Sugar: The Fuel That Feeds Cancer Growth

Sugar and Cancer is There a Connection?

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Dr. Colleen Huber

Our clinic which focuses on holistic, naturopathic, and alternative cancer treatments conducted the largest and longest study on sugar consumption in cancer patients, and the results were stark. Previous research has shown that high blood sugar has been risky for certain types of cancer. However, those studies were either on mice or on fewer than 20 human cancer patients. This 7-year ongoing study at our clinic has involved 317 cancer patients. We asked them to avoid all sweetened foods, except for stevia-sweetened foods. Continuing to eat sugar and sugary foods made a significant difference in survival for all stages of cancer and all types of cancer. Regardless of the type of cancer or the stage, sugar avoiders had more than twice the survival (90%) of the sugar eaters (36%). We therefore have to recommend that the diet of cancer patients not contain desserts, soda or other sweets. These results were originally published in Cancer Strategies Journal, Spring 2014.

No Sugar – A Diet That Naturally Fights Cancer

Since 2006, our clinic has collected information on sugar and cancer patients, and has actively recommended that all cancer patients avoid sweetened foods. This clinic has no food service, and is entirely an outpatient clinic. All patients chose all of their own food. We included all 317 patients who came to us with a diagnosis of cancer, and who stayed for at least two weeks in our care.

We treated our cancer paitents with natural methods alone, using research-established anti-cancer nutrients and herbs such as sodium bicarbonate and Vitamin C. These were given in IV and oral form. The high dose nutrient injections were chosen for being easily tolerated, working compatibly or synergistically with each other and for having strong anti-cancer effect. We are a naturopathic clinic, and we use the naturopathic principle of “Treat the whole person.” So the treatments are adjusted to fit individual needs and tolerance.

Choosing a good diet is of utmost importance in cancer therapy, particularly keeping blood sugar low. The existing research on the subject shows that tumors grow as blood sugar goes higher, there is a connection between sugar and cancer. This has been shown for several types of cancer: pancreatic cancer,^{1 2 3 4} breast cancer,^{5 6 7 8}  prostate cancer,^{9 10} gastric cancer, ^{11 12} colorectal cancer,^{13 14 15 16} ovarian cancer,^{17 18} endometrial cancer,^{19 20} and liver and biliary tract cancers.^{21 22}

Given all of this evidence, it would be reckless for a physician to allow a cancer patient to assume that sugar intake is harmless. We therefore ask all of our cancer patients to avoid sugar and other sweeteners, such as honey, maple syrup, molasses, corn syrup, high fructose corn syrup, alcohol, alcohol sugars and plant nectars, as well as fruit juices, because such foods tend to push the blood sugar highest (raising the glycemic index – See box). Use of stevia (Stevia rebaudiana) is encouraged if and when a sweetener is desired.

Stevia tastes sweet, in fact about 300 times sweeter than sugar. This has led to a common problem: People who are unfamiliar with it use way too much. Stevia has to be used in really tiny amounts to give just a pleasant sweet taste. But when you use too much, you are overwhelmed by such a sweet taste, that it actually gives the impression of being a little bitter. Some people seem to get turned off for life after such an experience. This is really unfortunate, because of the huge health benefits that stevia has to offer.

Stevia has actually been shown to lower blood sugar, even though it tastes sweet,²³ and has even been shown to be helpful for diabetics.²⁴ Fortunately, the sweet molecules in stevia do not enter the bloodstream.²⁵ Cancer thrives when it gets sugar delivered to it by the blood. This is the main way that cancer is able to grow. Sugar is its main fuel. So it is very useful that stevia can give the sweet tooth a treat while depriving the tumor of sugar.

For the same reason, we asked patients to also limit other refined carbohydrates, specifically flour products, because these also raise blood sugar. Whole natural foods: vegetables, fruits, whole grains, eggs, dairy and other animal proteins are encouraged as the entire diet, with the widest available variety in those groups. Many patients arrive to our clinic already consuming all of those types of foods. Others arrive with different diets. Some patients have chosen a vegan diet. Others have chosen an ovo-lacto-vegetarian diet. Many others are omnivores. Others avoid grains altogether. We have not actively pushed our patients to one or the other of these diets, because we tried to maintain the primary dietary focus on the avoidance of sweeteners, without distraction by other dietary priorities. We keep the focus exclusively on the avoidance of sugar and cancer patients  easily remember that one guideline.

Through repeated reminding, with gentle, encouraging consultation and troubleshooting of sugar and cancer, as well as brainstorming of alternative foods that may satisfy those cravings, during patient consults, we create a situation where our patients are unlikely to completely forget our recommendation when given a choice of whether to have dessert or skip dessert.

The overwhelming influence of the oncology profession on diet has suppressed this type of recommendation among many physicians. Chemotherapy IV rooms are known for having candy dishes in plain sight, despite our research that sugar and cancer are a deadly combination. Most oncologists have generally recommended that cancer patients eat desserts so intently that it seems the patients’ primary responsibility is to keep their weight up, without regard for specific health effects of various foods. Under this sugar-oriented food culture, both in the American culture at large and in the oncology clinic, other physicians tend to give in to the oncologists on this point.

However, when we started this dietary recommendation to our cancer patients in 2006, the time was already more than ripe to rebel against the sweet-tooth trend, because most of the above-cited research on sugar consumption and tumor growth had already been published. So at our clinic we decided to acknowledge the little known but already well-established connection between sugar and cancer, and thus to recommend sugar avoidance to our cancer patients.

Sugar and Cancer Growth

And Its Effect On The Body

 So let’s look at what we mean by “sugar.” Commonly the word “sugar” means sucrose, derived from sugar cane. Sucrose is a compound of glucose and fructose, and sugar is composed equally of both. High-fructose corn syrup is similar, except that it has a higher proportion of fructose to glucose. 80% of sucrose used worldwide is from cane sugar; most of the rest is from beets. It is already common knowledge that sugar is “empty calories,” that is, no protein or fat or complex carbohydrates. In its refined form it contains no nutrients at all, no vitamins, minerals, flavonoids or other antioxidants, no fiber, no amino acids. However, sugar is far more damaging to the health than simply the null effect of empty calories.

Sugar consumption was thought be 40 pounds per person per year in the U.S. in 1986.²⁶ By the early 2000s, Americans were consuming 90 pounds per person per year, which coincided with the time that one-third of Americans were obese and 14 million were diabetic.²⁷ Population studies have confirmed these findings in various countries, but the idea that sugar could be a health risk fell into disfavor in the 1970s, as American nutritionists at that time followed unquestioningly Ancel Keys and his Seven Countries Study. This study, blaming saturated fat for cardiovascular disease, had actually been a 22-country study, in which those countries that contradicted Keys’ opinions were quietly dropped from the discussion. Incidentally, those same countries were found to have a direct relationship between sugar consumption and heart disease, but that was not the widely publicized conclusion. Saturated fat became the scapegoat. In the following decades, salt would come to play the role of villain. As country after country fell victim to the damaging effects of sugar in the diet, one scapegoat after another took the blame.

The British physiologist John Yudkin found an effect of sugar consumption on obesity, diabetes and cardiovascular disease,²⁸ and brought the public’s attention to the health effects of sucrose in his 1972 book Pure, White and Deadly.²⁹ Yudkin was often personally attacked, often viciously, for writing about the diseases either caused by or worsened by sugar. In 1975, William Dufty challenged the conventional thinking on sugar with his bestseller Sugar Blues.^v Then Nancy Appleton wrote “141 Reasons Sugar Ruins Your Health,”³⁰ and Lick the Sugar Habit.³¹ In the last few years, Robert Lustig has explained the widespread damage in a way that the public is beginning to appreciate. But the best at breaking down the chemistry to clear language as well as the politics, intrigue and history of American food fights is journalist Gary Taubes, author of “Is Sugar Toxic?”³² as well as the decade-old but still current “What If It’s All Been A Big, Fat Lie?”³³ and “Why We Get Fat.”³⁴

A rapid rise in blood sugar quickly follows ingestion of pure sucrose, or sucrose-rich solids and especially liquids. Sweets accompanied by fats, proteins or fiber will enter the bloodstream slower than sweets alone in a refined carbohydrate vehicle, such as a cookie. But whether fast or slow, insulin is secreted by the pancreas in response to the presence of sugar in the blood. A lot of sudden sugar in the blood results in a lot of insulin secreted by the pancreas. When that happens too much or for too many years, the pancreas becomes depleted and can’t keep up with the body’s demand for insulin. Blood sugar rises beyond normal range, and diabetes is the diagnosis. In animal studies of sugar bingeing this process began in only a few weeks.

Cancer Growth

Tumor growth is thought to occur by way of insulin delivering sugar to cells. Cancer cells are thought to be more dependent than normal cells on sugar and cancer appears to be insatiable. Cancer’s rapid growth seems to place no limit on the sugar it can use. Insulin delivers that sugar.

Does this mean that starving the cancer cell of sugar kills the cancer cell? It is true that cancer patients on a ketogenic diet, which is a very low carbohydrate diet, seem to do somewhat better than other cancer patients. In the classic ketogenic diet, fat outweighs the total of protein and carbohydrates 4 to 1 by weight, and total carbohydrates is no more than 20 to 40 grams per day. The classic ketogenic diet eliminates simple and many complex carbohydrates: sweeteners, fruits, grains, and starchy vegetables. In animal studies, a ketogenic diet was found either to reduce the tumor size or slow tumor growth in glioblastoma, a type of brain cancer,³⁵ prostate cancer,³⁶ gastric cancer,³⁷ and lung cancer.³⁸ It was also found to improve quality of life in patients with late stage disease in a variety of cancers.³⁹

From these observations, we may not be able to jump all the way to the conclusion that sugar causes cancer, or even that getting rid of sugar gets rid of cancer. However, we can certainly become alert to the sugar and cancer connection, a cancer patient’s risks in continuing to eat sugar, and the possible benefit from eliminating it from the diet.

Results

Regarding the patients at our clinic, 29 patients acknowledged to us that they had fallen off the wagon; that is, that they ate sweetened foods at some time during their treatment. The doctors and staff try never to have a judgmental approach to our patients. If a patient has acknowledged that he or she has not abstained from sweets entirely, then we take a co-responsible (some might call it co-dependent) approach. We take responsibility for not doing a good enough job to encourage or offer ideas for satisfactory substitutes for sweets. So then during one-on-one consults we try to offer more, and more individually applicable, suggestions for the sweet cravings. For example, one person may be more drawn to alcohol, while another is more drawn to chocolate. Yet another may have a coffee habit in which coffee tastes bad without sugar. For others, it is ice cream that they want. Whether we were successful or not in persuading such individuals to adopt our recommended diet, we report that category of patient below as one who disregarded our dietary recommendation, unless they agreed to give up sweets at the beginning of treatment and stayed steadfast in that diet.

Our data is reported as of July 1, 2013. 20 patients died while still exclusively in our care, following all of our protocols, including dietary. These were all types of cancer and all stages of cancer, especially the more advanced stages. 12 more died while still in our care, but having ignored one of our main treatment recommendations, that is to avoid sweetened foods. 16 of our cancer patients have come out of remission. 5 of those are now back in remission. 4 of those 16 had discontinued our main dietary recommendation.

 

Table 1: Summarized outcomes of naturopathic management of 317 cancer cases

*DDD: death after dietary dispute.

Table 2: Summarized outcomes of naturopathic management of 29 cancer cases in which there was a dietary dispute regarding sweetener consumption

*DDD: death after dietary dispute.

Table 3: Summarized outcomes of naturopathic management of 288 cancer cases, all of whom were able to avoid consumption of sweeteners

*DDD: death after dietary dispute.

Tables 1, 2 and 3 show comparable information for three groups of patients: Table 1 summarizes all patients who presented to our clinic for cancer treatment, and who stayed in our treatments for at least two weeks. Table 2 shows the same information for those who chose to eat sweetened foods. Table 3 shows the same information for those who chose to avoid sweetened foods. The remission rate is different for all patients: 151 / 317 = 48% and those who ate sweetened foods: 9 / 29 = 31% and those who avoided sweetened foods: 142 / 288 = 49%. However, the difference in these three groups is even more pronounced if we consider those patients who stayed with our treatments until either remission or death, as in Tables 4, 5 and 6.

Table 4: Steadfast patients, by stage of cancer – all patients

*This number includes those who did not follow our dietary recommendations.

Table 5: Steadfast patients, by stage of cancer – sweet eaters

Table 6: Steadfast patients, by stage of cancer – sweetener avoiders

 

Comparing all patients who were steadfast in the treatments (Table 4) with the sweetened food eaters, who were steadfast in all but dietary recommendations (Table 5), we see that 151 / 183 = 83% went into remission, but only 9 / 25 = 36% of the sweetened food eaters went into remission. 90% of the steadfast patients who avoided sweeteners went into remission.
Of all patients who were steadfast in the treatments, (including our sweetened food eaters), 32 / 183 = 17% died, but considering only the sweetened food eaters who were otherwise steadfast in the treatments, 16 / 25 = 64% died. Of the steadfast patients who avoided sweeteners, 16 / 158 = 10% died.

Conclusion

Consuming sweetened foods (other than stevia sweetened foods) made a significant difference in patient outcome across both all stages and all types of cancer among patients presenting to our clinic. Therefore, we recommend that the diet of cancer patients not contain sweeteners other than stevia.

 

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