We’ve heard of the health benefits of a plant-based diet for many years. If you eat enough protein on a vegetarian diet, you can reduce your risk of a variety of health problems from diabetes to stroke to early death. In fact a new study, just in time for American Heart Month in February, shows just how beneficial the diet can be to the health of your heart, and your risk of dying from heart disease.

The researchers followed 45,000 British participants who were enrolled in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Oxford study. Of the participants, just over one-third were vegetarian, an unusually high number for a study like this, which allowed the researchers to make more meaningful comparisons between vegetarians and non-vegetarians.

Vegetarians had lower body mass indices (BMI) than non-vegetarian counterparts; but when this difference was factored out, the reduced risk of heart disease only changed minimally, suggesting there was much more to the connection than body weight alone.

There were 1235 cases of ischemic heart disease (IHD) among the participants over the course of the study, which lasted for more than 11 years. IHD occurs when the heart doesn’t get enough oxygen, and of these cases, 169 of the participants died from it.

The vegetarians had a whopping 32% lower risk of developing IHD than non-vegetarians. They also had lower body mass indices (BMI) but when this difference was factored out, the reduced risk of IHD only changed minimally, suggesting there was much more to the connection than body weight alone. The clear difference in heart risk was still present when other lifestyle factors, like smoking, age, activity level, alcohol consumption, and socioeconomic status were all considered.

The vegetarian participants also had lower blood pressure and non-HDL cholesterol levels (that is, the "bad" cholesterol, LDL, and ultra-bad cholesterol) than meat eaters. The authors say that the big difference in heart risk is likely due to these factors, along with the lesser amounts of polyunsaturated fats, compared to saturated fats, found in vegetarian diets.

While the authors do say that diet can play an important role in the prevention of heart disease, they don’t say that everyone should switch to vegetarianism as a matter of course. It’s important to do what feels right for your body, and if you are going to embark on a vegetarian diet, talk to your doctor first and make sure to get all the essential nutrients your body needs.

The research is encouraging. It adds to the growing body of evidence suggesting that what we eat, in addition to the other lifestyle choices we make each day, can have a profound effect on our health and longevity.

The study was carried out by a team at the University of Oxford, and published in the American Journal of Clinical Nutrition.