STATE COLLEGE, PA. — Plant-based foods may play a key role in reducing risk for heart disease. Researchers at Penn State University found diets with reduced sulfur amino acids, which occur in protein-rich foods like meats, dairy, nuts and soy, were strongly associated with a decreased risk for cardiovascular disease. 

“For decades it has been understood that diets restricting sulfur amino acids were beneficial for longevity in animals,” said John Richie, professor of public health sciences at Penn State College of Medicine. “This study provides the first epidemiologic evidence that excessive dietary intake of sulfur amino acids may be related to chronic disease outcomes in humans.”

The study, published Feb. 3 in Lancet EClinical Medicine, examined the diets and biomarkers of more than 11,000 participants. Those who consumed high amounts of sulfur amino acid were associated with a higher cardiometabolic risk score even after accounting for factors like age, sex and history of diabetes and hypertension. Researchers also found that high sulfur amino acid intake was associated with every type of food except grains, vegetables and fruit.

“Meats and other high-protein foods are generally higher in sulfur amino acid content,” said Zhen Dong, lead author of the study. “People who eat lots of plant-based products like fruits and vegetables will consume lower amounts of sulfur amino acids. These results support some of the beneficial health effects observed in those who eat vegan or other plant-based diets.”

The average American consumes more than two times more sulfur amino acids than the average requirement, researchers said.

“Many people in the United States consume a diet rich in meat and dairy products and the estimated average requirement is only expected to meet the needs of half of healthy individuals,” said Xiang Gao, co-author of the study and director at Penn State’s nutritional epidemiology lab. “It is not surprising that many are surpassing the average requirement.”

Another recent study from Northwestern University and Cornell University, published Feb. 3 in JAMA Internal Medicine, also linked red and processed meat with higher risk of heart disease.

Eating two servings of red meat, processed meat or poultry per week was linked to a 3% to 7% higher risk of cardiovascular disease, the study found. Eating two servings of red or processed meat, but not poultry or fish, was associated with a 3% higher risk of all causes of death.

“It’s a small difference, but it’s worth trying to reduce red meat and processed meat like pepperoni, bologna and deli meats,” said Norrina Allen, author of the study and professor of preventive medicine at Northwestern University Feinberg School of Medicine. “Red meat consumption also is consistently linked to other health problems like cancer.”

These new findings come on the heels of a meta-analysis published in November, which recommended that people not reduce the amount of red meat or processed meat in their diets.

“Everyone interpreted that it was okay to eat red meat, but I don’t think that is what the science supports,” Ms. Allen said.