Vegetarians may have lower risk of heart disease
Previous research has also suggested that non-meat eaters have fewer heart problems, said researchers publishing in the American Journal of Clinical Nutrition, but it wasn't clear if other lifestyle differences, such as exercise and smoking habits, might also play into that.
"We're able to be slightly more certain that it is something that's in the vegetarian diet that's causing vegetarians to have a lower risk of heart disease," said Francesca Crowe, who led the new study at the University of Oxford.
Crowe and her colleagues tracked almost 45,000 people living in England and Scotland who initially reported on their diet, lifestyle and general health in the 1990s. At the start of the study, about one-third of the participants said they ate a vegetarian diet, without meat or fish.
Over the next 11 to 12 years, 1,086 of the study subjects were hospitalized for heart disease, including heart attacks, and 169 died.
After taking into account participants' ages, exercise habits and other health measures, the research team found vegetarians were 32 percent less likely to develop heart disease than carnivores. When weight was factored into the equation, the effect dropped slightly to 28 percent.
The lower heart risk was likely due to lower cholesterol and blood pressure among vegetarians in the study, the researchers said.
Meat eaters had an average total cholesterol of 222 mg/dL and a systolic blood pressure - the top number in a blood pressure reading -- of 134 mm Hg, compared to 203 mg/dL total cholesterol and 131 mm Hg systolic blood pressure among vegetarians.
Diastolic blood pressure - the lower number -- was similar between the two groups.
Crowe said the difference in cholesterol levels between meat eaters and vegetarians was equivalent to about half the benefit someone would see by taking a statin medication.
The effect is probably at least partly due to the lack of red meat - especially meat high in saturated fat - in vegetarians' diets, she added. The extra fruits, vegetables and higher fiber in a non-meat diet could also play a role.
"If people want to reduce their risk of heart disease by changing their diet, one way of doing that is to follow a vegetarian diet," Crowe told Reuters Health.
However, just scaling back on saturated fat can also make a difference. Butter, ice cream, cheeses and meats all typically contain saturated fat.