20 links between sugar and cancer

20 links between sugar and cancer

There are very clear links - both direct and indirect - between sugar and cancer; blood sugar levels have been linked directly to cancer risk and cancer growth; and higher blood sugar levels cause chronic inflammation, damage the immune system and the microbiome, all factors known to promote cancer; Review.

Sugar promotes cancer - directly and indirectly

There's a common and self-perpetuating Medical Myth that 'there is no evidence that sugar feeds cancer cells'. Have you ever heard a Doctor, oncologist or nurse say that?  Or even, "But all cells use sugar"; or "You need sugar to be healthy"? Far from it - consuming sugar is definitely NOT good for your health!

   i) The Truth is that all cells can USE sugar as a fuel, but not to anything like the extent most cancer cells do (although some cancers such as pancreatic and prostate cancer cells can sometimes be an exception).. Most cancer cells GORGE on sugar. They have many times more insulin receptors on their surface and different metabolic proteins within them, and these stuff sugar into the cancer cells and burn it! That's why these biochemical changes are there!

   ii) Healthy cells don't NEED sugar; but cancer cells do need it. Healthy cells can burn ketones from fat; cancer cells cannot. If there's no sugar consumed (for example during fasting), blood sugar levels plummet and the body starts to break down fat. Healthy cells can burn this instead of sugar, cancer cells cannot. Cancer cells need their sugar fix.

   iii) Where's the research? Have you ever noticed how many articles there are on the Internet saying that 'sugar feeding cancer is a myth', often refocusing you quickly onto a different thought such as obesity? How many of these anti-sugar-and-cancer articles carry a single major research reference?

   iv) Sugar also severely damages the immune system. A little glucose is used by a healthy immune system; but high blood sugar levels damage it, causing pro-inflammatory cytokines to form (1). Sugar (the equivalent of drinking two cans of fizzy soft drink) also damages phagocytosis (surrounding and neutralising rogue cells, viruses and pathogens). And with higher blood sugar, your neutrophil numbers stay the same, but their ability and effectiveness to attack cancer cells declines (7). Finally, high blood sugar level damages your innate immune system so that you cannot deal with viruses and pathogens and other rogue cells like  ... cancer cells (2, 3).

Scientific American even ran a  headline stating that 'EATING SUGAR MAY PUT YOUR IMMUNE SYSTEM INTO A TEMPORARY COMA". Yes, really - a temporary coma!.  

v) Sugar damages the microbiome High blood sugar is linked to a greater risk of autoimmune disease (4), and autoimmune disease (e.g. Hashimoto's, Fibromyalgia, Chronic Fatigue Syndrome) starts in the gut. According to Columbia Medical School researchers, high blood sugar sets off a chain-reaction damaging your gut microbiome membership, causing metabolic syndrome and leading to an increased risk of disease (5).

We also know that a decline in the microbiome promotes.  .... cancer, for example, pancreatic (12). And University of Virginia researchers have shown that an unhealthy microbiome causes breast cancer and then the unhealthy microbiome increases mast cell infiltration into breast tumour tissue and this drives metastases (13). Finally, sugar consumption negatively alters the delicate balance between anti-inflammatory gut bacteria, and pro-inflammatory ones. Yup, sugar causes more problems and inflammation in the gut and then the body (14), which can result in .... cancer

None of the 'Sugar and cancer myth' articles even mention these inconvenient and damaging truths.

Instead, Cancer patients are regularly offered sticky buns, chocolate cake, biscuits and milky sugary tea by hospitals or charities such as Cancer Research and Macmillan Cancer Support when they are fundraising. Do they understand they are damaging the person's immune system and their microbiome and quite probably causing, at minimum, a temporary halt on the person's ability to attack their cancer? 

You can also have these delicacies when you have your IV chemo. Some anti-cancer drugs are given intravenously with sugar in your drip bag; some drugs are even stored in sugar. Most chemotherapy combinations are given with the steroid Dexamethasone. It has an unfortunate side-effect. Dexamethasone is known to raise your blood sugar significantly!

And so it goes on. Non-science everywhere. 

"It is incredibly easy to find quality research evidence that consuming glucose, poor immune systems, poor microbiomes and cancer progression are linked, either directly or indirectly. Lots of it. If you want to have a healthy microbiome, a great immune system and try to beat cancer, avoid  sugar and 'empty calories'. It's a good place to start". (Chris Woollams; Oxford University Biochemist; Founder CANCERactive).

* * * * * 

20 direct links between sugar and cancer - from research

1. In the January 2014 Journal of Clinical Investigation (124 (1), 367 – 384), scientists Yasuhito Onodera, Jin Min Nam and Min J Bissel showed that increased glucose uptake actually promotes cancer via two pathways – EPAC/RAP1 and O-GicNAc. They showed that increased glycolysis (due to increased use of glucose as a fuel) actually caused cancer to form. Cancer cells operate this fermentation-type process. The Mayo Clinic states clearly on its website that, "There is some evidence that CONSUMING LARGE AMOUNTS OF SUGAR IS ASSOCIATED WITH AN INCREASED RISK OF CERTAIN CANCERS". 

2. Dr. Craig Thompson, President and Chief Executive of Memorial Sloan Kettering Cancer Center has shown that a gene, AKT, promotes cancer by signaling what a cancer cell should ‘eat’ in about 80 per cent of cancers. “When an AKT protein is placed inside a cell, it does what any single-cell organism would do - IT JUST STUFFS ITSELF WITH GLUCOSE and makes as many copies of itself as possible”. Thompson has actually caused cancer in this way in his experiments. Dr. Chi Van Dang, Director of the Abramson Cancer Center in Pennsylvania goes further. He says that cancer cells are “addicted to nutrients ... like glucose” and notes that when they cannot consume enough, they just wither and die.

3. At Weill Cornell Medicine, Professor Dr. Lewis Cantley leads a team that has been researching the links between sugar, insulin and cancer for a good number of years. One study alone showed that drinking the equivalent of one can of fizzy soft drink a day made colorectal cancer tumours grow much faster. He even knows why. It's all to do with the P13K gene which is turned on by insulin and stuffs cancer cells full of sugar, if there's sugar in the blood stream. And, wait for this .... Pharmaceutical firms have even been trying to develop drugs to stop this!

4. Johan Thevelein, a microbiologist, and a team at Vrije University in Brussels have shown that a derivative compound from common sugar (fructose-1,6-bisphosphate), acts as a direct activator of the ras gene, which makes a protein causing cells to grow aggressively and out of control in cancer. This in turn stimulates the formation of more fructose-1,6-biphosphate so setting in a 'self-feeding downward spiral'.

5. American Medical School Johns Hopkins has researched colorectal cancer and sugar - Colon Cancer may yield to cellular sugar starvation (6). They showed that starving patients of sugar increases survival, finding two genes that cause a cancer’s survival and growth in situations where healthy cells fail.  One of the cancer genes, GLUT1, makes more glucose transporters and helps the cells at the centre of a tumour digest more glucose. Poor sugar control has been consistently linked with cancer and people with Type-2 diabetes have a higher risk of cancer of colorectal cancer; this may be direct through glucose, or indirect through insulin, according to the American Academy of Oncology Nutrition.

6. The University of Minnesota, in a 2013 study, showed that post-menopausal soda-drinking women had a higher risk of type 1 endometrial cancer. This sugar consumption link was independent of any obesity issues.

7. High blood sugar levels are linked to higher cancer risk and lowered survival. As long ago as 1985, researchers, using mice, studied three identical groups, each having been given breast cancer. 70-day survival was inversely proportional to sugar consumption. The lower the blood sugar the greater the survival (8).

8. Scientists at University College, London conducted research where they 'resensitied' their MRI machines. No longer did they need to use a radioactive dye bound to the sugar. They could just give the patient sugar equivalent to half a small bar of chocolate. Their MRI scans identified tumours simply from their high consumption of sugar. To quote Dr. Simon Walker-Samuel, "The new technique called glucoCEST (glucose chemical exchange saturation transfer) is BASED ON THE FACT THAT TUMOURS CONSUME MUCH MORE GLUCOSE (a type of sugar) than normal healthy tissues in order to sustain their growth".  MRIs have always used a cancer's sugar lust to work. Oncologists know this.

9. If cancer cells cannot find glucose to grow and survive, sometimes they turn to glutamate as an alternative fuel. If this is not true, then Elena S. Reckzeh would not have found that by using a glucose inhibitor Glutor, and following it up with an inhibitor for glutamate (CB-839) SHE STOPPED CANCER GROWTH - it withered and died! Interestingly, Glutor had no effect on healthy cells because, as Biochemists know, they have a different and more efficient way of metabolising glucose.

10. This was not the first time that inhibiting glucose uptake has been shown to block cancer cell development. Researchers from the Biochemistry Dept. of Oxford University used a sugar extract from avocados (mannoheptulose); this inhibited glucose uptake by between 25 and 75% (Board M; Can Res, Aug 1995; 55(15) 3278-85). Laboratory animals, given this mannoheptulose sugar for 5 days, showed tumour reductions of 65-79%.

11. Researchers at the Colorado Cancer Center led by Dr. Craig Jordan have shown that not only do leukemia cells contain more glucose receptors to help them grow, they actually block their healthy neighbours ability to uptake sugar, so there is more available for the cancer. They even target the 'happy hormone' serotonin, which causes lowered insulin and MORE glucose availability in the blood stream, ensuring their growth!

12. The glucose and cancer risk equation is not a direct straight-line relationship. Some cancers - for example, glioblastomas and astrocytomas - seem to be more dependent on glucose. (See ‘Gliomas are driven by glycolysis – S. Oudard, E. Boilier et al; Anticancer Research 17; pg. 1903-1911’.)  Even within a cancer type, not every person's cancer reacts the same way to glucose. This has been explained by Duke Medical School who note that an enzyme, GAPDH, specifically controls the rate of glucose burning in a cancer cell and cancer aggression is determined by levels of GAPDH present. 

But there's a second non-linear effect - cutting blood glucose (for example in Time Restricted Fasting) reduces insulin levels and this in turn reduces inflammation in the body (because insulin is a proven driver of the Cox-2 inflammation pathway). Cancers love inflammation; it helps them spread.  In 2010, Yale Medical School Professor, Tian Xu, showed Cox-2 inflammation also turned on two cancer-causing genes.

13. Put that can of Coca Cola down!!! There is evidence that High Fructose Corn Syrup (HFCS, the standard sweetening ingredient in most fizzy soft drinks) is actually worse than glucose. In 2010 research conducted by Dr Anthony Hearney of UCLA's Jonnson Cancer Center, showed that pancreatic cancers use the sugar fructose, very common in the Western diet, to activate a key cellular pathway that drives cell division, helping the cancer grow MUCH more quickly! Hearney stated in the report that "Although it is widely known that cancers use sugar to fuel their growth" ... the team concluded that not all sugars were equal, and that glucose and HFCS made cancer cells react quite differently; HFCS being worse (11).

14. Put that shop-bought fruit juice or smoothie down!!! As long ago as 1973 research showed that added sugar consumption could block the action of the immune system from attacking cancer cells (7), The study from Loma Linda University showed that drinking sugar in this way could 'cripple' your immune system for up to five hours.

15. Even your daily healthy fruit smoothie may not be so healthy! I100,000 person study across a 5-year period by French Health Agencies, consuming a daily home made fresh fruit juice (10.3 gm sugar per 100 ml) or a fizzy soft drink or a purchased 'healthy' juice or smoothie (both 10.9 gm sugar per 100 ml) were linked to an 18% increased risk of any cancer, and a 22% risk of breast cancer. The research was reported in the British Medical Journal in 2019. A daily diet drink caused no such increase - but see here. Yes, even a home made fruit smoothie gives you a big sugar 'hit'.

16. A report (Oct 16th, 2014) in the American Journal of Public Health (9) showed that consuming sugary drinks drastically depresses the immune system and importantly could damage your essential DNA telomeres MORE THAN SMOKING!!! It concludes that ‘short telomeres have been associated with the development of the chronic illnesses of aging, including heart disease, diabetes and cancer’.

17. Researchers from the Center for Vascular Research, Daejeon, South Korea have found that while cancer cells burn glucose in the primary tumour, when they move to the lymph nodes there is a 'switch'  triggered by a protein 'YAP' that turns them from feeding on glucose, instead to using fatty acids. They concluded that "the primary cancer tumour uses sugar to grow"...  but the spread of cancer is more linked to fat. 

18. Intermittent fasting can help - two day, or three to five day fasts have been shown by experts such as Professor Dr. Valter Longo, of  the University of Southern California, San Diego, to boost the immune system while stopping the progression of cancer by suppressing blood glucose, insulin and growth hormone levels. In animal studies, short-term fasting alone delayed tumour growth to the same extent as treatment with the drug cyclophosphamide. Indeed, there are numerous studies on how cutting blood glucose levels and fasting makes chemotherapy work better while protecting healthy cells (10).

19. The Oncologist journal in the UK in 2012 featured an editorial from an expert Detroit oncologist Andrew Turrisi, commenting on research showing that using calorie restriction (cutting carbohydrate calories by 15%) ‘made radiotherapy work better’ in patients.  Similar results have been found for chemotherapy (Nutrition Research and Radiation – When less is more). Full human Clinical Trials are underway.

20. A meta-analysis of 20 research papers by Dr. Ming Yin et al in the Oncologist (November 15th 2013) stated the sugar-lowering diabetes drug Metformin helped ‘increase survival times of patients’. Editor Bruce Chabner said that the use of metformin “could actually play a part in tumour reduction by helping to lower plasma glucose levels”. Why is that important if glucose doesn't help drive cancer?? Restricting blood glucose can make cancer treatments work better, improving drug performance and increasing survival. For example,  high-dose Metformin can increase the anti-tumour effects of Temozolomide with brain tumours, while the herb Berberine enhances the AMPK pathway and Docetaxel sensitivity increasing its effect with breast cancer and prostate cancer. And it's not just with chemotherapy. A study from Oxford University showed that the anti-cancer effect of Oncolytic Viruses was improved ... if you restricted blood sugar. 

Professor Len Seymour, Chair of Gene Medicine at Oxford said that 'BECAUSE CANCER GOBBLES UP SUGAR SO QUICKLY, the cells are more vulnerable to attack if you restrict the glucose.

Are these top scientists all wrong?

Go to: Give up sugar for just 10 days - feel the difference  



1. Harmful effects of high amounts of glucose on the immune system: An updated review; Navid Shomali et al; Biotechnol Appl Biochem
. 2021 Apr;68(2):404-410.

2. A high-sugar diet affects cellular and humoral immune responses in Drosophila; Shichao Yu et al; Exp Cell Res. 2018 Jul 15;368(2):215-224.

3. Excess Blood Sugar Disrupts Immune System Proteins and Promotes Atherosclerosis; Weill Cornell, March 16, 2021

4. The glucose transporter GLUT3 controls T helper 17 cell responses through glycolytic-epigenetic reprogramming. Sophia M. Hochrein et al; Cell Metabolism, 2022; 

5. Microbiota imbalance induced by dietary sugar disrupts immune-mediated protection from metabolic syndrome;  Yoshinaga Kawano et al: Cell, 2022; DOI: 10.1016/j.cell.2022.08.005

6. Colon Cancer May Yield to Cellular Sugar Starvation; August 6, 2009 Johns Hopkins Medicine

7. Role of sugars in human neutrophilic phagocytosis; Albert Sanchez et al; The American Journal of Clinical Nutrition, Volume 26, Issue 11, November 1973, Pages 1180–1184, https://doi.org/10.1093/ajcn/26.11.1180

8. Glycemic modulation of tumor tolerance in a mouse model of breast cancer; Sebastian GA et al, Biochem Biophys Res,Nov 1985, Nov 15; 132 (3); 1174-9

9. Sugared Soda, cell aging, shorter telomeres; Cindy Leung UCSF

10. Fasting and cancer treatment in humans; A case series report’ Fernando M. Safdie (Cleveland Clinic, Tanya B Dorff, David Quinn USC

11. Pancreatic cancers use fructose, common in Western diet, to fuel growth. August 4, 2010 UCLA Jonsson

12. Microbiome promotes pancreatic cancer; Iain Dickson; Nat Rev Gastroenterol Hepatol; 2018 Jun;15(6):328 

13. An unhealthy gut microbiome helps worsen breast cancer - https://www.canceractive.com/article/an-unhealthy%20gut%20microbiome%20helps%20worsen%20breast%20cancer

14. High Intake of Sugar and the Balance between Pro- and Anti-Inflammatory Gut Bacteria; Reetta Satokari; Nutrients. 2020 May; 12(5): 1348. Published online 2020 May 8



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