Sugar holds a special place in the dietary consciousness of many people with diabetes. When they first receive their diagnosis, many people worry that they will no longer be able to enjoy their favorite sweet treats — before being reassured, in many cases, that there is no one food they must give up. Many people, in fact — including medical professionals — subscribe to the view that in people with diabetes, sugar intake is unimportant aside from its contribution toward total carbohydrate intake.
A competing view of sugar, however, has been voiced for decades but has recently gained prominence due to the advocacy of Robert Lustig, MD, an obesity expert at the University of California, San Francisco, School of Medicine. Lustig believes that sugar is a toxin, with a unique role in the development of metabolic syndrome (the common coexistence of insulin resistance, hypertension, obesity, and abnormal blood lipid levels). In 2009, Lustig gave a lecture entitled “Sugar: The Bitter Truth,” which has since attracted more than a million views on YouTube. In the lecture, he posits that fructose — which makes up 50% of table sugar or sucrose, and a slightly higher percentage of high-fructose corn syrup — is metabolized by the liver in such a way that a toxic by-product is produced, which may be responsible for health problems that have become more common at the same time that sugar consumption has risen.
In an article published last week in The New York Times Magazine, science writer Gary Taubes examines Lustig’s case and comes mostly to agree with it — while noting that the evidence is not conclusive. Taubes notes that the last official examination of sugar by US health authorities, at the Institutes of Medicine in 2005, found potential negative effects from sugar consumption but did not set a goal for the upper limit of sugar consumption. An often-cited older government study, however, conducted by the FDA in 1986, found that sugar consumption at 40 pounds per person per year could not be significantly linked to negative effects on health. Department of Agriculture estimates at the time, however, put average sugar consumption at 75 pounds per person per year, and by the early 2000s that number had risen to 90 pounds per person per year. At roughly the same time, the obesity rate rose from 1 in 7 Americans in 1980 to 1 in 3 in the early 2000s, and the rate of diagnosed diabetes rose from less than 3% in 1980 to more than 5% in the early 2000s. Taubes also links sugar — less forcefully, based on the role of insulin in the growth of tumors — to certain forms of cancer.
Of course, these assertions have not been backed up by a large-scale, multiyear, randomized controlled study on sugar consumption — and such a study would be very difficult to conduct. Moreover, it is unclear what effect sugar would have on people who already have Type 2 diabetes even if it played a distinct role in the development of the disease. Nevertheless, Taubes’s article raises questions that are relevant to all people with diabetes.
Do you believe that sugar might have played a role in your developing diabetes? What role does sugar currently play in your diet? Do you make a distinction among sucrose, high-fructose corn syrup, and natural sugar found in fruits and vegetables? How much sugar — whether added refined sugars, or natural ones — is too much? Leave a comment below!