Research indicates lower cholesterol is another benefit of a plant-based vegetarian diet

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New research has found that vegetarian and vegan plant-based diets can help lower levels of total cholesterol, including lower levels of "good" HDL and "bad" LDL cholesterol, when compared to a diet that includes meat.

Carried out by a team of Japanese and American researchers, the new meta-analysis looked at 49 observational and controlled studies which together included 1484 participants.

From the 30 observational studies included, the team found that a plant-based vegetarian diet is associated with total cholesterol that's 29.2 mg/dL lower, with the findings showing a 22.9 mg/dL reduction in LDL cholesterol and a 3.6 mg/dL reduction in HDL cholesterol, compared to control groups following an omnivorous diet.

From the 19 clinical trials, the team found that a plant-based diet lowers total cholesterol by 12.5 mg/dL, with LDL cholesterol reduced by 12.2 mg/dL and HDL cholesterol reduced by 3.4 mg/dL, compared to control groups following an omnivorous, low-fat, calorie-restricted, or a conventional diabetes diet.

However, a plant-based vegetarian diet was not found to be associated with statistically significant changes in triglyceride levels, a type of fat found in the blood and also associated with heart health, in either observational studies or in clinical trials.

The authors proposed that a vegetarian diet may help lower cholesterol thanks to a plant-based diet also helping to lower body weight, reduce intake of saturated fat, and increase daily intake of plant foods naturally rich in soluble fiber, soy protein, and plant sterols such as vegetables, fruits, legumes, nuts, and whole grains.

In addition, the authors also believe that sticking to a plant-based diet long-term, as seen in the longitudinal studies, also plays a role.

"The immediate health benefits of a plant-based diet, like weight loss, lower blood pressure, and improved cholesterol, are well documented in controlled studies," says study author Susan Levin, "Our goal with studying plasma lipids throughout the lifespan is to capture the net risk reduction of using a vegetarian diet to control lipid levels. We hope to empower patients with new research about the long-term cardiovascular health benefits of a vegetarian diet, which include a reduced risk of a heart attack, stroke, and premature death."

The authors noted that some doctors feeling pressured for time may not be able to provide the advice needed to patients on a vegetarian diet, but suggest instead referring patients to registered dietitians who can help make a change over to a plant-based vegetarian diet.

The 2015 Dietary Guidelines for Americans also highlights a healthy vegetarian diet as one of three healthful eating plans to follow.

The results can be found in the journal Nutrition Reviews.