Last Updated: 2002-11-11 17:00:35 -0400 (Reuters Health)

NEW YORK (Reuters Health) - People with diabetes may be able to lower their risk of heart disease by consuming cool foods, or dishes cooked at relatively low temperatures, such as salads and tuna fish, preliminary research suggests.

According to the study, foods cooked at high temperatures spurred the production of advanced glycation end products (AGEs), compounds in the blood that stimulate cells to produce inflammation-causing proteins, in a group of adults with diabetes.

While AGEs are normally produced in the body at a slow rate, they can be toxic and form more quickly when food is heated to high temperatures, the researchers explain in the online early edition of the journal Proceedings of the National Academy of Sciences.

Inflammation is associated with heart disease among all people, but people with diabetes are thought to be particularly vulnerable. The study points to a simple way for people with diabetes and possibly healthy individuals to reduce levels of inflammation in the body.

While most of the previous research has focused on foods people with diabetes should avoid, the current study points to the importance of food preparation methods, Dr. Helen Vlassara, the study's lead author, told Reuters Health.

"Unlike the emphasis that has been put so far on the nutrients themselves, our work really points to the mode with which we have been accustomed to preparing our food. It seems that the byproducts that we form inadvertently simply by processing our food puts us at risk," said Vlassara, from Mount Sinai School of Medicine in New York City.

She noted that a number of animal studies support these findings in humans.

"In genetically predisposed animals where we know they will develop diabetes, this (reduced AGE) diet has proven highly protective," said Vlassara. "The findings are pretty astounding."

Vlassara and colleagues fed 24 patients with diabetes one of two healthy diets that were equal in every way except the level of AGEs due to the temperature at which the foods were cooked. After 2 to 6 weeks, study volunteers switched diets.

People who consumed foods cooked at lower temperatures had lower levels of both AGEs and inflammatory proteins than people who consumed the same foods cooked at higher temperatures. After just 2 weeks, blood levels of AGEs rose by nearly 65% among individuals consuming the high-AGE diet and decreased by 30% in individuals consuming the low-AGE diet.

After 6 weeks, levels of tumor necrosis factor-alpha (TNF-alpha) and concentrations of the inflammatory protein C-reactive protein (CRP) had also risen among those consuming the diet high in AGEs and declined among those in the reduced AGE group, the researchers report. TNF-alpha and CRP are both markers showing increased inflammation.

"Further clinical studies are needed to establish this modality as a nonpharmacological intervention for diabetic macrovascular disease," Vlassara and colleagues conclude.

SOURCE: Proceedings of the National Academy of Sciences Early Edition 2002;10,1073/pnas.242437999.