Study Refutes Heart Health Claims of Dietary Supplements

CHICAGO -- For people without heart disease, preventive low-dose statin therapy lowered LDL cholesterol to a degree that dietary supplements and placebo couldn't match, a randomized trial found.

People taking rosuvastatin 5 mg per day for 4 weeks had an average 37.9% reduction in LDL cholesterol, the only group to do better than the placebo arm in a study that also had comparator groups taking fish oil, cinnamon, garlic, turmeric, plant sterols, or red yeast rice (P<0.001 for all comparisons).

In fact, the study's worst performer, a garlic supplement, increased LDL cholesterol by 7.8% over placebo (P=0.01), according to Luke Laffin, MD, of the Cleveland Clinic, who presented the SPORT trial at the American Heart Association (AHA) annual meeting. The findings were published simultaneously in the Journal of the American College of Cardiology.

He urged cardiologists, primary care physicians, and others to use the SPORT trial results in evidence-based discussions with their patients who need to lower LDL cholesterol. To provide reassurance, he pointed to the lack of excess side effects -- gastrointestinal, musculoskeletal, or neurological -- among statin users in the study.

These SPORT trial results come at a time when statins and other prescription heart drugs struggle to gain acceptance among patients despite strong evidence for their cardiovascular benefits.

Meanwhile, dietary supplements marketed for "heart health" are ubiquitous and immensely popular. Laffin said it's not uncommon to see patients taking 10-20 supplements, and many people prescribed a cholesterol-lowering medication opt to "go down the aisle" and take a supplement instead.

"This study sends an important public health message that dietary supplements commonly taken for 'cholesterol health' or 'heart health' are unlikely to offer meaningful impact on cholesterol levels," he said in a press release.

And the lack of benefit is not the only problem with these supplements.

"The supplement industry is practically an unregulated $50 billion industry," said Janani Rangaswami, MD, of George Washington University School of Medicine in Washington, during an AHA press conference. She warned that no one really knows what supplement manufacturers put in their products, and that she has personally observed supplement-induced kidney injury in her nephrology practice.

According to Laffin, another problem with not knowing what's in a dietary supplement is the potential for harmful drug-drug-interactions that may occur in people taking dietary supplements alongside their regular medications. There is just not enough safety information on the 90,000 supplements on the market today, he suggested.

Amit Khera, MD, of UT Southwestern Medical Center in Dallas, acknowledged that patients may take dietary supplements for a variety of reasons. Turmeric, for example, is promoted for arthritis, digestive disorders, respiratory infections, allergies, liver disease, and depression.

Now it can be said that taking these supplements instead of statins just to lower cholesterol, however, is definitively unhelpful and could cause harm, he emphasized.

SPORT was a single-blind trial that enrolled 199 patients across the Cleveland Clinic Health System. Participants were required to be off statins, other prescription lipid-lowering therapy, and any of the tested supplements before entering the study. All had LDL cholesterol in the 70-189 mg/dL range and no history of atherosclerotic cardiovascular disease.

Laffin reported that beyond LDL cholesterol lowering, rosuvastatin outperformed fish oil, cinnamon, garlic, turmeric, plant sterols, and red yeast rice in reducing total cholesterol and triglycerides.

Just like these supplements, however, the statin conferred no change in inflammation.

The investigators acknowledged that their study had limited statistical power to detect small benefits, if any, to the dietary supplements.

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