Findings from a Cleveland Clinic trial show that six commonly used dietary supplements marketed for improving heart health did not lower “bad cholesterol” when compared to a low-dose cholesterol-lowering medication (also known as a statin) or placebo. The six supplements studied included fish oil, garlic, cinnamon, turmeric, plant sterols and red yeast rice.
Results from the Supplements, Placebo or Rosuvastatin Study (SPORT) were presented today during a late-breaking science session at the American Heart Association’s Scientific Sessions 2022 and simultaneously published in the Journal of the American College of Cardiology.
“If you’re taking over-the-counter supplements for heart health or for cholesterol lowering, you should reconsider,” said Luke Laffin, M.D., study author and co-director of the Center for Blood Pressure Disorders in the Heart, Vascular & Thoracic Institute at Cleveland Clinic. “Unfortunately, many U.S. consumers believe cholesterol health supplements are safer than prescription medications and believe supplements are as effective, or more effective, than statins.”
Marketing of dietary supplements is regulated under the Dietary Supplement Health and Education Act of 1994 and overseen by the U.S. Federal Trade Commission rather than the Food and Drug Administration. Consequently, supplements do not need to meet the standards for safety and efficacy required for marketing of pharmaceuticals.
Elevated low-density lipoprotein (LDL), also known as bad cholesterol, is a major cause of coronary heart disease. LDL cholesterol causes the build-up of fatty deposits within the arteries, reducing or blocking the flow of blood and oxygen the heart needs. This can lead to heart attack or stroke. Many studies show that lowering LDL cholesterol reduces the risk for coronary heart disease.
In the single-center, prospective, randomized, single-blind clinical trial, researchers analyzed health data for 190 adults between the ages of 40 and 75 with no history of cardiovascular disease. The participants were randomized to a low-dose statin medication rosuvastatin (5 mg daily), placebo, fish oil, cinnamon, garlic, turmeric, plant sterols or red yeast rice. The primary endpoint was the percent change in LDL cholesterol from baseline for rosuvastatin 5 mg daily compared with placebo and each supplement after 28 days.
Results showed that the percent LDL cholesterol reduction with rosuvastatin was greater than all supplements and placebo. None of the dietary supplements demonstrated any significant decrease in LDL cholesterol compared with placebo. Rosuvastatin also had beneficial impact on blood triglycerides and total cholesterol, which help reduce cardiovascular risk.
Average LDL cholesterol reduction after 28 days was 37.9% among participants who took the statin, while changes in LDL cholesterol levels among those who took any of the dietary supplements were similar to those in the placebo group. The participants in the statin group had an average 24% decrease in total cholesterol, while both the placebo group and all dietary supplements showed no benefit. Rosuvastatin resulted in a 19% decrease in blood triglycerides compared with placebo, but there was no difference in triglycerides for any of the dietary supplements.
Rates of adverse events were similar across all groups, although numerically higher among participants randomized to plant sterols or red yeast rice. Also, no significant adverse changes in liver function testing, estimated glomerular filtration rate, or blood glucose were observed with the use of rosuvastatin.
“Dietary supplement sales are estimated at nearly $50 billion annually in the United States and many supplements are marketed as natural alternatives for heart protection and cholesterol management,” said senior author Steven Nissen, M.D., Chief Academic Officer of the Heart, Vascular & Thoracic Institute at Cleveland Clinic. “For management of high cholesterol, supplements are often used by patients in place of statins, in the absence of high-quality data. This represents a major public health concern.”
The SPORT Trial was funded by AstraZeneca with an unrestricted grant. Cleveland Clinic has full control over the study methodology, data analysis, and discussion of clinical implications.
Dr. Laffin has served as a consultant or steering committee member for Medtronic, Eli Lilly, Mineralys Therapeutics, AstraZeneca. He is an advisor for LucidAct Health and Gordy Health.
Dr. Nissen has served as a consultant for many pharmaceutical companies and has overseen clinical trials for Amgen, AstraZeneca, Cerenis, Eli Lilly, Novartis, Novo Nordisk, The Medicines Company, Orexigen, Takeda and Pfizer. However, he does not accept honoraria, consulting fees or other compensation from commercial entities.