Obesity and Cancer Risk

Obesity has been shown to lead to an increased risk for many types of cancer. Several possible explanations for this association have been proposed, including:

• Excess amounts of estrogen are produced from fat tissue. When high levels of estrogen are present, they can be linked with an increased risk of breast, endometrial, and other cancers.
• Obesity often produces an increase in levels of insulin and insulin-like growth factor-1, called IGF-1, in the blood. This increased production may result in the development of certain tumors.
• Adipokines are hormones that affect cell growth. Because they are produced by fat cells, this abnormal cell growth is more common in obese people.
• Tumor growth regulators in the body are possibly affected, both directly and indirectly, by fat cells. This can increase the risk of tumors.
• Chronic low-level inflammation, which has been linked to increased cancer risk, is often found in obese people, and
• Immune responses, effects on the nuclear factor kappa beta system, and oxidative stress are mechanisms that may be affected by obesity, and can increase cancer risk.