Cancer's Sweet Tooth

From the April 2000 Issue of Nutrition Science News

by Patrick Quillin, PHD, RD, CNS

During the last 10 years I have worked with more than 500 cancer patients as director of nutrition
for Cancer Treatment Centers of America in Tulsa, Okla. It puzzles me why the simple concept
"sugar feeds cancer" can be so dramatically overlooked as part of a comprehensive cancer treatment

Of the 4 million cancer patients being treated in America today, hardly any are offered any
scientifically guided nutrition therapy beyond being told to "just eat good foods." Most patients I
work with arrive with a complete lack of nutritional advice. I believe many cancer patients would
have a major improvement in their outcome if they controlled the supply of cancer's preferred fuel,
glucose. By slowing the cancer's growth, patients allow their immune systems and medical
debulking therapies--chemotherapy, radiation and surgery to reduce the bulk of the tumor mass--to
catch up to the disease. Controlling one's blood-glucose levels through diet, supplements, exercise,
meditation and prescription drugs when necessary can be one of the most crucial components to a
cancer recovery program. The sound bite--sugar feeds cancer--is simple. The explanation is a little
more complex.

The 1931 Nobel laureate in medicine, German Otto Warburg, Ph.D., first discovered that cancer
cells have a fundamentally different energy metabolism compared to healthy cells. The crux of his
Nobel thesis was that malignant tumors frequently exhibit an increase in anaerobic glycolysis--a
process whereby glucose is used as a fuel by cancer cells with lactic acid as an anaerobic byproduct--compared to normal tissues.1 The large amount of lactic acid produced by this fermentation of
glucose from cancer cells is then transported to the liver. This conversion of glucose to lactate
generates a lower, more acidic pH in cancerous tissues as well as overall physical fatigue from
lactic acid buildup.2,3 Thus, larger tumors tend to exhibit a more acidic pH.4

This inefficient pathway for energy metabolism yields only 2 moles of adenosine triphosphate
(ATP) energy per mole of glucose, compared to 38 moles of ATP in the complete aerobic oxidation
of glucose. By extracting only about 5 percent (2 vs. 38 moles of ATP) of the available energy in
the food supply and the body's calorie stores, the cancer is "wasting" energy, and the patient
becomes tired and undernourished. This vicious cycle increases body wasting.5 It is one reason why
40 percent of cancer patients die from malnutrition, or cachexia.6

Hence, cancer therapies should encompass regulating blood-glucose levels via diet, supplements,
non-oral solutions for cachectic patients who lose their appetite, medication, exercise, gradual
weight loss and stress reduction. Professional guidance and patient self-discipline are crucial at this
point in the cancer process. The quest is not to eliminate sugars or carbohydrates from the diet but
rather to control blood glucose within a narrow range to help starve the cancer and bolster immune

The glycemic index is a measure of how a given food affects blood-glucose levels, with each food
assigned a numbered rating. The lower the rating, the slower the digestion and absorption process,
which provides a healthier, more gradual infusion of sugars into the bloodstream. Conversely, a
high rating means blood-glucose levels are increased quickly, which stimulates the pancreas to
secrete insulin to drop blood-sugar levels. This rapid fluctuation of blood-sugar levels is unhealthy
because of the stress it places on the body.

Sugar in the Body and Diet

Sugar is a generic term used to identify simple carbohydrates, which includes monosaccharides
such as fructose, glucose and galactose; and disaccharides such as maltose and sucrose (white table
sugar). Think of these sugars as different-shaped bricks in a wall. When fructose is the primary
monosaccharide brick in the wall, the glycemic index registers as healthier, since this simple sugar
is slowly absorbed in the gut, then converted to glucose in the liver. This makes for "time-release
foods," which offer a more gradual rise and fall in blood-glucose levels. If glucose is the primary
monosaccharide brick in the wall, the glycemic index will be higher and less healthy for the
individual. As the brick wall is torn apart in digestion, the glucose is pumped across the intestinal
wall directly into the bloodstream, rapidly raising blood-glucose levels. In other words, there is a
"window of efficacy" for glucose in the blood: levels too low make one feel lethargic and can create
clinical hypoglycemia; levels too high start creating the rippling effect of diabetic health problems.

The 1997 American Diabetes Association blood-glucose standards consider 126 mg glucose/dL
blood or greater to be diabetic; 111-125 mg/dL is impaired glucose tolerance and less than 110
mg/dL is considered normal. Meanwhile, the Paleolithic diet of our ancestors, which consisted of
lean meats, vegetables and small amounts of whole grains, nuts, seeds and fruits, is estimated to
have generated blood glucose levels between 60 and 90 mg/dL.7 Obviously, today's high-sugar diets
are having unhealthy effects as far as blood-sugar is concerned. Excess blood glucose may initiate
yeast overgrowth, blood vessel deterioration, heart disease and other health conditions.8

Understanding and using the glycemic index is an important aspect of diet modification for cancer
patients. However, there is also evidence that sugars may feed cancer more efficiently than starches
(comprised of long chains of simple sugars), making the index slightly misleading. A study of rats
fed diets with equal calories from sugars and starches, for example, found the animals on the high-
sugar diet developed more cases of breast cancer.9 The glycemic index is a useful tool in guiding
the cancer patient toward a healthier diet, but it is not infallible. By using the glycemic index alone,
one could be led to thinking a cup of white sugar is healthier than a baked potato. This is because
the glycemic index rating of a sugary food may be lower than that of a starchy food. To be safe, I
recommend less fruit, more vegetables, and little to no refined sugars in the diet of cancer patients.

What the Literature Says

A mouse model of human breast cancer demonstrated that tumors are sensitive to blood-glucose
levels. Sixty-eight mice were injected with an aggressive strain of breast cancer, and then fed diets
to induce either high blood-sugar (hyperglycemia), normoglycemia, or low blood-sugar
(hypoglycemia). There was a dose-dependent response in which the lower the blood glucose, the
greater the survival rate. After 70 days, 8 of 24 hyperglycemic mice survived compared to 16 of 24
normoglycemic and 19 of 20 hypoglycemic.10 This suggests that regulating sugar intake is key to
slowing breast tumor growth.

In a human study, ten healthy people were assessed for fasting blood-glucose levels and the
phagocytic index of neutrophils, which measures immune-cell ability to envelop and destroy
invaders such as cancer. Eating 100 g carbohydrates from glucose, sucrose, honey and orange juice
all significantly decreased the capacity of neutrophils to engulf bacteria. Starch did not have this

A four-year study at the National Institute of Public Health and Environmental Protection in the
Netherlands compared 111 biliary tract cancer patients with 480 controls. Cancer risk associated
with the intake of sugars, independent of other energy sources, more than doubled for the cancer
patients.12 Furthermore, an epidemiological study in 21 modern countries that keep track of

morbidity and mortality (Europe, North America, Japan and others) revealed that sugar intake is a
strong risk factor that contributes to higher breast cancer rates, particularly in older women.13

Limiting sugar consumption may not be the only line of defense. In fact, an interesting botanical
extract from the avocado plant (Persea americana) is showing promise as a new cancer adjunct.
When a purified avocado extract called mannoheptulose was added to a number of tumor cell lines
tested in vitro by researchers in the Department of Biochemistry at Oxford University in Britain,
they found it inhibited tumor cell glucose uptake by 25 to 75 percent, and it inhibited the enzyme
glucokinase responsible for glycolysis. It also inhibited the growth rate of the cultured tumor cell
lines. The same researchers gave lab animals a 1.7 mg/g body weight dose of mannoheptulose for
five days; it reduced tumors by 65 to 79 percent.14 Based on these studies, there is good reason to
believe that avocado extract could help cancer patients by limiting glucose to the tumor cells.

Since cancer cells derive most of their energy from anaerobic glycolysis, Joseph Gold, M.D.,
director of the Syracuse (N.Y.) Cancer Research Institute and former U.S. Air Force research
physician, surmised that a chemical called hydrazine sulfate, used in rocket fuel, could inhibit the
excessive gluconeogenesis (making sugar from amino acids) that occurs in cachectic cancer
patients. Gold's work demonstrated hydrazine sulfate's ability to slow and reverse cachexia in
advanced cancer patients. A placebo-controlled trial followed 101 cancer patients taking either 6 mg
hydrazine sulfate three times/day or placebo. After one month, 83 percent of hydrazine sulfate
patients increased their weight; compared to 53 percent on placebo.15 A similar study by the same
principal researchers, partly funded by the National Cancer Institute in Bethesda, Md., followed 65
patients. Those who took hydrazine sulfate and were in good physical condition before the study
began lived an average of 17 weeks longer.16

In 1990, I called the major cancer hospitals in the country looking for some information on the
crucial role of total parenteral nutrition (TPN) in cancer patients. Some 40 percent of cancer patients
die from cachexia.5 Yet many starving cancer patients are offered either no nutritional support or
the standard TPN solution developed for intensive care units. The solution provides 70 percent of
the calories going into the bloodstream in the form of glucose. All too often, I believe, these high-
glucose solutions for cachectic cancer patients do not help as much as would TPN solutions with
lower levels of glucose and higher levels of amino acids and lipids. These solutions would allow the
patient to build strength and would not feed the tumor.17

The medical establishment may be missing the connection between sugar and its role in
tumorigenesis. Consider the million-dollar positive emission tomography device, or PET scan,
regarded as one of the ultimate cancer-detection tools. PET scans use radioactively labeled glucose
to detect sugar-hungry tumor cells. PET scans are used to plot the progress of cancer patients and to
assess whether present protocols are effective.18

In Europe, the "sugar feeds cancer" concept is so well accepted that oncologists, or cancer doctors,
use the Systemic Cancer Multistep Therapy (SCMT) protocol. Conceived by Manfred von Ardenne
in Germany in 1965, SCMT entails injecting patients with glucose to increase blood-glucose
concentrations. This lowers pH values in cancer tissues via lactic acid formation. In turn, this
intensifies the thermal sensitivity of the malignant tumors and also induces rapid growth of the
cancer. Patients are then given whole-body hyperthermia (42 C core temperature) to further stress
the cancer cells, followed by chemotherapy or radiation.19 SCMT was tested on 103 patients with
metastasized cancer or recurrent primary tumors in a clinical phase-I study at the Von Ardenne
Institute of Applied Medical Research in Dresden, Germany. Five-year survival rates in SCMT-
treated patients increased by 25 to 50 percent, and the complete rate of tumor regression increased
by 30 to 50 percent.20 The protocol induces rapid growth of the cancer, then treats the tumor with
toxic therapies for a dramatic improvement in outcome.

The irrefutable role of glucose in the growth and metastasis of cancer cells can enhance many
therapies. Some of these include diets designed with the glycemic index in mind to regulate
increases in blood glucose, hence selectively starving the cancer cells; low-glucose TPN solutions;
avocado extract to inhibit glucose uptake in cancer cells; hydrazine sulfate to inhibit
gluconeogenesis in cancer cells; and SCMT.

A female patient in her 50s, with lung cancer, came to our clinic, having been given a death
sentence by her Florida oncologist. She was cooperative and understood the connection between
nutrition and cancer. She changed her diet considerably, leaving out 90 percent of the sugar she
used to eat. She found that wheat bread and oat cereal now had their own wild sweetness, even
without added sugar. With appropriately restrained medical therapy--including high-dose radiation
targeted to tumor sites and fractionated chemotherapy, a technique that distributes the normal one
large weekly chemo dose into a 60-hour infusion lasting days--a good attitude and an optimal
nutrition program, she beat her terminal lung cancer. I saw her the other day, five years later and
still disease-free, probably looking better than the doctor who told her there was no hope.

Patrick Quillin, Ph.D., R.D., C.N.S., is director of nutrition for Cancer Treatment Centers of
America in Tulsa, Okla., and author of Beating Cancer With Nutrition (Nutrition Times Press,


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