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Does Sugar Feed Cancer?

This question is common among people impacted by cancer. The internet is flooded with cancer-related nutrition information. It can be difficult to decide what claims are based in fact and which are fiction. This article aims to address some of the common misconceptions around sugar and cancer. Remember, the best source for any nutrition related information is a registered dietitian.

Sugar “feeds” ALL of the cells in the body, NOT cancer cells alone.

  • All carbohydrates are converted into a form of sugar (glucose specifically) by the body before it can used by cells.
  • Glucose does not “feed” cancer cells any differently than healthy cells.
  • It is not possible to “starve” cancer by not eating sugar.

The presence of cancer in the body changes the way our body digests carbohydrates and affects glucose production.

  • Tumors are capable of causing the body to produce more glucose.
  • Cancer may cause the body to break down fat and protein, causing carbohydrate metabolism to change.
  • The healthy cells in the body become more resistant to insulin, the hormone that helps glucose get into the cells.

Although sugar does not “feed” cancer, it is still a good idea to limit sugar in your diet as it provides very little nutritional value.

The following are some tips for making sure you are eating a nutritious diet:

Choose complex carbohydrates instead of sweets and sugar sweetened drinks.

  • The body needs nutritious food during cancer treatment. Choose foods that provide the body with nutrients, not only sugar.
  • Examples of complex carbohydrates include fruits and vegetables and whole-grain breads, cereals, rice, and pastas. Beans such as kidney, pinto, and black beans are all excellent sources of protein and complex carbohydrates.

Eat consistently and regularly to keep blood sugar level stable.

  • Eat small meals every 2-3 hours including a source of lean protein, complex carbohydrate, and healthy fat.
  • Here are some examples of healthy mini meals:
    • ½ of a sandwich made from a slice of 100% whole-wheat bread, 2 tsp. peanut butter, 1 tsp. fruit preserves
    • 1/2c. cottage cheese and ½ c. canned fruit in 100% juice
    • 1/4c. black beans, 1/2c. brown rice, 1 Tbsp. salsa

Beware of becoming obsessed with food, ingredient lists, etc. Try to relax and set realistic food goals.

  • Refrain from searching the internet too much for nutrition information related to cancer. It is best to consult a registered dietitian who specializes in oncology.
  • Try to enjoy eating and the social activities that are associated with it.
  • Be selective of the advice you are given from other people. A lot of unsolicited nutrition advice is given in the midst of a cancer diagnosis.
  • It is important to remain flexible in your diet. If you are having a lot of nutrition related side effects and weight loss, you may be encouraged to eat a more liberalized diet.

For more tips on reducing your sugar intake and eating a healthier diet, read Guidelines for Reducing Sugar Intake.