That’s the takeaway from a comprehensive new review by researchers at the University of Warwick in the United Kingdom. While many studies have been published that have seen an association between a plant-based diet and better heart health, they’re mostly observational studies, so it is impossible to say if the diet caused better health outcomes. But a new review, published July 23 in the Journal of Hypertension, looked only at clinical trials in which a test group was given a particular plant-based diet and a control group was given a more standard diet. “By analyzing clinical trials, we are able to establish causation that the diet in the trial led to either a positive or a negative outcome,” says Francesco Cappuccio, MD, a professor at the medical school at the University of Warwick and a senior author on the paper. “And we see in the clinical trials that the effect of the diet intervention on blood pressure is quite large.” Dr. Cappuccio and his team focused on blood pressure because it is a prominent and well-established determinant of heart disease, stroke, and metabolic diseases like diabetes. The review analyzed the effects of 41 different studies involving a total of 8,416 participants across seven different plant-based diets, in which blood pressure was studied in controlled clinical trials. The seven diets included the Dietary Approaches to Stop Hypertension, or DASH diet; the Mediterranean diet; a vegetarian diet; a vegan diet; the Nordic diet; a high fiber diet; and a high fruit and vegetable diet. RELATED: Beginner’s Guide to a Plant-Based Diet The findings may upend a bit of conventional wisdom: It turns out that the diets that had some animal protein in them had the largest effect in lowering blood pressure, while a vegan diet, which completely eliminates animal protein, had the smallest blood pressure benefit. “That’s not surprising, since a vegan diet lacks important nutrients,” says Cappuccio. “A little meat is actually important. So that’s great news for people who want to eat healthier but don’t want to give up meat and eggs. Just try to transition away from red meat, eat more plants, and go easy on the salt.”
Curb Your Appetite for Meat
As far as lowering blood pressure, the DASH diet, which encourages eating more fruits, vegetables, and whole grains while limiting the intake of sweets, saturated fat, and sodium, was the most effective. It lowered both systolic blood pressure and diastolic blood pressure more effectively than any other diet. “That result is not surprising since the diet targets hypertension specifically, but it emphasized that there is a role for animal protein in a heart-healthy diet,” says Cappuccio. In fact, several diets that included a small amount of animal protein, whether from fish or from eggs and dairy, lowered blood pressure more effectively than a vegan diet. After the DASH diet, the next two best diets for blood pressure were a vegetarian diet that included dairy and eggs, and the Nordic diet. For the uninitiated, the healthy Nordic diet, according to the study, “involves higher intake of plant foods, fish, eggs, and vegetable fat, and lower intake of meat products, dairy products, sweets, desserts, and alcoholic beverages.” One notable exception to the trend was the Mediterranean diet, which encourages the frequent consumption of vegetables, fruits, whole grains, and olive oil, as well as moderate intake of legumes, nuts, fish, dairy, and eggs, and an extremely limited intake of red meat. “While the Mediterranean diet is very healthy, it can be heavy in salt, which is why we didn’t see as large an effect as with the DASH diet,” says Cappuccio. The shift to a more plant-based diet would save lives and a tremendous amount of money in healthcare spending. The study notes that a diet that limited consumption of animal products would lead to a 14 percent reduction in strokes, a 9 percent reduction in heart attacks, and a 7 percent reduction in overall mortality from cardiovascular diseases. Cappuccio notes that beyond diseases related to blood pressure, the health benefits would extend to reductions in diet-related cancers, like colon cancer, and to improvements in overall health from an improved gut microbiome. Looking beyond human health, the study authors conclude their review by citing the ecological benefits of shifting toward a plant-based diet. They point out that livestock farming accounts for 80 percent of land use and that it takes 43,000 liters of water to produce 1 kilogram (kg) of beef. By contrast, it takes only 1,000 liters of water to produce 1 kg of grain. “If we want to save the planet and feel healthier, then this switch to a plant-based diet is a no-brainer,” says Cappuccio.
