Vegetarians may be at lower diabetes, heart risk

NEW YORK (Reuters Health) - A new study finds that a meat-free diet seems to lower a person's likelihood of having certain risk factors for diabetes or heart disease -- and therefore may lower the risk of one day developing those illnesses.

Researchers measured a suite of factors -- blood sugar, blood fats, blood pressure, waist size, and body mass - that when elevated add up to "metabolic syndrome," and found that vegetarians were lower than non-vegetarians on all counts except cholesterol.

Having metabolic syndrome puts people at a greater risk of developing diabetes or heart disease in the future.

In the study, 23 out of every 100 vegetarians were found to have at least three metabolic syndrome factors, compared with thirty-nine out of every 100 non-vegetarians and 37 out of every 100 semi-vegetarians.

"I was expecting there should be a difference," said Nico Rizzo of Loma Linda University, the lead researcher on the study. "But I didn't expect that it would be that much."

Rizzo and his colleagues analyzed the diet, health and lifestyles of more than 700 adults.

Using questionnaires on eating habits, the researchers categorized participants as vegetarians (eating meat of any kind less than once a month), semi-vegetarians (eating meat or poultry less than once a week), and non-vegetarians.

The researchers also measured sugar, fat and cholesterol in the subjects' blood as well as blood pressure, waist size, and body mass index (BMI -- a measurement of a person's weight relative to height).

Vegetarians' average BMI of 25.7 was four points lower than that of non-vegetarians, who, on average, had BMIs close to 30.

A BMI greater than 25 is considered overweight, and greater than 30 is considered obese.

Semi-vegetarians fell in the middle, with a BMI and waist size smaller than non-vegetarians, but larger than vegetarians.

The pattern held when the measurements were combined to determine the presence of metabolic syndrome.

Rizzo told Reuters Health he is not sure what's behind the differences.

"Is it primarily the meat intake, the plant food intake or a combination of both?" Rizzo said.

It's also possible that diet is not the cause; the research showed only an association between food choices and health factors, not cause-and-effect.

High BMI, for instance, one of the traits that make up the metabolic syndrome profile, itself contributes to high blood pressure, and indirectly, blood sugar, and thereby potentially raising a person's risk of heart disease and diabetes.

The current study, published in the journal Diabetes Care, also did not follow the subjects over the long term to see whether those who abstained from meat actually had lower rates of diabetes or heart disease.

The data for this research, which was funded by the National Institutes of Health, came from the Adventist Health Study 2, a long term study of Seventh Day Adventists.

This religious group has considerably more vegetarians than the general population.

In this study, 35 percent of the subjects did not eat meat, whereas only about five percent of all Americans are vegetarian.

One of the differences Rizzo discovered between the groups was age. Vegetarians, on average, were 3 years older than the meat-eaters.

"Even though they're older, they're in better shape," Rizzo said. "That's something I found quite interesting."

SOURCE: bit.ly/goHGBG Diabetes Care, online March 16, 2011.