Increased Protein Intake Could Reduce Atrial Fibrillation In Older Women

Daniel Gerber, MD

A new study examining the impact of increased protein intake in older women has returned promising results showing a potential reduction in the risk of one of the most common cardiovascular conditions.

Results of the Stanford University analysis, which included data on nearly 100k post-menopausal women, suggest consuming between 58-74 grams of protein—a range slightly higher than average—reduce the risk of atrial fibrillation (AF) up to 8%.

“Based on our findings, it seems that eating more protein may not only help strengthen women physically, but it may also have cardiovascular benefits in terms of reducing AFib and related death, strokes and heart failure,” said Daniel Gerber, MD, cardiovascular medicine fellow at Stanford University, who presented the study at the American College of Cardiology’s Annual Scientific Session Together with World Congress of Cardiology (ACC.20/WCC) in a statement.

With AF posing a serious threat to a person’s cardiovascular health—and data suggesting older women can lose a half a pound of lean body mass per year—investigators sought to assess how increased protein consumption in postmenopausal women might impact the risk of AF. With this in mind, Gerber and colleagues performed a secondary analysis of data from the Women’s Health Initiative Randomized Controlled Trials and Observational Study.

From the study, a cohort of 99,554 women—with a mean age of 64 years—were identified for inclusion in the study. All women included in the study complete food questionnaires that had been validated throughout the Nutritional Biomarkers Study. The primary outcome of interest for the analysis was incident AF—identified through Medicare claims diagnosis codes.

Investigators used multivariate Cox proportional hazard regression analysis adjusted for factors including age, ethnicity, education, physical activity, BMI, tobacco and alcohol use, and multiple comorbidities. To compare the groups, investigators divided patients into quartiles based on their protein intake per day—defined as less than 58 grams, 58-66 grams, 66-74 grams, and more than 74 grams per day.

Incident AF was identified in 21,258 women (21.3%) over a 10.1-year average follow-up and the median protein intake was 66 grams per day. When compared to women in the lowest quartile of protein intake, women consuming 58-66 grams per day (HR, 0.932, P = .001) and those consuming 66-74 grams per day (HR, 0.908, P = .0005) had a significantly lower risk of AF.

Investigators noted the apparent benefit was no longer statistically significant when intake exceeded 74 grams per day (HR, 0.951, P = .186) and results indicated physical activity did not significantly modify the impact of protein intake on incident AF. Investigators also acknowledged the retrospective and observational design of their study limit the applicability of results in a real-world setting.

“Women with the lowest protein intake—which was roughly equivalent to the current recommended daily amount of protein in the U.S.— had the highest incidence of AFib, and eating a little more was protective, even after taking into account other factors that can predispose someone to develop AFib,” Gerber said in the aforementioned statement.

This study, “Dietary Protein Intake and Incident Atrial Fibrillation in Postmenopausal Women from the Women’s Health Initiative,” was presented at ACC.20/WCC.