Dietary Supplements Hyped as LDL-Lowering Are a Bust: SPORT

November 07, 2022

None of six commercial dietary supplements widely promoted and taken for lowering low-density lipoprotein (LDL) cholesterol did the job any better than placebo in a randomized trial of adults without cardiovascular disease but at increased cardiovascular risk.

In contrast, those who took the low dose of a high-potency statin in the eight-arm comparative study showed a significant 38% drop in LDL cholesterol levels over 28 days, a performance that blew away the six supplements containing fish oil, cinnamon, garlic, turmeric, plant sterols, or red yeast rice.

The supplements showed little or no effect on any measured lipid biomarkers, which also included total cholesterol and triglycerides, or C-reactive protein (CRP), which reflects systemic inflammation.

The findings undercut the widespread heart-health marketing claims for such supplements and could potentially restore faith in statins for the many patients looking for alternatives, researchers say.

"We all see patients that have their medication lists littered with dietary supplements," observed Luke J. Laffin, MD, Cleveland Clinic Foundation. And it's more than just heart patients who use them.

Almost $50 billion is spent on dietary supplements annually in the United States, and recent data suggest that more than three fourths of the population use them, 18% of those based on specious heart-health claims, said Laffin in a November 6 presentation at American Heart Association (AHA) Scientific Sessions 2022, held in Chicago and virtually.

The findings of the Supplements, Placebo, or Rosuvastatin Study (SPORT) and how they are framed for the public "are important for public health," he said.

"As cardiologists, primary care doctors, and others, we really should use these results to have evidence-based discussions with patients" regarding the value of even low-dose statins and the supplements' "lack of benefit," said Laffin, who is also lead author on the SPORT publication, which was published the same day in the Journal of the American College of Cardiology.

Patients assigned to low-dose rosuvastatin showed a mean 24.4% drop in total cholesterol levels over 28 days, the study's primary endpoint. That differed from the placebo group and those for each supplement at P < .001.

They also averaged a 19.2% decrease in serum triglycerides, P < .05 for all group comparisons. None of the six supplements was significantly different from placebo for change in levels of either total cholesterol or triglycerides.

Nor were there significant differences in adverse events across the groups; there were no adverse changes in liver or kidney function tests or glucose levels; and there were no signs of musculoskeletal symptoms, the published report notes.

How to Message the Results

The SPORT trial is valuable for "addressing the void of data on supplements and cardiovascular health," Chiadi E. Ndumele, MD, PhD, MHS, Johns Hopkins University, Baltimore, Maryland, said as invited discussant following Laffin's presentation.

But they also send a reassuring message about statins, he noted. In a recent study of statin-nonadherent patients, 80% "were worried about statin side effects as the primary reason for not taking their statin, and 72% preferred using natural supplements instead of taking their prescription therapy," Ndumele said. "The reason for this is clearly mistrust, misinformation, and a lack of evidence."

The next step, he proposed, should be to get the study's positive message about statins to the public, and especially patients "who are hesitant about statin use." The current study "underscores the fact that using a low dose of a high-potency statin is associated with a very, very low risk of side effects."

At a media briefing on SPORT, Amit Khera, MD, agreed the randomized trial provides some needed evidence that can be discussed with patients. "If someone's coming to see me for cholesterol, we can say definitively now, at least there is data that these [supplements] don't help your cholesterol and statins do." Khera directs the preventive cardiology program at University of Texas Southwestern Medical Center, Dallas.

"I think for those who are there very specifically to lower their cholesterol, hopefully this will resonate," he said.

"I personally didn't see a lot of harms in using these supplements. But I also didn't see any benefits," Khera told | Medscape Cardiology.

"Now, if you're taking them for other reasons, so be it. But if you need to lower your cholesterol for cardiovascular health reasons," he said, "you need to know that they are minimally to not effective at all."

But such supplements still "are not without harm," Laffin proposed at the press conference. For example, they have potential for drug–drug interactions, "not only with cardiovascular medicines, but those taken for other reasons," he said. "There are 90,000 supplements on the market in the United States today, and there are all kinds of potential safety issues associated with them."

In patient discussions, Laffin said, "I do not think it's good enough to say, you can waste your money [on supplements] as long as you're taking your statin. These can actually be harmful in certain situations."

SPORT, described as a single-center study, randomly assigned 199 participants from "throughout the Cleveland Clinic Health System in northeast Ohio" to one of the eight treatment groups. The investigators were blinded to treatment assignments, Laffin reported.

High Adherence

Entry criteria included age 40 to 75 years with no history of cardiovascular disease, LDL-cholesterol from 70 to 189 mg/dL, and a 5% to 20% 10-year risk of atherosclerotic cardiovascular disease by the pooled cohort equations. The predominantly White cohort averaged 64.4 years in age and 59% were women.

They were assigned to receive rosuvastatin 5 mg daily, placebo, or daily doses of supplements, with 25 patients per group, except the fish-oil group, which included 24 patients.

The daily supplement dosages were 2400 mg for fish oil (Nature Made); 2400 mg for cinnamon (NutriFlair), 5000 mcg allicin for the garlic (Garlique), 4500 mg for turmeric curcumin (BioSchwartz), 1600 mg plant sterols (CholestOff Plus, Nature Made), and 2400 mg red yeast rice (Arazo Nutrition).

Adherence to the assigned regimens was high, Laffin said, given that only four participants took less than 70% of their assigned doses.

Levels of LDL cholesterol in the statin group fell by 37.9% in 28 days, and by 35.2% relative to the placebo group (P < .001 for both differences), whereas any changes in LDL cholesterol among patients taking the most supplements were not significantly different from the placebo group. Of note, LDL cholesterol levels rose 7.8% (P = .01) compared with placebo among the group assigned to the garlic supplement.

Rosuvastatin had no apparent effect on HDL cholesterol levels, nor did most of the supplements; but such levels in patients taking the plant sterol supplement decreased by 7.1% (P = .02) compared to placebo and by 4% (P = .01) compared to the statin group.

None of the non-control groups, including those assigned to rosuvastatin, showed significant changes in high-sensitivity CRP levels compared with the placebo group. The lack of rosuvastatin effect on the inflammatory biomarker, the researchers speculate, is probably explained by the statins' low dose as well as the limited size of the trial population.

There were two serious adverse events, including one deep venous thrombosis in the placebo group and a liver adenocarcinoma in a patient assigned to fish oil who "had not yet taken any of the study drug at the time of the serious adverse event," the published report notes.

It remains open whether any of the assigned regimens could show different results over the long term, Laffin said. The SPORT trial's 28-day duration, he said, "may not have fully captured the impact of supplements on lipid and inflammatory biomarkers."

Nor is it known whether the supplements can potentially affect clinical outcomes. But "you could make an argument that it would be unethical" to randomize similar patients to a placebo-controlled, cardiovascular outcomes trial comparing the same six supplements and a statin.

Laffin has disclosed consulting or serving on a steering committee for Medtronic, Lilly, Mineralys Therapeutics, AstraZeneca, and Crispr Therapeutics; receiving research funding from AstraZeneca; and having ownership interest in LucidAct Health and Gordy Health. Ndumele and Khera have reported no relevant financial relationships.

American Heart Association Scientific Sessions 2022. Abstract LBS.05. Presented November 6, 2022.

J Am Coll Cardiol. Published online November 6, 2022.  Full text

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