The Fructose Puzzle
Health Guide July 14, 2006
Fructose is a strange sugar. It is the sweetest natural sugar, yet it has the lowest glycemic index of any sugar. Nutritionists often recommend that people with diabetes use fructose.
Many of our favorite fruits and vegetables get their sweetness from fructose. We love honey, tree fruits, berries, and melons because of the fructose they have. Vegetables such as beets, sweet potatoes, parsnips, and onions are also loaded with fructose.
And yet many people link our increased consumption of fructose to the national obesity epidemic. Generally, these people aren’t talking about the fructose in fruits and vegetables. Most of them are, however, concerned about the fructose in high fructose corn syrup, which we are consuming ever more of, particularly in soft drinks.
Some people, including Joe Anderson, who has written persuasively about the dangers of eating foods that produce foods high in advanced glycation end products (AGEs) also rails against fructose in any form – including that in fruit. That’s an extreme position. But even scientists and the American Diabetes Association warn that fructose can increase cholesterol levels.
“Fructose may adversely effect plasma lipids,” the ADA says. “Therefore, the use of added fructose as a sweetening agent is not recommended; however, there is no reason to recommend that people with diabetes avoid naturally occurring fructose in fruits, vegetables, and other foods.”
John P. Bantle, M.D., has just published the most knowledgeable and professional review of the pros and cons of using fructose. His article, “Is fructose the optimal low glycemic index sweetener?” just came out in the Nestlé Nutrition workshop series: Clinical & performance programme. Only the abstract is online, but Dr. Bantle kindly sent me a copy of his manuscript.
Dr. Bantle is professor of medicine in the division of endocrinology and diabetes at the University of Minnesota. It was largely his earlier research that prompted the ADA to recommend against our using added fructose. For some unexplained reason, fructose is particularly bad for the cholesterol levels of men.
That’s clear. But what about the fructose in fruit and vegetables?
This summer I have been eating a lot of the wonderful fruit that we grow here in Colorado. In fact, as I was writing this piece I savored an organic local apricot. Should I worry?
Dr. Bantle says no. “Fructose that occurs naturally in fruits and vegetables is a modest component of energy intake and should not be of concern,” he writes in his new article. The conclusion reads, “Adding large amounts of fructose to the diet may be undesirable. Never-the-less, concern about fructose should not extend to the naturally occurring fructose in fruits and vegetables. These are healthy foods which provide only a modest amount of fructose in most diets.”
Dr. Bantle’s conclusion is a logical one. As far back as the Romans, clear thinkers have argued that we should not bother with trifles. The concept is even embodied in American law.
Many years ago I was an officer of the U.S. Agency for International Development, America’s foreign aid program. I still remember how our staff lawyers impressed me with their ability to get around onerous restrictions that the Congress placed on our ability to do the many little jobs that we had to do.
One of the legal tools that the lawyers used again and again was something they called “de minimis.” It comes from the Latin phrase, de minimis non curat lex, which means that the law is not interested in trivial matters.
For the rest of my life I have dismissed trivialities as de minimis. Likewise, I hereby dismiss any concern about the fructose in fruit and vegetables as de minimis.