Looking For the Truth on Fructose? Keep Looking.

I really don’t get it. Fructose is the dietary scapegoat of the decade, blamed for everything from obesity to liver disease. Never mind that most high fructose corn syrup is in actuality no higher in fructose than regular table sugar. Never mind that the increase in fructose consumption (the so-called smoking gun) over the last ten years was accompanied by an equivalent increase in glucose consumption. Never mind that pure fructose is not found in nature or in the normal human diet–it is virtually always consumed in combination with other sugars.

There is so much myth and hysteria circulating about fructose, you would think some solid scientific inquiry would help clarify the situation. But how are we ever going to figure out what part (if any) fructose per se plays in our health problems when researchers continue to design studies that fail to isolate the variables?

For example, this latest study, published in the American Journal of Clinical Nutrition compared a diet that was high in fructose and and also provided a third too many calories with a diet that contained less fructose and the proper number of calories. Those on the “high fructose” diet experienced several unfavorable changes in their blood lipid profiles.

So what? How many of those effects were due to simply overeating? Why not compare two diets with the same number of calories but differing amounts of fructose? And please don’t show me studies that compare diets containing only fructose versus diets containing only glucose because these type of diets don’t occur outside a laboratory.

Is too much sugar to blame for many of our health woes? You bet. Is fructose metabolized differently than glucose and other sugars? For sure.  Is fructose poison to our bodies? Fructose is like any other sugar molecule: when refined, concentrated, and consumed in excess quantities, it’s not good for you.

Want to improve your health? Cut down on added sugars–that includes table sugar, HFCS, maple syrup, honey, agave nectar, fruit juice concentrates, and foods made with any of these. You’ll be cutting down on fructose in the process–if that makes you feel better.

But I’ve yet to be convinced that fructose is harmful except in cases where sugar (in general) makes up too large a proportion of calories. In these cases, the effects of fructose on the liver and blood lipids are simply one of the mechanisms by which too much sugar damages human health–no more or less dangerous than any number of other mechanisms, such as the effect of glucose on blood sugar and insulin levels, or the effect of excessive calorie intake on body fat and weight.