GRACE :: Cancer Basics


Does Sugar Feed Cancer?

download as a pdf file Download PDF of this page

GRACE was fortunate enough to have Kelay Trentham, a nutritionist with a particular specialty as an Oncology Dietician who works at MultiCare Regional Cancer Center in Tacoma, WA, discuss several central questions about nutrition and cancer. Here are her comments. This is the first of a series of questions she discussed.

Every cell in our body uses glucose, which is the form of sugar that we distill all of our food down to for use as fuel, and cancer cells are not an exception to that. They use glucose for fuel just like other cells in our body, but one difference between a cancer cell and a normal cell is that cancer cells take up fuel at a much faster rate than normal cells. So that’s part of how they are just aberrant or abnormal cells, is that they take up nutrients, particularly glucose, at a much faster rate. You could compare it to RPMs on a car or if you were looking at your electric meter. The cancer cell’s electric meter just goes around quite a lot faster.

Simply eating sugar doesn’t promote cancer growth any more than eating anything else. I feel like this simplified concept – that sugar “feeds” cancer – that people see in the media or the internet, or sometimes in books and articles, is really not useful. Because our entire body’s primary fuel is glucose, and we need that to do all of our everyday activities.

Glucose is a sugar, and, again, lots of different kinds of foods are broken down into glucose. Things like your breads, your potatoes, peas, corn, etc. — all of those types of foods yield glucose during digestion — and then we use glucose for energy.

Now sugar may play an indirect role (in the development of cancer) if it’s eaten in excess. It can contribute to obesity. Sugar alone — refined sugar — is a concentrated source of calories, and when folks are overeating and putting on weight, we do know that obesity is a big risk factor for cancers. So excess sugar intake could contribute to the risk for cancer by contributing to obesity. But this doesn’t mean that eliminating sugar is necessarily going to reduce the rate at which cancer cells grow.

The best evidence so far, really, is that there is no direct link (between sugar and cancer). Carbohydrate is any type of sugar or starch, it’s our fuel; it’s what we use every day to keep us going.

Next: What is an “optimal diet” for someone with cancer?

12 Responses to Does Sugar Feed Cancer?

  • mikem says:

    Thank you this is the most clear, concise explanation I have heard on the subject. — mikem

  • Catharine says:

    Kelay –
    Thank you for the clear, concise information on this topic. I look forward to the next post on “optimal diet.”
    – Catharine

  • Portland Dave says:

    Hi, new poster here. I was diagnosed w/ Stage IV NSCLC adenocarncinoma in January. Just completed radiation & 6 rounds of carbo taxol chemotherapy. I feel like your statement is out-of-date given the recent study showing rampant tumor cell growth when cancer cells were fed high-fructose corn syrup. Also I suspect that a high glycemic diet could foster growth of IGF and thereby increase tumor growth. While there may not yet be solid evidence of the latter point, it seems prudent to minimize high glycemic index foods for cancer patients. I am following David Servan-Schreiber MD, PhD diet recommendations from his 2009 book Anticancer 2nd Ed. In reading your related post on optimal nutrition, it seems like we agree on what the best things are to eat, but with the prevalence of high-fructose corn syrup as the source of sugar in so many foods, that simply dismissing the nexus of sugar and cancer is not the most prudent or accurate advice. I welcome your response or the expert opinions of the oncologists on this site. Respectfully, Dave

  • Dr West
    Dr West says:

    I’ll try to see if Ms. Trentham can respond. I think the key is that the dietary recommendations are really whee we should converge, and that the issue is that questions like “Does Sugar Feed Cancer?” and the simplistic take-away answers people can come away with are just misleadingly binary. If the question were whether people should strive to avoid significant amounts of refined sugar or high fructose corn syrup, those of us who think the best answer to the “Does Sugar Feed Cancer?” is no would still agree on the desirability of a better diet. I don’t mean for it to sound like a cop-out to say that I think this becomes more semantic than real, but I do think that if we converge on the same practical recommendations either way, I’m not sure it really matters how we interpret an overly simplified question. I don’t think the answers are that simple.

  • Apra says:

    Sugar and cancer. I was also following David Servan’s book Anti Cancer but in the end did not find anything valuable in it. The things he recommends are good being a cancer patient himself, and I am sure if every patient can be as proactive as him it would help. But we see that most patients are laid back and do not have the strength to do heir own research or make their own food.
    Taking sugar or mild in tea or coffee or in breakfast cereals is ok I believe alongwith a little icecream from time to time.
    I am so happy to read this post by Dr. West and Ms. Trentham. It takes a load off my mind as my husband still loves fresh milk and some sugar.
    Organic is good but it is not very tasty at times and to get organic milk is very difficult in our place. Even the local milkman cannot be trusted because they feed their cattle on wheat bran coming from the large flour mills, so naturally there is pesticide in the feed.

  • FaithAndHope79 says:

    Ms. Trentham, Thank you. The explanation is clear and concise. Sometimes when my friends saw me sprinkle a little bit sugar in stir-fried vegetables, they jumped, “You still eat sugar?” which made me jump. Now I can tell them not to worry.

  • mehitabel says:

    I post on some of the inspire boards. I’m a lymphoma survivor and have studied nutrition and cancer for a few years.
    I believe this article is profoundly wrong, misleading and will only lead cancer sufferers away from the awareness of dietary changes that could indeed slow many cancers.

    The work of Dr. Thomas Seyfried has shown how ketogenic/calorie restricted diets slow and halt many cancers.
    It’s important to understand that, beyond driving mutation, when cancer becomes unwanted tissue mass it has a metabolism — and that metabolism is sensitive to blood glucose and derives easy energy from sugar.

    This author belies a misunderstanding of glucose metabolism in the body. Our body’s cells convert all food into ATP for cellular energy. The body makes ATP from sugar (carbohydrates) AND fat AND protein. Making ATP from sugar is called glycolyis — and, truth be told, it’s a dirty, inefficient, free-radical producing ATP regeneration system that is primitive beyond compare. It’s simple and goes way back in our evolution — that’s why cancer uses it. But, by comparison, burning fat — lipolysis — is wonderfully clean and efficient at creating ATP. The body prefers fat for fuel — it’s how the body evolved, when we never got cancer. But for doe-eyed nutritionists, the body “appears” to prefer sugar because it sees fat as benign and easily storable for later, but sugar is dangerous, inflammatory, very sticky, and must be dealt with immediately.

    Cancer fighters are somewhat faced with a question of “belief” when it comes to sugar. A small number, like me, believe that sugar is the devil — that it alone is capable of initiating, feeding, and accelerating cancer. Another much larger number of cancer fighters believe, bolstered by cancergrace, that sugar has almost no effect whatsoever on cancer and should in indulged in freely as long as you don’t get obese. And finally, many fighters are all about “moderation” and “balance.”

    I felt compelled to add a little balance to this article.

    all the best and good health,

  • aunttootsie001 says:

    What is to be said of the Alkaline affects on a active Cancer? This diet seems to be more Vegitarian diet. It looks like you can only eat Salmon or seafood and a lot of veggies?

  • catdander forum moderator
    catdander forum moderator says:

    I must comment here though I have no biology background and only speak as one who cares deeply about her husbands well being, and he has stage IV nsclc.
    My husband is a naturally very thin man who lost a lot a weight before dx and lost more weight after open surgery. His weight was a significant issue. The only things he would consume had high sugar content, including ensure that normally I’d not consider though he too ate a lot of desserts and fatty meats. I think if he’d not had the opportunity he’d not been able to stabilize enough to get the treatment that has allowed him to not only stabilize but after 3 years is NED and finally on a treatment break. He still eats a lot of sugar and is still about 10 lbs short of his normal 135.

    I just think I need to add my experience to Ron’s beliefs because I’d hate for a well meaning care giver to deny food to a person that may otherwise not be able to endure tested treatment because of a lack of strength and a belief that a person with cancer doesn’t have food options.


  • mehitabel says:

    Janine, I’m thrilled your hubby is NED — through surgery, treatment and, by your description, a fairly high-sugar diet. You indicated he’s thin, which might indicate he’s a good sugar “burner” and his body may have good insulin sensitivity. Also, we have all seen the daily miracle of the human body sustaining assault after assault…and surviving…maintaining.
    And, not all cancers are equally dependent on glycolysis at all stages.

    How many nsclc sufferers reach NED while overweight, diabetic, undergoing conventional treatment, and throwing back the sugary ensure’s?
    Answer: a surprising many.

    My strong desire is to offset the notion here that sugar is nutritive and nothing to worry about feeding your cancer.


    Please let me leave this link and a few quotes:

    “On October 10, 1998, my Mother passed away from lung cancer. She’d been diagnosed in June of that year… only two months after my father passed. I only wonder what might have been different had I known then what I know now. As she became more and more ill and more depleted from the chemotherapy and radiation, she was given more and more sugary treats to “help her keep her strength up”. She wasted away to skin and bones before our very eyes and we watched helpless, believing we were doing all we could.

    At the National Cancer Institute’s Government Website, they offer “helpful suggestions” on what can help a cancer patient who is not eating well, not being nourished, or not interested in food. Here are just some of their suggestions:

    Bread, muffins, and crackers
    Buttered popcorn
    Cakes and cookies
    Ice cream
    Frozen yogurt
    “Instant Breakfast” drinks
    Puddings and custards

    One of their cooking suggestions is: “Honey, Jam, and Sugar: Add to bread, cereal, milk drinks, and fruit and yogurt desserts. Use as a glaze for meats, such as chicken.” They go on to suggest you “Sandwich ice cream or frozen yogurt between cake slices, cookies, or graham crackers.”

    We took these suggestions. My mother starved to death. I may have learned all of this too late to help my own mother, but perhaps new awareness can help someone else’s…


  • Dr West
    Dr West says:

    I think it’s fair to acknowledge differing views, but I think that this question is one in which it becomes practically a religious argument, and there is little that can be said to change the views of the other side unless or until there is some actual clinical data to speak to the question. I agree that diet is relevant and am impressed by the striking associations of a Western diet heavily laden with animal fats is remarkably correlated with increases in the epidemiological risk of developing many cancers and feel that the prevalent US diet is contributory in our patterns of risk of cancer (as well as diabetes and heart disease). In fact, I recently switched to a vegetarian diet for health reasons (based on my own conclusions rather than a recommendation of my doctor).

    There may well be useful conclusions to draw from Dr. Seyfried’s work, but whatever that research offers, it isn’t strong clinical data on human cancer patients that shows better outcomes in patients who follow one diet over another. If these hypotheses are correct, they will still remain hypotheses until they are actually tested in clinical trials. Until then, both sides are operating more on faith-based perspectives that we can justify with scant, poor evidence to justify our own predispositions. I don’t think that the argument can or should be made that “sugar is terrific”, but rather that at this time, overall, there isn’t significant evidence that diet has a very significant effect on clinical outcomes in patients with known cancers. Absence of proof isn’t proof of absence, but I think it’s wrong for either side to take a dogmatic view here. It may well be fair to characterize sugar as the devil if we note that the devil is widely viewed as a faith-based religious construct.

    -Dr. West

  • mehitabel says:

    “…the conclusion is hard to avoid that sugar causes cancer…”
    Gary Taubes, “Is Sugar Toxic?”, New York Times Magazine, April 17, 2011

    “I have eliminated refined sugar from my diet and eat as little as I possibly can…”
    Craig Thompson, M.D., President, Memorial Sloan-Kettering Cancer Center, New York

    “Sugar scares me.”
    Lewis Cantley, Professor at Harvard Medical School and director of the Cancer Center at Beth Israel Deaconess Medical Center


    Dr. West, respectfully, I disagree with much of what you have stated. Doctors aren’t known for nutritional acumen and you may be contributing to that belief.

    You say — “There may well be useful conclusions to draw from Dr. Seyfried’s work, but whatever that research offers, it isn’t strong clinical data on human cancer patients that shows better outcomes in patients who follow one diet over another.”

    Does that mean you looked at it? Or are you dismissing it out of hand? Because it sorta proves exactly that…

    The ATP generation by glycolysis and lipolysis that I refered to, is NOT hypothesis, it’s NOT my personal “belief” — It truly is proven science. Cancer’s affinity for glycolytic pathways is proven science.

    “Malignant rapidly growing tumor cells typically have glycolytic rates that are up to 200 times higher than those of their normal tissues of origin.” (wiki)


    On your decision to become a plant-eater…i’m betting you believe in the lipid hypothesis of heart disease, too. I’m a double-bypass survivor and think Ancel Keys did us all a great disservice for which we will continue to pay dearly.

    You sound won over by Campbell and The China Study, and may be unaware of his legendary deceitfulness. The critique of his work by Denise Minger, and additionally by Dr. Chris Masterjohn and Dr. Michael Eades, is wonderfully strong, revealing science.

    Our biology can only be understood “in the light of evolution” as Theodosius Dobzhansky so knowingly put it in the title of his famous essay.
    We didn’t evolve as vegetarians. And while you may chose to live AS a vegan — your body will never BE vegan.
    Our first clear evidence of high incidence of cancer, heart disease, autoimmune diseases comes from the ancient agrarian egyptians — the first to grow wheat on the banks of the Nile and eat the perfect fruitsveggieswholegrainsleanmeat diet.
    When our ancestors were hunting the fatty cave bear and dozens of other huge animals to extinction — we didn’t get disease. There’s a world of science behind that. That’s not “hypothesis.”
    Weston Price was an anthropologic dentist, who traveled the world examining native tribes and their diets and physical health. He didn’t find one, single healthy vegetarian tribe.


    You do point out, as i did earlier, the religious and belief aspects of these dietary views.
    Even that is understandable in the light of evolution. It’s part of the “fight or flight” reflex — that whenever faced with an opposing view…we become more entrenched in our own.

    I find many cancer fighters simply split on the PET scan — many “get” that it’s simple proof cancer loves sugar — and many others don’t “get” it. They use a glucose analogue tracer — why don’t they use a roast beef analogue, or a fried egg analogue? — is it because they wouldn’t go to the cancer?

    The associations between sugar and cancer are very well documented.
    Cancer fighters should not be fed sweet lies that lead them away from valuable metabolic strategies.

    I won’t be persistent — I’ve had my say, thank you.
    The last link I put up has lots of very good science and cancer-fighting advice.

    all the best,

Leave a Reply

Ask Us, Q&A
Cancer Basics Expert Content


download as a pdf file Download PDF of this page

GRACE Cancer Video Library - Lung Cancer Videos




2015 Acquired Resistance in Lung Cancer Patient Forum Videos

download as a pdf file Download PDF of this page

Join the GRACE Faculty

Lung/Thoracic Cancer Blog
Breast Cancer Blog
Pancreatic Cancer Blog
Bladder Cancer Blog
Head/Neck Cancer Blog
Kidney Cancer Blog
download as a pdf file Download PDF of this page

Subscribe to the GRACEcast Podcast on iTunes

download as a pdf file Download PDF of this page

Email Newsletter icon, E-mail Newsletter icon, Email List icon, E-mail List icon

Subscribe to
   (Free Newsletter)

Other Resources

download as a pdf file Download PDF of this page

Biomedical Learning Institute