More than two-thirds of Americans are overweight and nearly one-third are clinically obese. Researchers reviewed whether the consumption of fructose contributes to obesity and insulin resistance syndrome, which is a combination of risk factors for type 2 diabetes, including chronically elevated insulin levels, low HDL ("good") cholesterol, abdominal obesity and high blood pressure.

Fructose, compared with glucose, is preferentially metabolized to fat in your liver.

It was found that in animal models fructose consumption produces:

• Insulin resistance
• Impaired glucose tolerance
• High insulin levels
• High triglycerides
• Hypertension

I prefer butter to margarine, because I trust cows more than I trust chemists - Joan Dye Gussow

Americans' consumption of fructose, as a combination of sucrose and high-fructose corn syrup, has increased by 26 percent from 1970 to 1997. The intake of dietary fructose has increased markedly as a result of the steady increase of added sugars to the American diet.

In the past, fructose was considered to be beneficial to diabetes mellitus and insulin resistance because ingesting it results in smaller postprandial glycemic and insulin excursions than do glucose and complex carbohydrates. However, other hormonal factors suggest that fructose actually promotes disease more than glucose. Also, fructose, but not glucose, is metabolized to fat in your liver.

Researchers conclude that added fructose (in the forms of sucrose and high-fructose corn syrup) does not appear to be the optimal choice as a source of carbohydrate in the diet.

Small amounts of added fructose are probably benign. However, on the basis of the available data regarding the endocrine and metabolic effects of consuming large quantities of fructose, and the potential to exacerbate components of insulin resistance syndrome, it is preferable to primarily consume dietary carbohydrates in the form of glucose (free glucose and starch).

This is particularly important for those with existing high cholesterol levels or insulin resistance who could be more susceptible to the negative metabolic effects of fructose. An acceptable alternative would be either "sugar like" Xylitol or Stevia

American Journal of Clinical Nutrition
November 2002 Vol. 76, No. 5, 911-922