Plant-based diet may lessen risk for cardiovascular disease

A plant-based diet may be key to lowering risk for heart disease, according to new research by Pennsylvania State University and published in The Lancet journal EClinicalMedicine.

Researchers led by John Richie, PhD, examined the diets and blood biomarkers of more than 11,000 participants from the Third National Examination and Nutritional Health Survey and found that participants who ate foods containing fewer sulfur amino acids tended to have a decreased risk for cardiometabolic disease based on their bloodwork. They compiled a composite cardiometabolic disease risk score based on the levels of certain biomarkers in participants' blood after a 10 to 16 hour fast including cholesterol, triglycerides, glucose, and insulin.

Participants were excluded from the study if they reported having either congestive heart failure, heart attack or a reported change in diet due to a heart disease diagnosis. Individuals were also omitted if they reported a dietary intake of sulfur amino acids below the estimated average requirement recommended by the Food and Nutrition Board of the National Academy of Medicine.

The researchers determined that diets with reduced sulfur amino acids, which occur in protein-rich foods, such as meats, dairy, nuts and soy, were associated with a decreased risk for cardiovascular disease. The team also found that the average American consumes almost two and a half times more sulfur amino acids than the estimated average requirement.

Amino acids are the building blocks of proteins. A subcategory, called sulfur amino acids, including methionine and cysteine, play various roles in metabolism and health.

For a person weighing 132 pounds, food choices for a day that meet the requirement might include a medium slice of bread, a half an avocado, an egg, a half cup of raw cabbage, six cherry tomatoes, two ounces of chicken breast, a cup of brown rice, three quarters of a cup of zucchini, three tablespoons of butter, a cup of spinach, a medium apple, an eight inch diameter pizza, and a tablespoon of almonds. Nutritionists collected information about participants' diets by doing in-person 24-hour recalls. Nutrient intakes were then calculated using the U.S. Department of Agriculture Survey Nutrient Database.

After accounting for body weight, the researchers found that average sulfur amino acid intake was almost two and a half times higher than the estimated average requirement. The researchers found that higher sulfur amino acid intake was associated with a higher composite cardiometabolic risk score after accounting for potential confounders like age, sex and history of diabetes and hypertension. They also found that high sulfur amino acid intake was associated with every type of food except grains, vegetables, and fruit.

"For decades it has been understood that diets restricting sulfur amino acids were beneficial for longevity in animals," said Richie in a statement. "This study provides the first epidemiologic evidence that excessive dietary intake of sulfur amino acids may be related to chronic disease outcomes in humans."