Heart-health supplements ineffective at reducing bad cholesterol
A new study is offering more evidence expensive vitamin supplements may be a waste of money, finding six common heart-health formulations are ineffective at reducing cholesterol levels or markers of inflammation. Cardiovascular experts say patients should not replace prescribed medications with these over-the-counter supplements.
“According to a 2020 market research analysis, Americans spend an estimated US$50 billion on dietary supplements annually, and many are marketed for ‘heart protection’ or ‘cholesterol management’," said Luke Laffin, an author on the new study. "Yet there is minimal-to-no research demonstrating these benefits."
To investigate the effectiveness of these supplements, the researchers recruited nearly 200 participants with no history of cardiovascular disease. All subjects were screened for low-density lipoprotein (LDL) cholesterol, and included in the trial if their levels were slightly above a healthy average.
The cohort was split into eight groups: placebo, low-dose statin (rosuvastatin), or one of six common dietary supplements branded for improving heart health. The supplements included a fish oil formulation, a turmeric supplement, a garlic-based supplement, and a supplement blending a variety of plant sterols.
After the 28-day study period the researchers saw an average drop in LDL levels of 37.9% in the statin group. Any changes in LDL levels for the supplement groups were comparable to those taking placebo.
The statin group also saw a 19% drop in triglyceride levels. Again, no difference was detected in triglycerides between placebo and supplement groups.
Interestingly, compared to placebo, the study saw a notable drop in high-density lipoprotein (HDL) cholesterol levels in the group taking the plant sterols supplement. HDL cholesterol is informally known as the "good" cholesterol as it helps protect heart health by removing other forms of cholesterol from the bloodstream.
The study also unexpectedly saw LDL levels increase in those taking the garlic supplements, compared to placebo. The researchers do not claim the supplement is responsible for the cholesterol increase but instead suggest the findings affirm how inconsistent the effects of these supplements can be.
“Although there are prior studies demonstrating that red yeast rice and plant sterol supplements may reduce LDL cholesterol, the findings of our study underscore that the contents of these dietary supplements may vary," added Laffin. "Therefore, they do not produce consistent reductions in cholesterol."
It's important to note the study was funded by pharmaceutical company AstraZeneca, which makes the statin rosuvastatin. The researchers are clear the company had no input into the study design or framing of the results, however, dietary supplement lobby group the Council for Responsible Nutrition (CRN), has already taken aim at the study, claiming it looks like it was, "was set up for misdirection and failure of the supplements."
CRN vice president Andrea Wong said in a statement that dietary supplements are not "quick-fix" pills, and a four-week trial period would never capture the full range of benefits from supplements. Wang also questioned the study's focus on lowering LDL cholesterol as the primary endpoint since heart-health supplements often focus on broader systemic health benefits over longer periods of time.
"While all the supplements included in the study are well-recognized for their benefits related to heart health, only three are marketed for their cholesterol lowering benefits," said Wang. "The other ingredients are better known for their effects on other health outcomes (like improvement of triglycerides or insulin modulation), so it is unclear why they were chosen to be assessed for their effects on LDL cholesterol."
Speaking to CNN, Amit Khera, chair of the American Heart Association Scientific Sessions conference programming committee, said he thought the research was important enough to include in their recent conference. Khera, a working cardiologist at UT Southwestern Medical Center, said patients can take these supplements in lieu of statins thinking they will help with lowering cholesterol.
“I take care of patients every day with these exact questions," said Khera, who did not work on the new study. "Patients always ask about the supplements in lieu of or in addition to statins. I think if you have high quality evidence and a well done study it is really critical to help inform patients about the value, or in this case the lack of value, for some of these supplements for cholesterol lowering.”
The study was published in the Journal of the American College of Cardiology.
Source: American Heart Association