While consumers may not have even blinked when the use of high fructose corn syrup replaced sucrose (table sugar) as a sweetener several years ago, new research is showing that fructose has the ability to significantly raise triglyceride levels, which may increase the risk of heart disease.
Researchers from the University of California (Davis) note that "The introduction of high fructose corn syrup as a substitute sweetener for sucrose in the mid-1970s has contributed to a general increase in fructose consumption in the U.S. diet."
Researchers from the University of Minnesota note that "About 9% of average dietary energy intake in the United States comes from fructose. Such a high consumption raises concern about the metabolic effects of this sugar."
- In the University of Minnesota study, researchers studied 24 healthy adults, who received one of 2 diets assigned randomly for a period of 6 weeks and then switched to the other diet for 6 weeks.
- One diet provided 17% of energy as fructose and the other diet was sweetened with glucose and was nearly devoid of fructose.
- Both diets were composed of common foods and contained nearly identical amounts of carbohydrate, protein, fat, fiber, cholesterol, and saturated, monounsaturated, and polyunsaturated fatty acids.
- In men, the fructose diet raised plasma triglyceride levels by 32%, although there was no effect seen with the women being studied.
The authors conclude that "Diets high in added fructose may be undesirable, particularly for men."
In the University of California (Davis) study, researchers found that "Dietary fructose significantly increased serum triglyceride concentration across the life span in rats." This increase occurred regardless of whether or not the rats were fed calorie restricted diets or had free access to food.
American Journal of Clinical Nutrition, November 2000; 72: 1128-1134 and Journal of Nutrition, December 2000;130:3077-3084
For some crazy reason, the delusion that fructose is an acceptable form of sugar is quite prevalent in many nutritional circles. These studies are important contributions to the scientific literature that confirms that it is not. Nearly all simple sugars are metabolized quickly and disrupt insulin levels which contributes to most chronic illness. So don't be fooled and avoid fructose just like you would table sugar as they both cause similar problems.
This doesn't mean that one should avoid fruit, however. Eating small amounts of whole fruit will NOT provide tremendous amounts of fructose, and should not be a problem for most people, unless diabetes or obesity is an issue. However, fruit juices, sodas, and other beverages sweetened with fructose should be avoided.