Healthnotes Newswire (June 7, 2007)—Choosing the correct cooking method can contribute to healthy aging. New research suggests that cooking at high temperatures—as when broiling, roasting, frying, or grilling—results in toxic compounds in food that promote inflammation and increase the amount of tissue damage from free radicals (oxidative stress). These compounds, which increase risk of heart disease and other chronic illnesses, are less likely to form under gentler cooking methods such as boiling, steaming, or poaching.
Advanced glycation end products (AGEs) are created when proteins or fats react with certain sugars during high-temperature cooking. These compounds are absorbed into the body’s tissues, where they can have a number of damaging effects. In mice, for example, reducing AGEs in the diet by altering the food preparation method reduced oxidative stress, improved insulin sensitivity, and prolonged the animals’ lives.
“We reasoned that systemic glycotoxins [AGEs] accumulate with age, probably as a result of lifelong exposure to high levels of AGEs in the diet,” said Jaime Uribarri, MD, of the Mount Sinai School of Medicine and lead author of the new study. If these compounds do accumulate in the body, then eating a diet high in AGEs might promote oxidative stress, insulin resistance, and inflammation.
In studying a group of healthy volunteers, Dr. Uribarri and colleagues found that people who had higher blood levels of AGEs had more free radical formation and greater insulin resistance than people who had lower blood levels of AGEs. In addition, eating more AGEs was associated with higher levels of C-reactive protein, a marker of inflammation that is also an important risk factor for cardiovascular disease. In a previous study, the same researchers showed that people could reduce their C-reactive protein level by altering cooking methods to reduce the AGE content of the diet.
AGE formation increases when food is cooked at high temperatures and decreases when water is used in the cooking process, such as in boiling, steaming, or poaching. For example, AGE concentration is nine times as high in oven-fried chicken and five times as high in broiled chicken as it is in boiled chicken. French fried potatoes contain 90 times more AGEs than boiled potatoes. And some commercial dried cereals, which are prepared under high temperatures, have more than 100 times the AGE content of oatmeal.
The findings from this research suggest that good health and disease prevention depend not only on the types of food a person eats, but also on how those foods are prepared. As Dr. Uribarri pointed out, “Consumption of a diet which contains a moderately low amount of AGEs may be beneficial to healthy aging.”
(J Gerontol A Biol Sci Med Sci 2007;62:427–3)
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