Eating a lot of high protein foods like meat and dairy has been linked to an increased risk of heart disease. The reason for this has traditionally been the saturated fat and cholesterol contained in those foods, but there's another component in high protein foods that may be part of the puzzle as well. Sulfur, a key element of two amino acids in proteins, may also be implicated.
Proteins are made up of strands of amino acids. Two amino acids, methionine and cysteine, contain sulfur in their structure. Sulfur is important for forming the shape of proteins.
Researchers at Penn State College of Medicine looked at the diets and blood biomarkers of over 11,000 people who participated in the Third National Examination and Nutritional Health Survey. They assigned a cardiometabolic disease risk score based on the levels of certain biomarkers in the blood. These biomarkers included cholesterol, triglycerides, glucose and insulin. They were measured after people fasted for 10 to 16 hours.
Higher sulfur amino acid intake was linked with a higher cardiometabolic risk score after taking factors like age, sex and history of diabetes or high blood pressure into consideration.
Dietary information was collected from the participants, and then nutrient intakes were estimated using the U.S. Department of Agriculture Survey Nutrient Database.
The average amount of sulfur consumed was nearly two and a half times more than the estimated average requirement for humans. Higher sulfur amino acid intake was linked with a higher cardiometabolic risk score after taking factors like age, sex, and history of diabetes or high blood pressure into consideration. With the exception of grains, vegetables and fruits, every other type of food contributed to a high sulfur amino acid intake.
The high sulfur intake among the people in the study is likely the result of trends in the way the average American eats.
Some plant foods include sulfur-containing amino acids, but it’s unlikely that a person could over-consume sulfur eating them.
“Many people in the United States consume a diet rich in meat and dairy products and the estimated average [sulfur] requirement is only expected to meet the needs of half of healthy individuals,” said Xiang Gao of Penn State University, in a statement. “Therefore, it is not surprising that many are surpassing the average requirement when considering these foods contain higher amounts of sulfur amino acids.”
Some plant foods like nuts and soy include sulfur-containing amino acids, but it’s unlikely that a person would overconsume sulfur eating a plant-based diet. Here is a primer for helping you move toward a more plant-based diet.
The study is another indicator of the benefits of eating a plant-based diet, though more research is needed to pinpoint the relationship between sulfur amino acids and health outcomes over time.
The investigation is published in Lancet EClinical Medicine.