“As Americans' collective waistline has continued to expand, so has the prevalence of obesity-related cancer. According to the June issue of Mayo Clinic Health Letter, an estimated 14 percent of cancer deaths in older men and 20 percent in older women can be attributed to excess body fat. It's not fully understood why excess body fat increases the risk of cancer.
• Insulin -- Obesity and inactivity generally lead to higher levels of insulin circulating in the blood.
• Estrogen -- Adding to insulin's influence on estrogen levels, fat tissue also produces this hormone.
• Immune system -- Excess fat is thought to release proteins that may suppress the immune system and increase inflammation.
Although there's evidence that gaining weight increases the risk of cancer, there has been almost no research that demonstrates whether losing weight will reduce that risk. Two major components of weight loss -- a healthy diet and exercise -- appear to be excellent ways to reduce cancer risk.”