Sugar and cancer

Last Modified: February 9, 2003

Dear OncoLink "Ask The Experts,"
Does cancer feed off sugars in the body? In other words does sugar make the cancer grow faster?

Katrina Claghorn, MS, RD, Registered Dietitian at the Abramson Cancer Center of the University of Pennsylvania, responds:

There has been increasing interest about the impact of sugar on cancer. Recent studies suggest that a diet high in simple sugar may increase the risk of developing cancer. While the association has been noted, we are still unsure of the cause. Is it that a diet high in simple sugar is usually deficient in cancer fighting nutrients, or that simple sugar causes a surge in insulin which increases insulin like growth factor (IGF)? Despite the lack of solid research quite a number of books and web-sites advise eliminating sugar as part of a cancer prevention diet.

Should you avoid sugar and all carbohydrates? Our bodies need glucose for energy and will make glucose from fat and protein if there is not enough glucose available. Should you avoid simple sugars? The answer to this is a little more complicated. All carbohydrates eventually break down to simple sugars. However, it has been suggested that elevated insulin levels may increase cell growth, which may promote proliferation of cancer cells. The way to prevent surges in insulin levels is by reducing your intake of foods that are very high in simple sugar, such as sweets and sodas, or by combining simple sugars with foods that have fiber, protein and fat which slow their absorption. It would be unhealthy to avoid all food sources of simple sugars since this would include fruits, vegetables and grains. These foods are the prime source of nutrients and compounds that have been shown to reduce cancer risk.

Based on research the American Cancer Society issues the following recommendations concerning the inclusion of carbohydrates in the diet to reduce cancer risk:

Eating 5 or more servings of a variety of vegetables and fruits each day.
Eat other foods from plant sources several times each day
Limit the amount of refined carbohydrates, including pastries, sweetened cereals, soft drinks, and sugar you eat.