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Does sugar 'feed' cancer cells?

Turns out sugar doesn't 'feed' cancer cells -- it's actually vital to cell function.
Turns out sugar doesn't 'feed' cancer cells -- it's actually vital to cell function.
Maksym Kravtsov/ThinkStock

Although the shock of receiving a cancer diagnosis had yet to wear off, Judy was beginning to come to terms with it. She started to change her lifestyle by eliminating all types of sugar from her diet, even though it meant cutting out fruit and breads. By the time Judy arrived at her first appointment with a cancer specialist, she had been sugar-free for two weeks -- and was completely unprepared to hear what her doctor had to say.

Turns out, sugar doesn't "feed" cancer cells. Instead of cutting out all sugars, Judy should have been including beneficial foods in her diet, including fruits and whole grain breads. She was already a healthy weight, said her doctor, and should concentrate on overall nutrition, especially in light of the chemotherapy she was about to endure.

Sugar is vital to cell function. Glucose (sugar) is essential for cell growth and keeping vital organs functioning normally, and, as of 2015, there's not yet any evidence that giving up sugar keeps cancer cells from dividing and multiplying. In fact, without the ability to use glucose as fuel, cells take fuel from other sources, leading to malnutrition and muscle loss.

While it's true that cancer cells use more glucose than healthy cells, and convert the glucose into energy used for cell replication, the sugar doesn't necessarily make them grow more rapidly. Emerging research, however, suggests that researchers may someday make a cancer cell's penchant for sugar work against it. By inserting an enzyme to short-circuit cancer cell's access to glucose and related energy sources, it may slow or stop a cancer cell's ability to grow [source: Le et al.].

There's evidence that eating excess sugar contributes to obesity and is indirectly linked to an increased risk in cancer, such as breast, colorectal, pancreatic and prostate. According to the American Heart Association, men should ingest no more than 9 teaspoons of sugar a day and women should take in no more than 6 teaspoons of sugar. These amounts equal 150 calories and 100 calories, respectively, and most people easily take in twice that amount on any given day. Even if you cut out the common culprits, like sodas and cakes, sugar is still present in sauces, salad dressings and canned vegetables. Often, sugar is listed on the label under a different name, such as fructose, lactose, sucrose, maltose, glucose or dextrose, making it more difficult to detect [source: CTCA].