The Truth Behind ‘Sugar Feeds Cancer’ Myth

Eat less sugar

People diagnosed with mesothelioma or another cancer may encounter myths and misconceptions about ingredients that worsen or improve their prognosis.

Sugar often tops the list of questionable substances.

But what’s the truth behind the “sugar feeds cancer” myth? Where did it come from? Does it have any real basis?

It’s important to understand what leads to these myths and misconceptions about cancer and get the facts.

What Is Sugar & How Is It Linked to Cancer?

In broad terms, sugar describes different types of carbohydrates — the main sources of energy in our diets.

Our bodies break down all carbohydrates into simple sugars such as glucose. When we eat foods rich in simple sugars, our blood sugar levels rise quickly, causing the pancreas to release the hormone insulin.

Insulin regulates the amount of glucose in our bodies. Studies on different types of cancers show tumor cells contain more insulin receptors than normal cells. Because insulin is a growth hormone, researchers believe elevated levels of insulin stimulate the growth of cancer cells.

Also, higher levels of sugar consumption lead to weight gain, diabetes and obesity, which may increase the risk of cancer.

The Mayo Clinic notes that PET scans may contribute to part of the cancer myth.

PET scans use a small amount of a glucose-based radioactive tracer. All body tissues “absorb some of this tracer, but tissues that are using more energy — including cancer cells — absorb greater amounts,” the Mayo Clinic site shows. “For this reason, some people have concluded that cancer cells grow faster on sugar. But this isn’t true.”

Moderating Sugar Consumption to Lower Insulin Levels

Because high insulin levels may lead to increased cancer cells, it’s important to avoid eating foods high in sugar.

But that’s easier said than done. Sugar is found in almost everything we eat: Candies, processed foods, dairy products whole grains, vegetables and fruit.

Moderating the amount of processed foods listing corn syrup or sugar as one of their first ingredients is one way of limiting sugar intake.

Complex carbohydrates, such as whole grains, rice, oats and beans, are rich in fiber, and they release sugar slowly during digestion, preventing surges in insulin.

Fiber, fat and protein also reduce sugar absorption. Roast chicken served with a side of vegetables and brown rice is great example of a complex meal.

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So What Should You Eat?

Avoid eating carbohydrates alone on an empty stomach because there is no protein, fat or soluble fiber to keep the sugars from speeding directly into the blood stream, causing a blood sugar spike.

For example, eat apple slices (carbohydrate) with a handful of nuts or a tablespoon of peanut butter (protein).

Read labels and avoid products with sugar as the first, second or third ingredient. Sugar may be disguised as corn sugar, corn syrup, glucose or dextrose.

  • Avoid sugary drinks such as sodas, sweetened coffees, bottled teas and shakes. Choose whole fruits over juices because the skins contain fiber.
  • Stay active. Exercise helps keep our blood glucose levels down, which in turn keeps our insulin levels in check.
  • Eat a balanced diet. Make sure two-thirds of your plate contains whole grains, vegetables, fruits or beans. The rest can be an animal protein (chicken or fish) or a vegetable protein such as tofu.

Try these food combinations:

  • Steel cut oats with fresh berries
  • Whole wheat crackers with peanut butter (no added sugar)
  • Apple slices with cheese
  • Unsweetened cereal, such as bran flakes, with milk
  • Small baked potato with grilled chicken or grilled fish and broccoli

The most important behavior for someone with cancer to remember is moderation when it comes to sugar consumption.

Enjoy your food.

Eating when we feel good is a true pleasure in life, and we shouldn’t be afraid to enjoy the foods we love. If you want a piece of cake, you should feel good about eating it, but eat a small slice and not on an empty stomach.

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Registered & Licensed Dietitian

Tejal Parekh is a registered and licensed dietitian in Florida with a master’s in nutrition and dietetics from Georgia State University. She realized her passion more than 10 years ago when she started working with cancer patients. Tejal also is one of the first dietitians in Florida to be board-certified as a specialist in oncology nutrition.

3 Cited Article Sources

The sources on all content featured in The Mesothelioma Center at include medical and scientific studies, peer-reviewed studies and other research documents from reputable organizations.

  1. The Academy of Nutrition and Dietetics. (2014, July). Sugar and Cancer.
    Retrieved from:
  2. American Institute for Cancer Research. (n.d.). The New American Plate.
    Retrieved from:
  3. Mayo Clinic. (n.d.). Diseases and Conditions: Cancer. Retrieved from:

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