Image by Uwe Hermann, Flickr
Cancer feeds on sugar
If you’ve had cancer, you’ve probably heard this. I know it’s something I’ve heard regularly from other cancer survivors as well as my own naturopath (of course, my AMA/western doctors didn’t say anything about diet, but I didn’t expect them to). I’ve also read it in some of the many cancer books I’ve read since I was diagnosed.
Too much sugar in your diet causes insulin resistance. When you eat sugar (or simple carbs), your body releases insulin to help keep your blood sugar levels consistent. If you eat too much sugar, your body (your pancreas) can’t keep up; it releases more and more insulin until it gives up. Sugar that can’t be metabolized by your body is stored as fat, and is directly related to heart disease and diabetes. In fact, some scientists now think that sugar is the main cause of heart disease, previously thought be to caused by too much fat in the diet.
It’s pretty clear that we Westerners eat way too much sugar (and way too much in general). And it’s also clear that people who eat a Western diet have a much higher incidence of cancer. From an article in the NY Times about sugar, Is Sugar Toxic (April 2011):
Malignant cancer, like diabetes, was a relatively rare disease in populations that didn’t eat Western diets, and in some of these populations it appeared to be virtually nonexistent. In the 1950s, malignant cancer among the Inuit, for instance, was still deemed sufficiently rare that physicians working in northern Canada would publish case reports in medical journals when they did diagnose a case.
In 1984, Canadian physicians published an analysis of 30 years of cancer incidence among Inuit in the western and central Arctic. While there had been a “striking increase in the incidence of cancers of modern societies” including lung and cervical cancer, they reported, there were still “conspicuous deficits” in breast-cancer rates. They could not find a single case in an Inuit patient before 1966; they could find only two cases between 1967 and 1980. Since then, as their diet became more like ours, breast cancer incidence has steadily increased among the Inuit, although it’s still significantly lower than it is in other North American ethnic groups. Diabetes rates in the Inuit have also gone from vanishingly low in the mid-20th century to high today.
Now most researchers will agree that the link between Western diet or lifestyle and cancer manifests itself through this association with obesity, diabetes and metabolic syndrome — i.e., insulin resistance. This was the conclusion, for instance, of a 2007 report published by the World Cancer Research Fund and the American Institute for Cancer Research — “Food, Nutrition, Physical Activity and the Prevention of Cancer.”
So how is sugar specifically related to cancer? Well, it turns out that many cancer cells feed directly off insulin - in fact some cancer cells mutate for the purpose of increasing insulin influence in the cell - and, as we know, insulin levels are directly related to sugar in the diet.
From the article:
Many pre-cancerous cells would never acquire the mutations that turn them into malignant tumors if they weren’t being driven by insulin to take up more and more blood sugar and metabolize it.
What these researchers call elevated insulin (or insulin-like growth factor) signaling appears to be a necessary step in many human cancers, particularly cancers like breast and colon cancer. Lewis Cantley, director of the Cancer Center at Beth Israel Deaconess Medical Center at Harvard Medical School, says that up to 80 percent of all human cancers are driven by either mutations or environmental factors that work to enhance or mimic the effect of insulin on the incipient tumor cells.
Clearly sugar isn’t good for you. It’s empty calories that are either replacing calories with more nutrition (fruits, veg), or it’s excess calories that will add to your girth. But sugar also creates more systemic health issues and sets the stage for cancer.
Since being diagnosed, I have (for the most part) avoided refined sugar entirely. I eat fruit and dried fruit regularly, but only with or after a meal of low-carb foods (vegetables, quinoa, nuts, etc.). Except for the occasional small bite of dark dark chocolate, most of my diet is refined-sugar free. I don’t know if reducing sugar will make a difference and help keep me cancer free, but given the research, I hope it will.
