FRIDAY, Dec. 15 (HealthDay News) -- As a child's IQ rises, his taste for meat in adulthood declines, a new study suggests.

British researchers have found that children's IQ predicts their likelihood of becoming vegetarians as young adults -- lowering their risk for cardiovascular disease in the process. The finding could explain the link between smarts and better health, the investigators say.

"Brighter people tend to have healthier dietary habits," concluded lead author Catharine Gale, a senior research fellow at the MRC Epidemiology Resource Centre of the University of Southampton and Southampton General Hospital.

Recent studies suggest that vegetarianism may be associated with lower cholesterol, reduced risk of obesity and heart disease. This might explain why children with high IQs tend to have a lower risk of heart disease in later life.

The report is published in the Dec. 15 online edition of the British Medical Journal.

"We know from other studies that brighter children tend to behave in a healthier fashion as adults -- they're less likely to smoke, less likely to be overweight, less likely to have high blood pressure and more likely to take strenuous exercise," Gale said. "This study provides further evidence that people with a higher IQ tend to have a healthier lifestyle."

In the study, Gale's team collected data on nearly 8,200 men and women aged 30, whose IQ had been tested when they were 10 years of age.

"Children who scored higher on IQ tests at age 10 were more likely than those who got lower scores to report that they were vegetarian at the age of 30," Gale said.

The researchers found that 4.5 percent of participants were vegetarians. Of these, 2.5 percent were vegan, and 33.6 percent said they were vegetarian but also ate fish or chicken.

There was no difference in IQ score between strict vegetarians and those who said they were vegetarian but who said they ate fish or chicken, the researchers add.

Vegetarians were more likely to be female, of higher social class and better educated, but IQ was still a significant predictor of being vegetarian after adjustment for these factors, Gale said.

"Vegetarian diets are associated with lower cardiovascular disease risk in a number of studies, so these findings suggest that a such a diet may help to explain why children or adolescents with a higher IQ have a lower risk of coronary heart disease as adults," Gale said.

One expert said the findings aren't the whole answer, however.

"This study left many unanswered questions such as: Did the vegetarian children grow up in a household with a vegetarian parent? Were meatless meals regularly served in the household? Were the children eating a primarily vegetarian diet at the age of 10?" said Lona Sandon, an assistant professor of clinical nutrition at the University of Texas Southwestern Medical Center at Dallas.

"In addition, we don't know the beliefs or attitudes of the parents of the children, nor do we know if there was a particular event that led these children to becoming vegetarian in their teens or adulthood," Sandon said.

As the study showed, more women than men chose a vegetarian diet, Sandon noted. "Other research shows that women in general will focus more on their health than men. So, if they believe that a vegetarian diet will have health benefits, they are more likely to follow it," she said.

Given these factors, "we cannot draw any solid conclusions from this research," Sandon added.

Another expert agreed that a vegetarian diet is healthy.

"The evidence linking vegetarianism to good health outcomes is very strong," said Dr. David L. Katz, the director of the Prevention Research Center and an associate professor of public health at the Yale University School of Medicine.

"Studies, for example, of vegetarian Seventh-Day Adventists in California suggest that they have lower rates of almost all major chronic diseases, and greater longevity, than their omnivorous counterparts," Katz said. "Evidence is also strong and consistent that greater intelligence, higher education, and loftier social status -- which tend to cluster with one another -- also correlate with good health."

More information

There's more on vegetarian diets at the U.S. Department of Agriculture.