Sugar, OY!
July 16, 2011
Turns out now that sugar may be even worse for us than we thought. A well-written but disconcerting article in the New York Times by Gary Taubes (“Is Sugar Toxic?”, April 13, 2011) suggests that it may even be responsible for certain types of cancers. Taubes does a nice job tracing the argument that, while excessive consumption of sugar over the past 30 years is the principle reason for the skyrocketing numbers of obesity and new cases of diabetes, it may also be the cause of other chronic Western ailments such as heart disease, high blood pressure, and several common cancers.
Not just empty calories and tooth decay anymore, there is an argument that sugar may actually be killing us according to Taubes. For purposes of this argument, there is no distinction between sugar (sucrose) and high-fructose corn syrup; they are almost identical in their effects. The human body metabolizes the fructose in the corn syrup and in sugar similarly but differently than to the way it metabolizes the glucose in, say, potatoes or spaghetti. So, 100 calories of sugar will be metabolized differently than 100 calories from spaghetti. Fructose is metabolized primarily by the liver while glucose (from the spaghetti) is metabolized by every cell in the body. Sugar creates more work for the liver.
If the liver is overloaded with sugar (a can of cola, a chocolate bar) it converts to fat (in the liver) any sugar it cannot immediately use for energy. This appears to create the condition know as “insulin resistance.” This, as Taubes notes: “is now considered the fundamental problem in obesity, and the underlying defect in heart disease and in the type of diabetes, type 2, that is common to obese and overweight individuals. It might also be the underlying defect in many cancers.”
When you are insulin resistant, your pancreas responds to rising blood sugar (after a meal, for example) by pumping out more insulin to reduce blood sugar levels. If your body ignores this insulin, your pancreas attempts to create more. Eventually your pancreas concedes and your blood sugar rises out of control. Now you are diabetic. In addition, however, this chronically elevated insulin level has its own side effects: heart disease, elevated triglyceride levels, elevated blood pressure, lower levels of HDL (good) cholesterol, and further worsening of the insulin resistance. This is called “metabolic syndrome.”
So, what causes the initial insulin resistance? The answer: fat in the liver. Simply put, when you deposit fat in the liver, you become insulin resistant and this, as we have seen, triggers a cascade of bad things. What causes fat in the liver? Too much fructose (think candy, doughnuts, soft drinks, sugared fruit juices).
What about the cancer? It is well established that cancer rates are higher in the obese population and in diabetics. You are also more likely to get cancer if you have metabolic syndrome that if you do not. It has also long been established that Western diets are responsible for a large percentage of cancers. Historically. we have thought that it was the fatty meat part of this diet that was the culprit. It may actually be the sugar part. It turns out that insulin promotes tumor growth. Anything that promotes the over-secretion of insulin will enhance the development of cancerous tumors. Cancer cells have a voracious appetite for blood sugar. Insulin resistance prevents your body from using insulin to reduce blood sugar levels which leaves more sugar in the blood for the cancer cells to feed on.
If these arguments are correct, then any dietary factor that promotes insulin resistance and fat build up in the liver may lead to heart disease, diabetes, obesity, and cancer. That factor would be sugar. Its effects may be far worse than the tooth decay our mothers and dentists used to warn us about. If you are worried that you are consuming more of it than you should, call me.