Fat doubles risk of bowel cancer says study

Obesity doubles the risk of young women developing bowel cancer, say American researchers.

A study of nearly 90,000 women, by researchers at the Albert Einstein College of Medicine in New York, showed that excessive weight increased the chances of developing the disease in women before menopause.

"Our data suggest that obesity is associated with a two-fold increased risk of colorectal cancer, and that at most it is associated with a small reduction in risk in postmenopausal women," said Dr Peter Terry in a report in the journal Gut.

The scientists suspect that before menopause excess fat in the body increases levels of blood insulin and other chemicals which raise the risk of cancer.

But afterwards fatty tissue could be a source of the female hormone oestrogen, which could counteract the harmful effects of insulin.

Body mass index (BMI) is the standard measure of obesity. It is calculated by dividing weight in kilograms by height in metres squared. A BMI of 30 is considered obese and 35-plus is very obese.

Obesity, which is reaching epidemic proportions in some countries, also increases the risk of diabetes, respiratory disease, muscle and skin problems, infertility, high blood pressure, stroke, heart disease and hormone-related cancers.

In a separate study published in the journal, scientists at Royal Victoria Hospital in Belfast, Northern Ireland, reported that folic acid could help to cut the chances of developing bowel cancer in high-risk patients.

All of the patients in the study had pre-cancerous growths in their bowel. Half received folic acid supplements and the remainder were given a placebo or dummy pill.

The researchers took biopsies at four-week intervals to determine the impact of the supplements.

Patients taking folic acid had fewer proliferating cells than in the placebo group.

"The report highlights the need for further investigation on the role of folate as a chemo-preventive agent in patients at risk of colon cancer," the scientists said.

Colon and rectal cancer affects more than 3.5 million people worldwide each year and is a leading cause of death in developed countries.

If it is detected and treated early, the survival rate is good.

Scientists suspect it is caused by a combination of genetic and lifestyle factors.

- REUTERS

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