A lacto-ovo-vegetarian diet, which includes eggs and dairy but excludes meat and fish, and a Mediterranean diet are likely equally effective in reducing the risk of heart disease and stroke, according to new research in the American Heart Association's journal Circulation.
Previous separate studies have shown that a Mediterranean diet reduces certain risk factors for cardiovascular disease, as does a vegetarian diet; however, this was the first study to compare effects of the two distinct eating patterns.
Current study authors said they wanted to evaluate whether switching to a lacto-ovo-vegetarian diet would also be heart-healthy in people who were used to eating both meat and fish. "To best evaluate this issue, we decided to compare a lacto-ovo-vegetarian diet with a Mediterranean diet in the same group of people," said Francesco Sofi, M.D., Ph.D, lead study author and professor of clinical nutrition at the University of Florence and Careggi University Hospital in Italy.
The study included 107 healthy but overweight participants, ages 18-75, who were randomly assigned to follow for three months either a low-calorie vegetarian diet, which included dairy and eggs, or a low-calorie Mediterranean diet for three months. The Mediterranean diet included poultry, fish and some red meat as well as fruits, vegetables, beans and whole grains. After three months, the participants switched diets. Most participants were able to stay on both diets.
Researchers found participants on either diet:
- lost about 3 pounds of body fat;
- lost about 4 pounds of weight overall; and
- experienced about the same change in body mass index, a measure of weight in relationship to height.
Authors said they did find two differences between the diets that may be noteworthy. The vegetarian diet was more effective at reducing LDL (the "bad") cholesterol, while the Mediterranean diet resulted greater reductions in triglycerides, high levels of which increase the risk for heart attack and stroke.
Still, "the take-home message of our study is that a low-calorie lacto-ovo-vegetarian diet can help patients reduce cardiovascular risk about the same as a low-calorie Mediterranean diet," Sofi said. "People have more than one choice for a heart-healthy diet."
In an editorial accompanying the study, Cheryl A. M. Anderson, Ph.D., M.P.H., M.S., an associate professor of preventive medicine at the University of California, San Diego, in California, wrote that there were similarities between the two diets that may explain the results. Both follow "a healthy dietary pattern rich in fruits and vegetables, legumes [beans], whole grains and nuts; focusing on diet variety, nutrient density and appropriate amount of food; and limiting energy intake from saturated fats."
Anderson, who was not involved in the study, added that promoting both diets by healthcare professionals "offer a possible solution to the ongoing challenges to prevent and manage obesity and cardiovascular diseases."
Study limitations include the fact that participants were at "relatively low" risk of cardiovascular disease. Anderson said future research should compare the diets in patients at higher risk for heart disease and should also explore "whether or not healthful versions of traditional diets around the world that emphasize fresh foods and limit sugars, saturated fats, and sodium can prevent and manage obesity and cardiovascular diseases."