London, Feb 15 : Your chances of developing five different types of cancer escalate by 50 percent if you are overweight or obese, according to a new study.
Researchers at the University of Manchester discovered that those who put on weight equal to a five-point increase in the body mass index (BMI) were at considerable risk of contracting cancer of the colon, breast, skin, thyroid.
The researchers said that there was a 50 percent increase in the chances of developing the cancers if a person's weight goes up by more than two stones.
For the study, the team combined data from more than 200 sets of data, including more than 282,000 people that considered the impact of weight on 15 cancer sites.
Increased weight was most strongly linked to an increased risk for cancer of the esophagus in men and women and for endometrial and gallbladder cancers in women.
A modest association was found between excess weight and the risk for more common malignancies such as postmenopausal breast cancer in women, colon cancer in men, and blood cancer in both sexes.
But carrying extra weight was not associated with an increase in risk for prostate cancer in men, premenopausal breast cancer and ovarian cancer in women, and lung cancer in men and women.
"We were surprised to find associations to both common and less common cancers. We also saw very clear differences between [obesity-related] risk at different sites between the sexes," the Telegraph quoted lead researcher Andrew G. Renehan, as saying.
Renehan and colleagues used body mass index (BMI) measures from the studies to assess risk.
BMI is a numerical measure of fatness based on a person's weight relative to height. A BMI of 18.5 to below 25 is considered normal weight, while 25 to just under 30 is considered overweight, but not obese. Someone is considered obese if they have a BMI of 30 or above.
In men and women, each 5-point increase in BMI was associated with a roughly 50 percent increase in relative risk for esophageal adenocarcinoma.
They also found that men who gained more than two stones were 50 per cent more likely to develop oesophageal cancer and a third more likely to suffer thyroid cancer. Their chances of getting colon and kidney cancer increase by 24 per cent; they are also at a smaller but significant risk of rectal and skin cancer.
Women who are similarly overweight increased their chances of cancer of the womb lining and gallbladder by 59 per cent. They also have more than a 50 per cent increased risk of oesophageal cancer and are a third more likely to develop kidney cancer.
The findings are published in the medical journal The Lancet.