Overweight is a risk factor for cancer. However, compared with women who were overweight men were more at risk of cancer.
Excessive body fat is the direct cause of four of the 10 cases of cervical cancer. Those who have a body mass index of 25 or more, three times more at risk than women of ideal weight. These alarming figures published last week by the World Cancer Research Fund in the journal Lancet Oncology.
High BMI or obesity can significantly increase the risk of breast cancer in post-menopausal women and colon cancer. Obesity also increases the risk of pancreatic cancer, esophagus (gullet) and kidney cancer in men and women.
The scientists reported that 20,000 cases of cancer in the UK each year are directly related to obesity.
"But how obesity may increase the incidence of cancer is the 'subject of heated debate in the clinical and scientific community'," said Professor Nicholas Lemoine, director of Barts Cancer Institute at Queen Mary University, London.
Compared with men, women who are obese are more at risk of cancer. Every year in the UK, 13,000 women with cancer are associated with obesity, twice that of the men. Two common types of cancer is cervical cancer and postmenopausal breast cancer.
A total of 13,000 women per year of cancer are associated with obesity, twice the number of men affected by cancer. Experts suspect, estrogen, especially after menopause, could be the trigger.
Before menopause, estrogen made by the ovaries to thicken the lining of the uterus in preparation for ovulation. Every month, progesterone is also produced to facilitate the lining of the uterus shed during menstruation.
Estrogen also made by the body fat in women. The more fat cells you have, the more estrogen produced.
"After menopause, women with excess body fat will continue to produce high amounts of estrogen and it will coat the lining of the uterus. In fact, there was no effect of the influence of progesterone. This is likely to lead to cervical cancer," said Lam Dr.Matthew, researchers.
High exposure to the hormone estrogen after menopause will also stimulate the growth of abnormal cells in the breast, triggering the growth of estrogen-responsive breast cancer.
This explanation is also supported by a large research program in the United States and Sweden since 2009, where scientists keep track of cancers associated with obesity in two groups of patients: one that never binding intestinal surgery for weight loss, and which are not.
In a Swedish study, women who perform these operations are less likely to suffer from obesity-related cancers. 42 percent lower risk.
However, studies report different patterns in men, where estrogen is not a factor to cancer.
Different fat distribution in men and women's body could also explain why men are more at risk of cancer in areas of the body close to the stomach. This is because men typically accumulate fat in the abdomen, while women spread in all parts of the body.
