Wednesday, February 25, 2009

Overweight, shorter lifespan

PARIS - SIMPLY being overweight, but not obese, from an early age boosts the risk of premature death by a third - as much as smoking up to 10 cigarettes a day, researchers in Sweden reported Wednesday.

People who are clinically obese by the age of 18 more than double that risk, putting themselves in the same danger zone as long-term heavy smokers of normal weight, they found. And combining the two factors accumulates the risk: an obese heavy smoker, for example, is nearly five times as likely to die prematurely than a non-smoker who is neither too thin nor too fat.

At least a billion people in the world are overweight, and nearly a third of them are obese, according to the World Health Organisation (WHO). Obesity rates have soared over the last three decades, especially among children.

Earlier studies have shown that being excessively fat shortens lifespan and leads to increased rates of chronic disease such as diabetes and arteriosclerosis.

But researchers have disagreed sharply up to now on whether being above ideal weight without crossing the line to obesity takes years off one's life. Nor have previous studies directly compared the impact on mortality of smoking and excess weight.

The study designed by Martin Neovius of the Karolinska Institute in Stockholm goes a long way to settling the debate, and shows clearly for the first time that being too heavy can be as dangerous as smoking a couple of packs a day.

Mr Neovius and colleagues analysed data for 45,000 men who underwent mandatory military conscription tests in Sweden in 1969 and 1970 at the age of 18.

The follow up period was, on average, 38 years. During that time, 2,897 subjects died. The lowest death rate, as expected, was among non-smokers of normal weight.

But researchers were surprised to find that being obese carried a greater risk of premature death than being a heavy smoker. Even more startling, however, were the dangers of being overweight. 'What we show is that for the overweight, there is a significantly increased risk of premature death, similar to smoking one-to-ten cigarettes a day,' said Mr Neovius in a phone interview.

The Swedish study also found that being severely underweight - a BMI of under 17 - carried about the same risk of early death as being overweight or a light smoker. -- AFP

Tuesday, February 24, 2009

Breast Cancer

One in every nine women in the UK will develop breast cancer at some point in her life - more than 41,000 cases are diagnosed each year.

It has become the most common cancer in the UK, and is the leading cause of death for women aged 34 to 54.

More rarely, men can also develop this cancer.

Despite recent improvements in the mortality rates, due to better treatments and earlier detection, the UK still has one of the highest mortality rates in the world.

But research is beginning to reap dividends in new ways of understanding how breast cancer cells work.

Professor Charles Coombes, who is director of Cancer Research UK's research laboratory at Imperial College London, says there is cause for optimism.

"The more we understand about how these cells behave, the more likely we are to understand what happens with breast cancer.

"That revolution is ongoing. We are going, I think, to be looking at improved results over the next 20 or 30 years."


The most common way that a potential problem is detected is when physical changes are noticed in the breasts.

Regular breast screening may also highlight changes in the breast.

The key is for the woman to know what "normal" is - then changes can be noticed.

Examples of the kind of things to look out for include:

* a change in outline, shape or size of the breast
* puckering or dimpling of the skin
* any lump or thickening in the breast or armpit
* any flaking skin or discharge from the nipple
* unusual pain or discomfort

Any changes should be reported to a doctor - although most will turn out not to be cancerous.

Many lumps will be picked up with mammograms - x-rays of the breast taken every few years as part of the NHS national screening programme.

If a lump is found, techniques used to investigate it include ultrasound and "fine needle aspiration", which will show whether the area is a solid lump or is a cyst.

A biopsy may also be carried out, so that a sample of the lump can be examined in a laboratory.


The precise reasons why a woman develops breast cancer are still unknown, but are thought to be a combination of genetic, environmental and lifestyle factors.

Scientists have identified two genes which are more likely to be defective in a breast cancer patient than someone without breast cancer.

These genes are also blamed for some other cancers.

However, even the two mutated genes are thought only to be responsible for approximately 5% to 10% of breast cancer cases.

Hormones seem to have an important role in breast cancer. Research has shown a link between levels of the female sex hormone, oestrogen, and the risk of developing breast cancer.

Women who take certain types of hormone replacement therapy are at higher risk of breast cancer.

Women who have their first child later in life also appear to be at higher risk of developing breast cancer.


If cancer is confirmed, then there are variety of treatments available, depending on the size of type of the tumour, and whether doctors believe it has or could have spread.

Most women with breast cancer do not need to have a breast removed.

The bigger the tumour relative to the size of the breast, the more likely that mastectomy will be recommended.

In a procedure known as a "lumpectomy", just the cancerous lump is removed.

After both kinds of operation, radiotherapy may be given to reduce the chance that the cancer will return.

If the tumour is very large, treatment may be given to reduce the size of the tumour before the operation takes place.

In most cases, the surgeon also removes lymph nodes under the arms to find out if the cancer cells have spread into the lymphatic system.

This is a network of vessels which link different parts of the body - if the cancer has reached the lymph nodes, it is more likely to have spread to other parts of the body.

The breast cancer cells may be tested to see if they are sensitive to the sex hormone oestrogen, and are more likely to grow if the hormone is present.

If this is the case, the woman may be given a drug which blocks the action of the hormone, restricting the cancer growth.

However, as some forms of this drug produce menopausal symptoms, younger women whose breast cancer is more likely to have spread could be offered a combination of surgery and chemotherapy instead.

Following breast surgery, or even breast removal, reconstructive surgery is possible to restore the appearance of the breast.

This could even be carried out at the same time as mastectomy.

Techniques have improved in recent years, and surgeons are able to more closely mimic the appearance of the other breast, giving a normal appearance in clothes.

Some of the techniques employed include the use of implants, fat from other parts of the body, such as the tummy, or even a back muscle which is bent round to form the new breast.

Bowel Cancer

Bowel cancer may also be called rectal, colorectal or colon cancer.

It is the UK's third most common cancer, with more than 35,000 cases diagnosed in 1999.

It is not easy to treat, mainly because it is often detected only once well-established - and possibly spread beyond the bowel itself.

Doctors urge the public to be more aware of the warning signs of bowel problems, and report them promptly to doctors.

However, estimates suggest that nine out of 10 bowel cancers detected early can be successfully treated.

However, once the cancer has spread beyond the wall of the bowel, it becomes harder to treat.

Professor David Kerr, from the University of Oxford, said: "Surgery still remains the only definitive and perhaps curative treatment - sadly though, in half those patients who have that operation, the cancer will come back.

"By the time patients present with the bowel cancer, which can remain hidden for many years, there can be tiny seeds of the cancer which have spread beyond the bowel."


The problem with bowel cancer symptoms is that they could easily be caused by something less life-threatening.

They are:

* rectal bleeding
* a change in bowel habit
* a feeling that you need to empty your bowels even when you have just been to the toilet
* abdominal pain

These symptoms are not uncommon - and could be a sign of something far less serious.

However, doctors advise that if such symptoms persist for longer than a couple of weeks medical attention should be sought.

Often, a GP will carry out a "rectal examination" to check for any abnormal changes.

This involves putting a gloved finger in the rectum - this should be a painless procedure.

To investigate these symptoms, doctors often ask patients to undergo sigmoidoscopy or colonoscopy.

Both these procedures involve inserting a probe into the bowel. This has a tiny camera on the end which allows the doctor to look for cancerous areas on the bowel wall.

This can be uncomfortable, but is very seldom a painful experience.

Sometimes a dye which shows up on x-rays is injected into the lower bowel to help doctors spot signs of cancers.

Doctors may order more tests, such as CT scans, to check to see if the cancer has spread to involve other organs such as the liver.

In November 2002 the government announced the foundation of a national screening programme for bowel cancer, which is now well underway.

This could be carried out either with sigmoidoscopy, colonoscopy or fecal occult blood tests, which involve taking a stool sample which is then checked for signs of bleeding.


There is believed to be a genetic link to a small number of bowel cancer cases, as those with a family history are more likely to develop it themselves.

However, diet is a key factor identified by scientists - certainly the low fibre, high fat diets favoured in the Western world are thought to have increased the rates of bowel cancer.

People are encouraged to eat plenty of fresh fruit and vegetables, as this appears to reduce the risk.

An increase in fibre in the diet has also been linked to a reduced risk of bowel cancer.


The main option for treating bowel cancer is surgery , and if the disease can be caught before it breaks through the bowel wall, the patient's chances are much higher.

In these cases, further treatment may not be necessary. This operation is called a bowel "resection" by doctors.

However, once the cancer has spread beyond the bowel, chemotherapy is used.

Radiotherapy is sometimes given if the cancer is inoperable, or perhaps to shrink a tumour to make an operation easier.

HIV rates among gay, bisexual men growing in Asia

HONG KONG: The AIDS virus is spreading rapidly among gay and bisexual men in Asia as younger people shun condoms and authorities fail to increase
awareness of the disease, health officials said Friday.

The epidemic will worsen dramatically in coming years unless there is better education and stronger political will to combat the disease, warned Massimo Ghidinelli, the World Health Organization's regional adviser on HIV/AIDS.

His comments came at a news conference after a seminar in Hong Kong at which regional AIDS experts discussed the growing trend.

Asia is believed to have the world's largest number of men who have sex with other men, with a preliminary estimate of 10 million, according to WHO.

While describing the figure as "extraordinary high," Ghidinelli said it still appeared to be conservative because of the stigmatization of male-to-male sex.

WHO said fragmentary information from the region indicated a rapid spread of HIV among gay and bisexual men, but that full data weren't available. The seminar was called to strengthen efforts to study and address the problem, it said.

Ghidinelli said low condom use among younger men in male-to-male relationships was fueling the transmission of HIV.

"Younger men engaging in sex with men are entering into a sexual arena without the same level of awareness and without taking the same level of protection that the older generation was taking," Ghidinelli told a news conference.

Ghidinelli said the AIDS experts agreed at the conference to set up a regional task force to collect information on male-to-male transmission and to strengthen measures to fight the disease.

Gene responsible for weight gain identified

LONDON: Scientists have finally solved what they claim is the "fat gene" mystery, a key finding that sheds light on why some people can eat but
never put on weight while others struggle to shed flab.

Earlier studies suspected that genetic differences were responsible for weight gain and singled out the FTO gene as the main culprit.

Now, a team, led by Düsseldorf University in Germany, has found concrete evidence that the gene may control the rate of the metabolism, making its carriers leaner than those without it.

The scientists reached the conclusion after carrying out experiments on mice. Those with the FTO gene entirely were found to remain lean. The animals remained thin despite eating large amounts of food and being inactive, the 'Nature' journal reported in its latest edition.

According to the scientists, the breakthrough could herald a raft of new treatments for obesity.

"This finding will promote research into the development of drugs that modulate FTO activity. We strongly suspect that, in man, FTO might have more complex effects on both food intake and energy expenditure than has been so far suggested and that it is still not clear what the overall effect of inhibiting FTO in humans would be," lead scientist Ulrich Ruther was quoted by 'The Daily Telegraph' as saying.

Experts have welcomed the research. Professor Stephen O'Rahilly, a metabolism expert from Cambridge University, said: "Genetic variation close to the FTO gene is definitely associated with obesity in humans, but, until now, it was not clear whether this genetic variation was likely to influence obesity by altering the expression or function of the FTO gene itself or some neighbouring gene.

"This is a bit puzzling as several recent studies have suggested that the variant in the human FTO gene that increases the risk of obesity has effects on appetite and food intake but does not seem to have any effect on how quickly energy is burned off.

"So, this work provides a crucial piece of evidence supporting the notion that the FTO gene itself is likely to be involved in the effects of common human genetic variants on body fat."

Saturday, February 14, 2009

Myths about sugar and health

LONDON: Replacing sugar with other sources of carbohydrates does not necessarily make you lose weight, according to a scientific review study.

Busting such misconceptions about the impact of sugars on health, the study observes that what appears more important is the total amount of energy intake, the energy density of the foods and the quality of the diet.

The evidence shows that added sugars do not necessarily compromise a person's intake of micronutrients. The "micronutrient dilution" myth that eating added sugars dilutes the nutrient density of a person's diet appears mostly due to misreporting and methodological constraints.

Finally, although sugar consumption has traditionally been associated with poor dental health, the experts pointed to the importance of the frequency, more than the amount, of consumption of all sugars and fermentable carbohydrates.

Nowadays, for the prevention of tooth decay, the widespread use of fluoridated toothpaste and good oral hygiene play a more important role.

"The results provide a much needed update of the overall scientific evidence on sugars and suggest that new randomised controlled intervention studies of sufficient size and duration are required," said Andreu Palou, who chaired the expert workshop that looked at the current available scientific evidence.

The combined impact of many dietary and lifestyle factors such as physical activity, excessive calorie intake and weight gain, and their interactions, have to be taken into account.

Obesity and low physical activity are causally related to the development of insulin resistance and its progression towards type 2 diabetes.

There is convincing evidence from randomised controlled trials (RCT) that weight loss and moderate physical activity are beneficial in improving insulin sensitivity and preventing type 2 diabetes, said a Comité Européen des Fabricants de Sucre (CEFS) release. CEFS represents all European sugar manufacturers and refiners among European Institutions.

Enzyme that is key to healthy skin

Washington: Scientists have found that an enzyme associated with the synthesis of fat in the body is also the key to healthy skin and

The enzyme is DGAT1. Mice lacking this enzyme are lean, resistant to diet-induced obesity, more sensitive to insulin and leptin, and have abnormalities in mammary gland development and skin.

When Gladstone Institute of Cardiovascular Disease (GICD) researchers used genetic engineering to delete the enzyme in mice, they found its absence caused levels of retinoic acid (RA) to be greatly increased in skin, resulting in hair loss.

"For some time, we have been studying the enzymes that make triglycerides," said Robert V. Farese, Jr, senior investigator and co-author of the study. "We found that one of these enzymes is a major regulator of retinoic acid actions in the skin."

RA, which comes from vitamin A (retinol), has been used to treat skin disorders, such as acne and psoriasis, and certain cancers, but it is fairly toxic and must be carefully controlled.

In mice without DGAT1, the skin was very sensitive to retinol. The loss of DGAT1 also caused alopecia, or hair loss. Both of these effects could be prevented by depriving the mice of a source of retinol in their diet, said a GICD release.

It turns out that DGAT1 can convert retinol to a relatively inert storage form. Without DGAT1, this ability is lost, and any excess retinol in the skin can be converted to RA.

Thursday, February 12, 2009

Exercise cuts colon cancer risk

Taking exercise can cut the risk of the most common kind of bowel cancer by a quarter, research suggests.

US scientists, who reviewed 52 previous studies, calculated the most active people are 24% less likely to develop colon cancer than the least active.

Colon cancer is the most common form of bowel cancer, a disease which affects more than 36,500 people a year in the UK, causing 16,000 deaths.

The study appears in the British Journal of Cancer.

The study took into account many different types of physical activity including occupational activity like manual labour, as well as more traditional leisure-time activity such as running or going to the gym.

Lead researcher Dr Kathleen Wolin, from the Washington University School of Medicine in St Louis said: "These results give us a very reliable calculation of the positive effect that exercise can have on reducing colon cancer risk.

"It's very positive to see that exercise has such a clear benefit in reducing cancer risk and we hope it will encourage people to enjoy a healthy active lifestyle as well as treating it as a way to minimise their colon cancer risk."

Dr Wolin said she hoped it would eventually be possible to give individuals a detailed breakdown of how they could reduce their chances of cutting their risk of bowel cancer tailored to their own specific circumstances.

Sara Hiom, director of health information at Cancer Research UK, said: "One hundred people a day are diagnosed with bowel cancer in the UK alone, so it's imperative that we do all we can to prevent the disease.

"We know that around half of all cancers could be prevented by changes to lifestyle.

"Maintaining a healthy bodyweight is one of the best ways to lower the risk of bowel and other cancers - potentially helping to avoid an estimated 13,000 cases each year."

Prostate cancer urine test hope

US scientists have moved a step closer to a simple urine test to distinguish between the benign and aggressive forms of prostate cancer.

Some prostate cancers are slow-growing, while others require rapid treatment.

But telling them apart can be difficult and some patients undergo unnecessary surgery or radiation treatment.

The latest study, published in Nature, links a group of small molecules produced by the body to the aggressive form of the disease.

In theory, testing for their presence should enable doctors to determine whether a patient has an aggressive form of prostate cancer - and requires urgent action.

In contrast, patients with benign prostate cancer often end up dying of other conditions because their tumours are so slow to develop.

However, the researchers, from the University of Michigan, have stressed their work is still at an early stage, and a test is still around five years away.

Prostate cancer is the most common cancer in men in the UK, with well over 30,000 new cases diagnosed each year.

Lead researcher Professor Arul Chinnaiyan said: "One of the biggest challenges we face in prostate cancer is determining if the cancer is aggressive.

"We end up over-treating our patients because physicians don't know which tumours will be slow-growing.

"With this research, we have identified a potential marker for the aggressive tumours."

Sample analysis

The researchers examined 1,126 molecules produced by the body in a total of 262 samples of tissue, blood or urine.

They pinpointed about 10 molecules - or metabolites - that were more often present in samples taken from patients with advanced cancer.

One metabolite in particular, sarcosine, was often found at elevated levels in samples taken from patients with advanced cancer, or cancer that had spread, but not at all in samples taken from healthy tissue.

In fact, sarcosine was a better indicator of advancing disease than the traditional marker, a protein called prostate specific antigen.

The research suggests that sarcosine plays a role in helping cancer to spread, and may be a potential target for future new drugs.

Professor Malcolm Mason, a cancer expert at the University of Cardiff, said: "This result is extremely interesting.

"It raises the possibility of telling the difference between the type of cancer that does no harm - which we term 'the pussycat' - from the type that does - which we call 'the tiger'.

"If we are able to distinguish the tiger from the pussycat it could make a real difference."

John Neate, of The Prostate Cancer Charity, said: "It is too soon to say if the results of this study are a blind alley or a breakthrough but so far results are promising enough for research to continue and could lead to the development of a new test for prostate cancer."