Researchers find no benefit in replacing fructose with glucose

St. Michael's HospitalJan 31 2014

Researchers at St. Michael's Hospital have found there is no benefit in replacing fructose, the sugar most commonly blamed for obesity, with glucose in commercially prepared foods.

The findings, published in the February edition of Current Opinion in Lipidology, show that when portion sizes and calories are the same, fructose does not cause any more harm than glucose.

"Despite concerns about fructose's link to obesity, there is no justification to replace fructose with glucose because there is no evidence of net harm," said Dr. John Sievenpiper, a researcher in the Clinical Nutrition and Risk Factor Modification Centre of St. Michael's.

Using data from previous research trials, Dr. Sievenpiper and his team compared the effects of fructose and glucose against several health risk factors. The study found that consuming fructose may increase total cholesterol and postprandial triglycerides, a type of fat found in blood. However, fructose did not appear to affect insulin production, other fat levels in the blood stream or markers of fatty liver disease any more than glucose did.

In fact, fructose showed potential benefits over glucose in some key risk factor categories.

"Some health care analysts have thought fructose to be the cause of obesity because it's metabolized differently than glucose," said Dr. Sievenpiper. "In calorie-matched conditions, we found that fructose may actually be better at promoting healthy body weight, blood pressure and glycemic control than glucose."

Fructose, a simple sugar found in honey, fruit, vegetables and other plants, is also the basis of high-fructose corn syrup - a sweetener often found in commercially prepared foods. The combination of both fructose and glucose produces sucrose, generally known as table sugar.

Dr. Sievenpiper said he feels that overconsumption, rather than a type of sugar, is one of the leading causes of obesity.

"Overall, it's not about swapping fructose with glucose," said Dr. Sievenpiper. "Overeating, portion size and calories are what we should be refocusing on - they're our biggest problems."