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Environmental Health

Weight, Obesity & Cancer: A Serious Risk

Obesity is a serious health condition.  The modern environment makes it hard to keep a healthy weight.  You may have heard that cancer can be related to genes and environmental exposure (such as excess sun and skin cancer).  Did you know that excess weight also increases your risk of cancer?  Cancer is a serious health condition faced by many Americans.

Cancer Risk Factors:

Extra weight seems like it is just the body’s storage site for fat.  But fat has an active role inside your body.  Being overweight or obese can put you at risk for health conditions such as heart disease and stroke.  Experts are learning that being overweight or obese can also put you at risk for cancer.  Research shows clear links between being overweight or obese and cancers such as:

Research also suggests that being overweight or obese may increase the risk of developing cancers such as:

The good news is that because of this connection we can make healthier choices to reduce our risk of developing these cancers!

How Does Fat Cause Cancer? - A Look inside Our Bodies

What Are Hormones? – Hormones are chemicals that travel throughout the body and trigger changes.  Fat produces certain hormones.  These hormones interrupt the way our bodies normally store and process the food we eat.  The hormone leptin increases your appetite, and causes you to eat more.  Other hormones released by fat cause you to increase the amount of energy your body stores as fat, and changes where the body stores fat.  Fat around your stomach is the most serious.  Fat in this area puts you at a higher risk of developing cancer.  

A Look at Estrogen

Estrogen is normally produced by certain cells in our bodies.  However, fat releases extra estrogen.  This increases the total amount of estrogen in our bodies.  This extra estrogen, along with other chemical changes, creates an unstable state.  Some cells can go off course, and are no longer controlled like normal cells. Without this control, they can now become cancer.  The cell now has a mutation in its DNA code.  As it reproduces, it passes the mutation on to each new cell.  These cells grow and divide quickly.  This creates larger and larger numbers of cancer cells.

A Look at Insulin

Insulin is the hormone that helps each cell in our body use the food we eat.  The form of food our cells can use is glucose.  Glucose comes from many different kinds of foods like bread, potatoes, and fruit.  Extra weight causes cells to become resistant to insulin.   In the state of obesity or overweight, the body release more insulin In order to normalize high glucose levels.  This condition is known as insulin resistance.

High insulin levels increase cell growth and cell division.  This puts your body in a cancer sensitive state.  In this state, your DNA is more likely to develop a mutation.  When a mutation occurs, it changes your normal cell blueprint and causes the cell to turn into cancer.  Suddenly, the cell reproduces with this new mutation.  All cells that come from the mutated cell have this cancer blueprint. They begin growing uncontrollably.

Research suggests that maintaining a healthy weight is associated with a lower risk of cancer and a lower risk of cancer recurrence (when cancer comes back after treatment) in cancer survivors.  You can prevent or delay the development of cancer by living a healthier life.  Eat healthy, make time to get enough sleep and physical activity every day and do not smoke. Start small, set goals to make healthier changes in your lifestyle.  Aim to balance the calories you eat with the physical activity you perform each day.  If you need to lose weight, remember every pound makes a huge difference in your health.  Keep your goal in mind and don’t give up!

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Last Reviewed: Jul 27, 2015

Li  Li, MD PhD Li Li, MD PhD
Case Western Reserve University