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Home  /  Integrative Cancer Care  /  Body  /  Cancer Diet  /  Foods to Avoid  /  Sugar and Cancer

Sugar and Cancer

By Jeannine Walston

Sugar is a crystalline carbohydrate used as a sweetener and preservative. The main types of sugar include sucrose, fructose, glucose, and lactose.

What is the relationship between sugar and cancer?

Research indicates a strong connection between sugar and cancer, especially survival of cancer cells.

“Over seven decades ago, classical biochemical studies showed that tumors have altered metabolic profiles and display high rates of glucose uptake and glycolysis. Although these metabolic changes are not the fundamental defects that cause cancer, they might confer a common advantage on many different types of cancers, which allows the cells to survive and invade. Recent molecular studies have revealed that several of the multiple genetic alterations that cause tumor development directly affect glycolysis, the cellular response to hypoxia and the ability of tumor cells to recruit new blood vessels1.”
-Chi Dang, MD, PhD, Johns Hopkins School of Medicine

The link between sugar and cancer is further explained with information about how sugar feeds cancer cells with emphasis on cancer development and cancer proliferation spreading through cancer metastases.

“Compared with normal cells, cancer cells have a sweet tooth: they consume between ten and fifty times more glucose than surrounding healthy cells… PET scans, which detect glucose consumption, have shown that the higher the rate of glucose accumulation in cancer cells, the more aggressive the tumor—that is, the more invasive and likely to metastasize it is… The more rapid their proliferation, the more glucose cancer cells consume… These and many similar findings suggest that controlling your blood sugar can make a substantial difference in controlling the course of your cancer. What raises blood sugar? The chief dietary culprits are refined carbohydrates.”
-Keith Block, MD, Life Over Cancer

What do these scientific findings mean about sugar and cancer?

  • Tumors absorb sugar at high rates. They are sugar junkies and studies have demonstrated this fact for almost 100 years.
  • Sugar appears to provide cancer cells an advantage to survive and spread.
  • Sugar supports the formation of new blood vessels involved in cancer growth.
  • Cancer cells with high amounts of sugar are more likely to metastasize.
  • Studies indicate that sugar reduction and sugar elimination contribute to cancer prevention and cancer survival.
  • Dietary changes with knowledge about the link between sugar and cancer can support health and healing in people with cancer.
  • Foods with low glucose levels maintain healthy blood sugar levels and support an anticancer environment.

What are the most prevalent sugar sources?

White Sugar

White Sugar

Foods may contain processed sugar additives or natural forms of sugar. Sugar sources include white or brown sugar, artificial sweeteners such as splenda or aspartame, corn syrup, high fructose corn syrup, rapadura, honey, syrups such as maple, fructose, and dextrose, and others.

What foods contain sugars?

Most processed foods contain sugar, including anything with white flour, soft drinks, table sugars, baked goods, fruit drinks, dairy desserts, candy, breakfast cereals, and teas. Some foods in their natural form contain sugars, and foods high on the glycemic index contain higher amounts of sugar. Some high glycemic foods include melons, apricot, kiwi, tropical fruits, dates, figs, raisins, grapes, cooked parsnips, rutabaga, pumpkin and squash, beet, white potato, white pasta, white bread, chips, candy, ice cream, and many other foods.

What are refined carbohydrates?

Refined carbohydrates provide calories without vitamins, minerals, and fiber.

What foods contain refined carbohydrates?

White sugar, honey, high-fructose corn syrup, cookies, cakes, pastries, white bread, crackers, potato chips, fries, commercial waffles, candy, donuts, and many dry breakfast cereals contain high levels of refined carbohydrates.

What is the glycemic index?

The glycemic index refers to a number associated with the conversion rate of carbohydrates to blood glucose levels in the body. Ratings lower on the glycemic index are associated with less sugar, and ratings high on the glycemic index are associated with rapidly rising blood glucose levels.

What are the health effects of high glycemic foods?

“The body immediately releases a dose of insulin to enable the glucose to enter cells. The secretion of insulin is accompanied by the release of another molecule, called IGF (insulinlike growth factor), whose role is to stimulate cell growth. In short, sugar nourishes tissues and makes them grow faster. Furthermore, insulin and IGF have another effect in common: They promote the factors of inflammation, which… also stimulate cell growth and act, in turn, as fertilizer for tumors. Today we know that the peaks of insulin and the secretion of IGF directly stimulate not only the growth of cancer cells but also their capacity to invade neighboring tissues.”
-David Servan-Schreiber, MD, PhD, Anticancer

What are other potential health effects from sugar?

  • Creates acidity
  • Uses the body’s store of vitamins and minerals without providing any in return
  • Contributes to mental disorders
  • Reacts with proteins and forms little crusts or plaques called AGEs (advanced glycation end production)

What else should I know about sugar?

  • The average American eats over 158 pounds of sugar annually, or about 50 teaspoons daily2.
  • Sugar consumption in the United States increased by 30 percent from 1983 to 19993.

High Fructose Corn Syrup

High fructose corn syrup is made by processing cornstarch to fructose and then adding it to pure corn syrup.

What foods contain high fructose corn syrup?

High fructose corn syrup is found in many canned foods, soft drinks, cookies, salad dressings, condiments, yogurts, soups, and other foods. It is hard to find packaged processed foods in most grocery stores without high fructose corn syrup.

What are potential health effects from high fructose corn syrup?

  • Promotes obesity4
  • Increases appetite by altering metabolism
  • Increases caloric consumption
  • Induces insulin resistance
  • Linked to type 2 diabetes, high blood pressure, and coronary heart disease5
  • Intense sweetness can surpass cocaine addictive reward6
  • Stresses the liver that responds by producing inflammatory compounds

What else should I know about high fructose corn syrup?

  • In the 1980s, high fructose corn syrup became widely introduced into the food supply. This is in part due to corn subsidies to the corn industry from the United States government and taxes on sugar imports.
  • High fructose corn syrup is the current sweetener of choice in the United States food supply and creeping into other parts of the world, but not Europe that continues to use sugar and only small amounts of high fructose corn syrup.
  • Today, the United States makes over 17.5 billion pounds and on average, each person consumes 66 pounds annually, and 12 teaspoons daily7.
  • Mercury has been detected in some products rich in high fructose corn syrup.
  • Some high fructose corn syrup is made with genetically modified corn.
  • Some people have allergies to corn and should avoid high fructose corn syrup for that reason as well.
1. Dang CV, Semenza GL. Oncogenic alterations of metabolism. Trends Biochem Sci. 1999 Feb;24(2):68-72. Review. PubMed PMID: 10098401
2. U.S. Department of Agriculture data
3. U.S. Department of Agriculture data
4. Bray GA, Nielsen SJ, Popkin BM. Consumption of high-fructose corn syrup in beverages may play a role in the epidemic of obesity. Am J Clin Nutr. 2004 Apr;79(4):537-43. Review. Erratum in: Am J Clin Nutr. 2004 Oct;80(4):1090. PubMed PMID: 15051594
5. Stanhope KL, Havel PJ. Endocrine and metabolic effects of consuming beverages sweetened with fructose, glucose, sucrose, or high-fructose corn syrup. Am J Clin Nutr. 2008 Dec;88(6):1733S-1737S. Review. PubMed PMID: 19064538
6. Lenoir, M. et al. 2007. Intense sweetness surpasses cocaine reward. PLoS ONE 2 (1):e698.
7. U.S. Department of Agriculture data