Fructose Fuels Type 2 Diabetes

by David Mendosa Patient Advocate

Reducing how much fructose you eat without compromising your fruit intake may be the best way to start managing your diabetes if your blood sugar levels are higher than you would like them to be.

These are the main messages of a special article written by a cardiovascular research scientist at Saint Luke's Mid America Heart Institute in Kansas City, Missouri, and by two M.D. co-authors in a mainstream professional diabetes journal. The results of the study take direct aim at the lax standards of the American Diabetes Association and the 2010 Dietary Guidelines for Americans.

Now that the American medical profession is beginning to realize how big a danger that fructose is for us I hope that the twin epidemics of diabetes and obesity can finally be halted. But for each of us individually the more important message is that we can still save our health if we avoid added fructose.** The phrase "added fructose" means the fructose that we add to what we eat. The sugar in fruit is of course fructose, but essentially all experts agree that it isn't a problem because we get that fructose along with fiber, antioxidants, and the other good stuff in whole foods.** But added fructose includes what we simply call sugar, table sugar, or sucrose. These three terms all mean the same thing sugar that is half fructose and half glucose. Added fructose also includes high fructose corn syrup (HFCS), the sweetener that we usually get in soft drinks.

In HFCS, fructose is nearly 50 percent of its weight, while the fructose in a fresh peach, for example, is only about 1 percent of its weight. The new review also suggests that 100 percent fruit juice, although it technically is not a sugar-sweetened drink, has such high concentrations of fructose that it also provides fuel for the diabetes and obesity epidemics.

For the past week I have been studying the new review of the trouble with fructose, courtesy of the publisher, Mayo Clinic Proceedings. They provided me with an advance copy with my agreement that I wouldn't publish this post until now, what journalists call being "under embargo." Now that they just published the study, the full-text of which is online here, "Added Fructose: A Principal Driver of Type 2 Diabetes Mellitus and Its Consequences," I am able to share it.

This mainstream recognition comes as a welcome surprise to me. The recognition of fructose as the most dangerous sugar is no longer just a leading edge theory. I have been warning about its dangers for years, most recently in "Diabetes Without Sugar" about two years ago.

Of course, sucrose and fructose aren't the only sugars. Glucose, which has a much higher
glycemic index, will raise our blood sugar more, but paradoxically it will do much less damage to our bodies. Other sugars, including the lactose in milk are also less dangerous than fructose unless you are lactose intolerant.

Of all the carbohydrates, fructose is the most harmful. Dr. James J. DiNicolantonio, the lead author, says that the overconsumption of fructose deranges both our metabolism and insulin resistance. Several clinical trials have in fact shown that compared with glucose or starch, exchanging equal calories of them with fructose or sucrose leads to higher fasting insulin levels and high fasting glucose levels.

Most people find it hard to understand why fructose is harmful, especially because it has the lowest glycemic index of any sugar. That's why the food industry can get away with promoting the mistake that agave nectar is good for people with diabetes. It's a question of our liver, something that I am especially sensitive to because my wife, who had type 2 diabetes as I do, died from liver failure. Unlike the other sugars, the liver is the only organ in our bodies that can metabolize fructose in significant amounts. Concentrated fructose loads in both human and animal studies decrease the adenosine triphosphate (ATP) content of our liver. Biologists consider ATP "to be the energy currency of life." Decreased levels of it seem to lead to decreased cellular binding of insulin, a possible reduction in the number of insulin receptors, and subsequent insulin resistance.

Maybe you already knew this and don't add any sugar at the table. Good for you. But did you realize how much of stuff that we buy at our supermarkets includes added fructose?

In my article about "Diabetes Without Sugar," you might have noticed a statement that still shocks me. "Three-fourths of all the foods for sale in America have added sweeteners, according to an analysis of 85,451 foods that Dr. Barry Popkin of the University of North Carolina and his team studied." My main message is to avoid adding any fructose to what we eat at home. I know that it's essentially impossible to avoid added sugar when we eat out. But we can manage our sugar at home. We have to stop using the sugar spoon, avoid sugar-sweetened soft drinks, and read the Nutrition Facts labels of all the foods we buy and avoid those that include any of the myriad form of sugar. That's enough to take a giant step forward in managing diabetes.

David Mendosa
Meet Our Writer
David Mendosa

David Mendosa was a journalist who learned in 1994 that he had type 2 diabetes, which he wrote about exclusively. He died in May 2017 after a short illness unrelated to diabetes. He wrote thousands of diabetes articles, two books about it, created one of the first diabetes websites, and published a monthly newsletter, “Diabetes Update.” His very low-carbohydrate diet, A1C level of 5.3, and BMI of 19.8 kept his diabetes in remission without any drugs until his death.