Diet Affects Hormone
That May Protect Heart

Moderate drinking may boost levels of adiponectin -- a substance secreted by fat tissue that seems to affect how well the body responds to the sugar-processing hormone insulin -- according to the results of a study released last week.

But the study also found that a diet rich in processed carbohydrates was related to lower levels of adiponectin.

Recent studies suggest that low blood levels of adiponectin may be related to an increased risk of type 2 diabetes and coronary heart disease, according to the study's lead author, Dr. Tobias Pischon of the Harvard School of Public Health in Boston.

The results of the new study suggest that adiponectin may play a role in how a person's diet affects heart disease risk, according to Pischon and his colleagues.

But Pischon cautioned that the results need to be confirmed by studies that evaluate the effect of dietary changes on adiponectin levels. It will also be important to see whether changes in adiponectin levels explain the relationship between diet and the risk of heart disease, according to the Harvard researcher.

It is well known that diet plays an important role in the risk of heart disease and type 2 diabetes. For instance, diets high in processed carbohydrates may increase the risk of heart disease, while moderate alcohol consumption has been linked to a reduced risk.

Previous research has suggested that adiponectin affects how well the body responds to the sugar-processing hormone insulin. People who are obese or who have type 2 diabetes tend to have reduced levels of the hormone, according to Pischon.

Based on preliminary research showing a protective effect of high adiponectin levels, Pischon's team set out to see if the hormone has an effect on the relationship between diet and health risk.

In a study of 532 men, researchers found that adiponectin levels were related to consumption of alcohol, carbohydrates and fat.

With drinking, moderation seemed to be the key to boosting adiponectin levels, as moderate drinkers had the highest levels of the hormone. Teetotalers and heavy drinkers both tended to have lower levels of adiponectin.

The study also found that the more fat people ate, the higher was their level of adiponectin.

But consumption of carbohydrates, or at least certain types of carbohydrates, was related to lower levels of adiponectin. The researchers found that carbohydrates with a high glycemic load were associated with reduced levels of adiponectin.

Not all carbohydrates have the same effect on blood glucose. High-glycemic foods, including breads, doughnuts, cakes, crackers and candy, substantially boost blood sugar levels.

The importance of glycemic levels is controversial. Nonetheless, Pischon told Reuters Health, "Our study indicates that a diet with a high glycemic load - lots of processed carbohydrates - is associated with lower adiponectin levels, which may reflect the detrimental association of this diet with cardiovascular health."

But he cautioned that more research is needed to know for sure whether low adiponectin levels truly increase the risk of type 2 diabetes and heart disease.

The current report was presented on Friday during the American Heart Association's 44th Annual Conference on Cardiovascular Disease Epidemiology and Prevention in San Francisco.