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Does Sugar Feed Cancer? Entry from Alexandra Rothwell, MPH, RD, CSO, CDN

Does Sugar Feed Cancer? Entry from Alexandra Rothwell, MPH, RD, CSO, CDN

As an oncology nutritionist, I meet with people throughout the stages of treatment,

recovery, and survivorship. The relationship between food and cancer is an ever-

developing and popular field, and because of this, the people I meet with tend to

have many questions. The following are a few of the most common questions I’m


Does sugar feed cancer?

This is a topic I’m asked about almost everyday, though, it’s often posed as a

statement, rather than a question.  The Internet is flooded with the concept that

sugar feeds cancer, and much of that information is not coming from reliable or

scientifically-based sources.   The answer to “does sugar feed cancer” is: yes… sort

of.  Sugar is the body’s preferred form of energy, and it “feeds”, not only malignant

cells, but every other cell in the body and is the only form of energy that fuels the

brain.  If sugar is not readily available, malignant cells can be sustained from the

byproducts of fat and muscle breakdown.  

There is, however, a likely connection between sugar and cancer, but the connection

is thought to lie in the way that sugar is metabolized - or processed - by the body.

 Alterations in sugar metabolism that involve insulin resistance lead to high levels of

insulin.  It’s high levels of insulin and another growth hormone, called IGF-1, that are

involved in the growth of cancer.  If this sounds confusing - it is - and the relationship

between insulin and cancer is not fully understood by the medical community at this


What this information boils down to, for you and me, is that for cancer, as with many

chronic diseases, it’s important to get to a healthy weight, exercise, and maintain

appropriate blood sugar levels through diet.  How do we do this?  Eating for optimal

blood sugar levels could be a post on its own, but the basics are: choose high quality

carbohydrates (i.e. the “whole” ones such as beans, whole grains, and vegetables)

and limit them, reasonably avoid refined sugars, particularly sugar-sweetened

beverages, and consume carbohydrates as part of meals that contain fiber and fat,

both of which can slow the release of sugar into the bloodstream.

Alexandra Rothwell, MPH, RD, CSO, CDN

Alexandra Rothwell is registered dietitian, with a specialization in oncology nutrition.

She currently works at Mount Sinai’s Dubin Breast Center, in New York City,

primarily consulting with breast cancer patients throughout treatment and

survivorship. Previously, she worked with patients of head and neck cancer, bone

marrow transplant, gastric, colon, and prostate cancer, among other malignancies.

She has completed her Masters of Public Health from Mount Sinai’s Ichan School of

Medicine and received her nutrition education from New York University.

2 Replies

Everything I have read says the body will use the sugar first which is why following a low sugar diet rather than a low fat one will encourage the body to lose weight as it will use up the sugar reserves quickly and then move onto the fat reserves.


I am on the 6th week of a six week free online course given by Bath University. Have learned a lot on cancer! Cancer can develop for any reason but food intake and environment we live can be responsible for cancer. Why sugar, it can be any food!

Post gives interesting reading.

If we understand why the cells in our body decide to go in a different way and develop cancer then the researcher may or can find answers, more needs to be done.

Man made food and environment has a lot to do with what is happening to our body.

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