Researchers Warn Obesity Is a Risk Factor for Breast Cancer

Researchers at the American Institute for Cancer Research (AICR) warn that obesity appear to be a risk factor for developing breast cancer, and the nation's current obesity epidemic may drive up cancer rates over the coming years.

After conducting a thorough review of existing scientific literature on the obesity-cancer link, researchers found a growing number of studies showing that obesity is definitely a factor in some of the most common forms of cancer.

Evidence that obesity increases the risk of developing cancer is most consistent for breast cancer in post-menopausal women. Fat tissue is a source of estrogen, and obese and overweight women continue to expose their bodies to the effect of estrogen for as long as they carry significant amounts of fat tissue. This extended lifelong exposure to estrogen is linked to the increased risk of breast cancer in women after menopause.

Although the highest risk for developing cancer is seen in obese individuals, there is some consensus in medical literature that overweight people also have a higher risk for cancer, with the risk increasing as their body mass index increases.

Researchers also speculate that there is a link between insulin resistance and breast cancer. Normally the pancreas produces low levels of insulin to help metabolize glucose and carbohydrates.

Studies have shown that in overweight and obese people, the body tissues become less sensitive to insulin and these patients then have difficulty converting glucose into energy. The body then tries to compensate by making more insulin, stimulating the cells to divide more rapidly, much in the same way as estrogen. This rapid proliferation may increase the risk of cancer and might even work along with the excess estrogen in obese and overweight women to exert a particularly strong influence on breast cells, increasing a women's risk of developing breast cancer significantly.

Avoiding significant weight gain during adulthood may offer considerable protection against breast cancer, according to several studies. Regular physical activity is another preventive strategy as researchers have shown that a lifetime of regular exercise may decrease a person's total level of exposure to estrogen and other hormones.

Other Sources: American Institute for Cancer Research