mount. “At a certain point it became too inconvenient,” she says.
While the US has seen big drops in smoking rates, obesity numbers have not dropped significantly, and in many cases continue to climb.
That has American researchers focusing not on changing numbers on the scale, but on encouraging healthy behaviours.
“The outward appearance of obesity is a distracter and a red herring,” says Mr Kahan. “If you take someone who is significantly overweight and they work hard and do what they need to do and lose 10% of their body weight, more often than not they will see tremendous health and function improvements.
The best campaigns contain education and environmental changes that make healthy choices easier, say experts
“At the same time, they’re still really fat. We still point fingers of them losing weight, and that’s not really necessary.”
While the goal of anti-smoking campaigns was to stop people from smoking, campaigns devoted to obesity seek a less-tangible outcome.
“The goal of obesity treatment is not necessarily to get to a normal weight. It’s to move in a direction where your health is significantly improved.”
To that end, says Ms Puhl, campaigns should focus on behaviours to improve health, not body size.
Motivating people to eat better and move more has beneficial effects for everyone, she says, not just the obese.
Obesity is a global issue caused by a multitude of factors.
Experts agree that urgent action is needed and that everyone has a role to play in finding a solution.
But which single action stands to make the biggest impact?
Terry Jones, director at the Food and Drink Federation, says consumers need to brush up on their health knowledge and shop savvy.
“There is no simple or single solution to tackling obesity and we all need to play a role. For our part, manufacturers are changing product recipes, creating new healthier options, investing in consumer education and providing clear nutritional information to enable healthier choices.
“We must help people gain a realistic understanding of the foods and drink that they consume, and how they can fit into a healthy diet. Making greater use of nutrition labelling can help us all to manage our intake of calories and certain nutrients over the course of a day.
“We agree that more needs to be done to ensure that both adults and children take advantage of the opportunities to fit exercise into their everyday lives.”
Sabrina Bushe of the New Policy Institute says much of the problem boils down to poverty.
“Obesity is a general problem – present at all levels of society – but also one that becomes more likely the lower a person’s household income.
“Taking 11-year-olds as an example, official statistics for England show that around 15% of children in the richest fifth of households are obese, compared with 24% of children in the poorest fifth. The overall percentage for this age group is around twice that for five-year-olds.
“What we know now as far as obesity among children is concerned is that it worsens during the time of primary school – so it is in no sense just an early years problem – and that poverty makes it a lot worse. Poverty reduction and lower levels of income inequality more widely are part of the answer.”
Prof Sheila Hollins, chairwoman of the British Medical Association’sBoard of Science, says a complete ban on advertising junk food would make a real difference.
“Environmental factors, including the promotion of unhealthy food and poor infrastructure for active means of travel, have had a negative impact on people’s eating habits and activity levels and have exacerbated the UK’s obesity problem.
“With an alarming rise in the levels of obesity among children, the BMA is urging the government to introduce a complete ban on the advertising and marketing of unhealthy foodstuffs and make more extensive use of the media to promote healthy lifestyle messages.
“Improved and consistent food labelling is fundamental in enabling consumers to make informed dietary choices, which is why the BMA has repeatedly called for the introduction of a standardised, consistent approach to labelling based upon the traffic-light, front-of-pack labelling.”
This is something that the Children’s Food Campaign also puts at the top of its wish list.
Co-ordinator Malcolm Clark says: “A significant dent on obesity levels is unlikely to happen until the government ensures all companies are changing their marketing habits, and faster and further than they would otherwise have done.”
Public Health England is hoping its latest initiative which asks people to make “simple swaps”, like substituting sugary fizzy drinks for sugar-free or diet alternatives, will help stem the obesity crisis.
This like-for-like swap could save a family up to three-quarters of a 1kg bag of sugar over four weeks, according to the Change4Life Smart Swaps campaign.
Prof Kevin Fenton, director of health and well-being, says: “PHE are committed to helping to tackle obesity through a range of approaches that support action on the local environment to make eating less and being more physically active easier.”
Keep fit programmes
The Association for the Study of Obesity says greater availability of interventions to help people to lose and manage their weight is key.
“This ranges from simple and low-cost programmes for most, with more intensive support available for people who have more severe and complex obesity. In too many towns, GPs cannot discuss obesity with their patients because there is nowhere they can refer their patients if patients want help. Evidence-based programmes are available – they just need to be made available everywhere.
“At the same time the heavy marketing of energy-dense foods and drinks needs to be halted to both support weight loss efforts and to prevent the development of obesity in currently healthy-weight individuals.”
The number of overweight and obese adults in the developing world has almost quadrupled to around one billion since 1980, says a report from a UK think tank.
The Overseas Development Institute said one in three people worldwide was now overweight and urged governments to do more to influence diets.
In the UK, 64% of adults are classed as being overweight or obese.
The report predicts a “huge increase” in heart attacks, strokes and diabetes.
Changes in lifestyle, the increasing availability of processed foods, advertising… have all led to dietary changes”
Steve WigginsOverseas Development Institute
Globally, the percentage of adults who were overweight or obese – classed as having a body mass index greater than 25 – grew from 23% to 34% between 1980 and 2008.
The majority of this increase was seen in the developing world, particularly in countries where incomes were rising, such as Egypt and Mexico.
The ODI’s Future Diets report says this is due to changing diets and a shift from eating cereals and grains to the consumption of more fats, sugar, oils and animal produce.
A total of 904 million people in developing countries are now classed as overweight or above, with a BMI of more than 25, up from 250 million in 1980.
This compares to 557 million in high-income countries. Over the same period, the global population nearly doubled.
At the same time, however, under-nourishment is still recognised to be a problem for hundreds of millions of people in the developing world, particularly children.
Using data published in Population Health Metrics last year, the researchers looked at changing overweight and obesity rates across the regions of the world and by individual country.
The regions of North Africa, the Middle East and Latin America saw large increases in overweight and obesity rates to a level on a par with Europe, around 58%.
While North America still has the highest percentage of overweight adults at 70%, regions such as Australasia and southern Latin America are now not far behind with 63%.
Diet linked to income
The greatest growth in overweight people occurred in south east Asia, where the percentage tripled from a lower starting point of 7% to 22%.
Among individual countries, the report found that overweight and obesity rates had almost doubled in China and Mexico, and risen by a third in South Africa since 1980. Many countries in the Middle East also had a high percentage of overweight adults.
One of the report authors, Steve Wiggins, said there were likely to be multiple reasons for the increases.
More meat, fats and sugar are being consumed globally
“People with higher incomes have the ability to choose the kind of foods they want. Changes in lifestyle, the increasing availability of processed foods, advertising, media influences… have all led to dietary changes.”
We need to act urgently to deal with the scandal of millions of cases of extreme hunger and under-nutrition in children”
He said this was particularly the case in emerging economies, where a large middle class of people with rising incomes was living in urban centres and not taking much physical exercise.
The result, he says, is “an explosion in overweight and obesity in the past 30 years” which could lead to serious health implications.
This is because consumption of fat, salt and sugar, which has increased globally according to the United Nations, is a significant factor in cardiovascular disease, diabetes and some cancers.
The world’s top sugar consumers include the United States, Belgium, the Netherlands, New Zealand, Costa Rica, and Mexico.
To combat the rising tide of obesity, Mr Wiggins recommends more concerted public health measures from governments, similar to those taken to limit smoking in developed countries.
What makes South Korean food so healthy?
He said: “Politicians need to be less shy about trying to influence what food ends up on our plates.
“The challenge is to make healthy diets viable whilst reducing the appeal of foods which carry a less certain nutritional value.”
The report cites the example of South Korea where efforts to preserve the country’s traditional diet have included public campaigns and large-scale meal preparation training for women.
Alan Dangour, a reader in food and nutritional global health at the London School of Hygiene and Tropical Medicine, said urbanisation in many parts of the world had changed people’s eating habits away from traditional, healthy diets.
But he said obesity and under-nutrition often existed side by side, sometimes in the same household.
“We need to act urgently to deal with the scandal of millions of cases of extreme hunger and under-nutrition in children, but we also need to think what happens if we provide lots of extra calories, containing few vitamins, and encourage excess consumption.
Would people in the UK support a tax on fatty foods?
“Clever, joined-up policies are needed.”
A spokesperson from the Department of Health said they recognised that high rates of obesity caused dangerous health conditions and were taking action.
“We are already taking the lead in helping tackle and prevent this challenge, including through the government’s Responsibility Deal with industry, NHS Health Checks, the National Child Measurement Programme in schools and through Change4Life.
“For the first time ever, we’ve given local authorities ring-fenced budgets to tackle public health issues in their local area, including obesity.”
The Department of Health also said that industry and health professionals had a role to play in helping people improve their diet and lifestyles.
The NHS has a “poorly developed” approach to tackling obesity, the college said
Obesity services across the UK are “extremely patchy” and valuable opportunities to help obese patients are often lost, doctors say.
The Royal College of Physicians said hospitals in particular had “poorly developed” systems in place.
Its report said the problems meant services were often just dealing with the symptoms, such as heart disease or diabetes, rather than the cause.
There needed to be a rethink over how to approach the problem, it added.
The UK is now among the most obese nations in the world.
One in four adults are obese – a figure which is predicted to more than double by 2050.
The report recognised that attempts were being made to stem the tide of obesity through health promotion campaigns.
But it said that should not detract from the fact the NHS had to do more to deal with those patients who were already obese.
The only way we will ever tackle the problems caused by obesity is by everyone working together”
Professor Lindsey DaviesFaculty of Public Health
The report pointed out there were wide variations in the way obesity was treated across the UK – particularly in the frequency with which obesity surgery is performed.
It said there needed to be a much more “joined up” approach between hospitals and community services.
To help hospitals should also appoint a doctor to lead on obesity, it added.
Prof John Wass, from the RCP, said: “‘Britain is getting bigger and whilst we try to prevent the increase in obesity, we must also prepare the NHS for the influx of patients presenting with severe complex obesity.
“A patient may arrive at my hospital with coronary heart disease, but if the root cause of their condition is obesity, we must be equipped to deal with that root cause.”
Prof Lindsey Davies, president of the Faculty of Public Health, welcomed the recommendations and said she agreed greater coordination was needed.
“The only way we will ever tackle the problems caused by obesity is by everyone working together,” she added.
But she also urged the government to be more proactive by addressing some of the wider determinants of obesity.
“Obesity is not only caused by how much we each eat or drink: if tackling it were as simple as telling people to eat less and move more, we would have solved it by now.
“Our chances of being obese are also affected by factors like whether we have easy access to affordable fruit, veg and other healthy foods, and if it safe to let our kids play outside.”
A Department of Health spokesman acknowledged the medical profession had a “key role to play”.
He added: “We are committed to tackling obesity and are taking action to help people keep a healthy weight and prevent them needing hospital care for obesity related conditions.”
Datuk Seri Liow Tiong Lai (second from left) and organising chairman of the 9th Allied Health Scientific conference, Dr Tee E Siong (left), talking to participants at the Renaissance Hotel in Kuala Lumpur yesterday. Pic by Nurul Syazana Rose Razman
ALARMING: Malaysians’ unhealthy eating habits causing a spike in non-communicable diseases
KUALA LUMPUR: The Health Ministry yesterday expressed concern over a host of non-communicable diseases (NCD) adopting a communicable trend in the country.
Minister Datuk Seri Liow Tiong Lai said the tide of NCD was serious especially obesity, which was passed down from parents to children.
“The ministry will work on strengthening preventive care and create awareness to help the public understand their responsibility on health,” he said in his speech before launching the 9th Allied Health Scientific conference here.
The other NCDs are diabetes, high blood pressure, high cholesterol, cardiovascular ailments, cancers, chronic lung diseases, emerging and re-emerging infections such as tuberculosis, dengue, and the growing number of psychiatric problems.
Liow said the ministry would work with dieticians, nutritionists, doctors and specialised therapists to provide the public with the needed assistance to care for their health.
“All non-communicable diseases are preventable.”
The Malaysian Council for Obesity Prevention (MCOM) president Jong Koi Chong blamed Malaysians’ unhealthy eating habits which caused a spike in NCDs.
“Late dinners and suppers are not encouraged as the metabolic rate is low during this period, making it easy for fat to accumulate,” he said, adding more youth were frequenting 24-hour food joints which served high caloric food.
National Heart Institute chief dietitian Mary Easaw-John said most Malaysians saw obesity as “body size” and not a disease.
“Those who are obese or overweight do not see it as a medical condition, so they don’t consult a doctor. The general attitude is to let it be.”
Easaw John said food outlets should consider offering healthy food options. For example, she said if they served fish curry with coconut milk, there should also be steamed fish.
She added the government should come up with a programme that provided incentives to food outlets which offered such options.
The National Health and Morbidity Survey 2011 showed NCD cases were on the rise and data from government hospitals also showed between 38 per cent and 40 per cent of total deaths were due to NCD.
Statistics also showed 2.6 million adults were obese and an estimated 477,000 children below the age of 18 years were overweight.
On the Allied Health Professions Bill, which would be ready for public viewing for three weeks from Oct 1, Liow said the bill was also available on the ministry’s website, adding feedback was welcome.
There are about 40,000 public and private allied health professionals in the country, who work with doctors and nurses to help patient recovery by conducting rehabilitation.
At the age of 19, Mr Lawrence discovered he had diabetes during his National Service pre-enlistment health check.
Despite having to pop pills every few hours to keep his condition under control, he did not take his illness seriously and continued consuming five heavy meals and several cans of soft drinks a day.
“At that point, it didn’t hit me that diabetes was for life. I didn’t take it seriously, even though my parents were shocked that I got diabetes at such a young age,” said the operations executive, who once tipped the scales at 117kg.
Singapore has one of the highest rates of diabetes among developed nations. Fast becoming a global epidemic, diabetes affects about 11.3 per cent of the world population.
About nine in 10 diabetics here suffer from Type-2 diabetes, which was traditionally named Adult-Onset Diabetes as it affects only adults, said Dr Tham Kwang Wei, Director of the Obesity and Metabolic Unit at Singapore General Hospital (SGH).
Experts like Dr Tham are concerned about the growing number of teenagers and younger adults who are diagnosed with the condition that affects mostly those above the age of 40.
Just eight years ago, diabetes affected only 0.5 per cent of those aged 18 to 29 years, according to the 2004 National Health Survey.
By 2010, the figure had doubled to 1 per cent.
Among 30-something adults, diabetes statistics have similarly jumped from 2.4 per cent in 2004 to 4.3 per cent in 2010.
These figures may be under-representative of the actual situation, said Dr Tham, who spoke on the topic at the SingHealth Duke-NUS Scientific Congress on Saturday. This is because more than half of those with diabetes go about their daily lives undiagnosed as symptoms can go unnoticed in the early stages.
Dr Tham, whose youngest diabetes patient is a 16-year-old, said that one in 10 of her patients is under 40 years old.
Obesity the main culprit
Dr Tham noted that, in 2004 to 2010 when diabetes rates spiked, there was a dramatic increase in national obesity rates. Excess weight messes up your body’s ability to control blood sugar levels.
“Another factor is physical inactivity,” she added.
“The majority of Singaporeans are rather physically inactive, especially when they have sedentary jobs and the convenience of modern transportation.
“Many commercially available foods are also calorie-dense and highly processed with a lack of fibre in our diet.
“All these factors lead to higher risk of obesity which in turn increases one’s risk of diabetes,” Dr Tham said.
Other lifestyle factors include stress, as well as the lack or poor quality of sleep, which are common among Singaporeans.
Dr Shanker Pasupathy, Senior Consultant of Bariatric/Metabolic and Vascular Surgery, Department of General Surgery at SGH, explained that the excess “fat mass” in overweight and obese people is the main driver for insulin resistance.
Explaining how Type-2 diabetes develops in those who are overweight, he said: “The body (specifically the beta cells in the pancreas) needs to produce more and more insulin in order to effectively lower the blood sugar level after a meal.
“This leads to a ‘burnout’ of the beta cells and, therefore, insulin levels fall, resulting in high circulating blood sugar levels.”
Chronically high blood sugar levels can damage the blood vessels and tissues, leading to severe and permanent complications such as heart failure, stroke, nerve, kidney and foot damage, Dr Tham warned.
Complications at an earlier age
There are also concerns that these potentially severe problems could occur in younger patients.
“The younger a person is at the onset of diabetes, the longer he (or she) will be exposed to (its) ill effects.
“About half of patients who have a heart attack have diabetes. This is an alarming association,” said Dr Tham.
She noted that younger patients tend not to treat their conditions seriously, since many do not experience symptoms until it is too late and have other priorities like careers and family on their minds.
For Mr Lawrence, the reality of his illness only sunk in three years ago, when his doctor told him that he had exhausted all oral medication options. If he continued with his unhealthy lifestyle, he would soon require daily insulin jabs.
Last year, he underwent a gastric bypass procedure to keep his weight under control. Since then, Mr Lawrence has shaved off about 40kg off his hefty frame and has turned his lifestyle around.
According to Dr Shanker, recent clinical trials show that there is approximately an 80-per-cent chance that diabetes may be reversed after a gastric bypass.
Although he still takes multiple meals a day, Mr Lawrence’s portions are a fraction of what he used to eat.
“I’ve also totally weaned off soft drinks. Now I’m totally off the medications I was taking for diabetes, high blood pressure and cholesterol.
“All of my friends and family are happy to see the positive change in me,” he said.
White fat is the ‘bad’ stuff which stores energy rather than burning off calories
What produces 300 times more heat than any other organ in the body? What stops a baby from freezing to death if left in the cold? The answer to both questions is “brown fat”.
Scientists have discovered that this type of fat is a good thing because it produces lots of heat by burning calories.
Unlike white fat, which clings to our hips and expands our ageing waistlines, brown fat keeps the weight off.
And that’s why the race is on to find out more about brown adipose tissue, also known as brown fat, and how humans could use it to our advantage.
If we activate brown fat, we can eat more and not gain weight”
Prof Sir Stephen BloomImperial College London
When we’re born we have lots of brown fat in our bodies, wrapped round the central organs to keep us warm, to help us adapt to life outside the womb.
As we grow, however, the brown fat content of our bodies decreases.
Researchers at the University of Nottingham have been using heat-seeking technology to find out if brown fat is still present in children and adults.
In the neck
Professor Michael Symonds and Dr Helen Budge from the University’s School of Clinical Sciences say their research, published in the Journal of Pediatrics, shows that the neck region in healthy children produces heat.
“There is only about 50g of brown fat in the neck region and it switches on and off throughout the day as it’s exposed to different temperatures or if you exercise or eat,” says Prof Symonds.
Thermal imaging shows brown fat on a child’s neck (in red) when their hand is put in cold water
But this capacity is much greater in young children compared with adolescents and adults.
He says that the challenge is now to use this knowledge to find out what factors might switch on brown fat, and therefore prevent excess weight gain.
“The more we know about what switches on brown fat the better. It may have an immediate effect which can be retained as you get older.
“This may provide new insights into the role of brown fat in how we balance energy from the food we eat, with the energy our bodies use up.”
But could it have a role to play in fighting obesity too?
It’s well-known that the UK has a weight problem. Just over a quarter of adults were classified as obese in 2010, a report from the NHS Health and Social Care Information Centre said earlier this year.
We could add a thermogenic index to food labels to show whether that product would increase or decrease heat production…”
Prof Michael SymondsUniversity of Nottingham
If the power of brown fat can be harnessed then white fat’s days could be numbered.
It’s a nice theory, says Prof Sir Stephen Bloom, head of division for diabetes, endocrinology and metabolism at Imperial College London.
“If we activate brown fat, we can eat more and not gain weight. But we would waste energy unnecessarily, we would sweat a lot and forever be opening windows.
“We’d be hot and thin.”
Anything that could mean calories are burned rather than being stored as fat sounds like a good idea – but there are dangers in using agents to activate body tissue.
“Agents have potential for toxicity. It’s great if it works and it’s safe, but everyone is nervous of the side effects of obesity therapies,” Prof Bloom says.
Previous research on rodents and small mammals shows that they, like babies, rely on brown fat to keep warm.
“But this might not be so applicable in humans, particularly adults. That much brown fat is not natural in humans.
The baby’s back is very warm (coloured red) due to the presence of large amounts of brown fat protecting its organs
“It would be hard work to stimulate everything that way.”
Prof Symonds is more positive, believing that his team’s research using thermal imaging could lead to more useful information on what we eat.
“Potentially we could add a thermogenic index to food labels to show whether that product would increase or decrease heat production within brown fat.
“In other words whether it would speed up or slow down the amount of calories we burn.”
So fat is not as simple as it seems. There are different types and the brown stuff is much better than the white.
But we have no control over the quantities of each kind in our bodies, nor how it is managed.
In the future, Nottingham researchers will look at how nutrition, exercise, and environmental and therapeutic interventions could have an impact on brown fat and its unique heat-generating properties.
In the meantime, Prof Bloom says it’s a very promising area to work on.
“It could be a help in the fight against obesity, diabetes and heart problems.”
Are we nearly there yet? “There’s a long way to go. A decade at least.”
The war against white fat is only just beginning.
A*STAR scientists in Singapore have made what’s believed to be groundbreaking discovery of the mechanism that controls obesity, atherosclerosis and potentially, cancer.
Scientists from the Institute of Molecular and Cell Biology (IMCB) and the Singapore Bioimaging Consortium (SBIC) say they have found a new signalling pathway that regulates both obesity and atherosclerosis.
The team showed, for the first time, that mice deficient in the Wip1 gene were resistant to weight gain and atherosclerosis via regulation of the Ataxia telangiectasia mutated gene (ATM) and its downstream signalling molecule mTor.
A*STAR says these groundbreaking findings were published in the journal Cell Metabolism on 3rd July and may provide significant new avenues for therapeutic interventions for obesity and atherosclerosis.
Obesity and atherosclerosis-related diseases account for over one-third of deaths in the Western world.
Controlling these conditions remains a major challenge due to an incomplete understanding of the molecular pathways involved.
Atherosclerosis, a progressive disease of the large arteries, is an underlying cause of many cardiovascular diseases.
In Singapore, 10.8% of its population is obese, and cardiovascular disease accounted for 31.9% of all deaths in 2010.
Obesity and atherosclerosis are accompanied by the accumulation of lipid droplets in adipocytes (fat cells) and in foam cells respectively.
Foam cells can subsequently rupture, damaging blood vessels, and contributing to further progression of atherosclerosis.
The scientists discovered that Wip1 deficient mice, even when fed a high-fat diet, were resistant to obesity and atherosclerosis by preventing the accumulation of lipid droplets.
This appeared to be through increased autophagy, the normal process by which the body degrades its own cellular components.
They showed that the Wip1 deficient mice exhibited increased activity of ATM which decreased mTor signalling, resulting in increased autophagy.
This degraded the lipid droplets and suppressed obesity and atherosclerosis.
“This is the first time that Wip1-dependent regulation of ATM-mTor pathway has been linked to authophagy and cholesterol efflux thus providing an entirely new avenue for treatment of obesity and atherosclerosis,” said Dr Dmitry Bulavin, Senior Principal Investigator at IMCB and lead author of the paper.
The scientists are hopeful that the ATM-mTor pathway could similarly map onto cancer to suppress tumour progression.
Similar to suppression of obesity and atherosclerosis, activation of autophagy in cancer cells could result in degradation of cellular content that is essential for cancer cells to sustain rapid proliferation.
This, in turn, will result in suppression of cancer growth.
Said Dr Dmitry Bulavin, “We are building on this research to investigate if the same mechanism could also control tumour progression and hence potentially unlock new therapeutic treatments targeting Wip1, ATM and mTor in cancer as well and the preliminary results are promising.”
This discovery also adds to the growing significance of ATM as an important gene with a key role in protecting us from major pathological conditions. Previous work has established Wip1-dependent regulation of ATM as a potent regulator of tumorigenesis via activation of tumour-suppressor p53.
Together, these three pathological conditions – obesity, atherosclerosis and cancer – account for more than 70% of mortality worldwide, making ATM-related pathways very attractive therapeutic targets.
Prof Hong Wanjin, Executive Director of IMCB, said, “This is the first time that these important molecules have been integrated into a linear pathway that plays a prominent role in controlling obesity and atherosclerosis. It is a fine example of how fundamental research can shed light on biological and medical questions to potentially open new avenues of formulating therapeutic strategies for the benefit of patients.”