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  • A new study found that six dietary supplements commonly marketed as a way to lower cholesterol had no significant impact on levels of LDL cholesterol.
  • People in the study who took a low-dose prescription medication known as a statin saw a 35% average drop in their LDL cholesterol levels during that time.
  • The US Preventive Services Task Force recommends statins for adults aged 40 to 75 years with certain risk factors for cardiovascular disease.

If you’ve been thinking about trying to lower your cholesterol using over-the-counter dietary supplements instead of a prescription medication, you may want to hold off on that.

A new study found that six dietary supplements commonly marketed as a way to lower cholesterol had no significant impact on levels of LDL (low-density lipoprotein) cholesterol, sometimes called “bad” cholesterol, compared to an inactive placebo.

The supplements tested in the study over a 28-day period were fish oil, garlic, cinnamon, turmeric, plant sterols, and red yeast rice.

In contrast, people in the study who took a low-dose prescription medication known as a statin saw a 35% average drop in their LDL cholesterol levels during that time.

“Compared with placebo, the only agent — of those tested in the study — that actually lowered LDL cholesterol was the statin medication,” said Dr. Kershaw Patel, a preventive cardiologist and assistant professor of cardiology at Houston Methodist in Texas.

“So the take-home message for me is patients should not waste their money on these dietary supplements in order to lower their LDL cholesterol,” he said.

Patel was not involved in the new study, which was published November 6 in the Journal of the American College of Cardiology.

The study was funded by AstraZeneca BioPharmaceuticals, manufacturer of Crestor, a brand name version of the statin used in this study.

Cholesterol is a waxy, fat-like substance made by the liver that circulates in the blood. The body uses cholesterol to make certain hormones and help digest fatty foods.

Animal foods, including meat, poultry, eggs, seafood, and dairy products also contain cholesterol.

Having too much LDL cholesterol, along with too many triglycerides, in your blood can increase the risk of heart attack and stroke.

The US Preventive Services Task Force recommends statins for adults aged 40 to 75 years with certain risk factors for cardiovascular disease.

However, one survey found that only 45% of Americans over 40 years of age who were eligible for a statin actually took this medication.

Patel said people may avoid taking a statin because they are concerned about the safety of these prescription medications. What they may not realize, though, is “the safety of dietary supplements are not evaluated with the same rigor as prescription medications,” he added.

Dr. Lawrence Appel, a professor of medicine and director of the Welch Center for Prevention, Epidemiology and Clinical Research at The Johns Hopkins University in Baltimore, said consumers are also “bombarded with commercials and advertisements telling them to consume these supplements … for really fuzzy reasons.”

However, “there’s really no compelling biological rationale why any of these supplements would dramatically lower LDL cholesterol,” he added. “I mean there’s just no basis for it.”

In the recent study, 190 people between the ages of 40 and 75 were randomly assigned to take the low-dose rosuvastatin, one of the six dietary supplements or an inactive placebo for 28 days.

Those who took the statin saw a 35% decrease in LDL cholesterol compared to the placebo group. People taking the statin also had a larger decrease in total cholesterol and triglycerides than the placebo group.

People taking one of the supplements or the placebo, however, saw no significant benefit over the course of the 28 days.

In addition, people taking the garlic supplement saw their LDL cholesterol increase by almost 8%.

The rates of adverse events were similar for all groups, researchers found.

Statins can cause side effects such as muscle pain, constipation, and diarrhea. However, in 2018 the American Heart Association said in a scientific statement that for people for who statin treatment is recommended, the benefits “greatly outweigh” the risks.

Although dietary supplements are sometimes marketed as “natural,” they may not always be safe, especially when people are taking other supplements or medications.

In addition, the industry is largely unregulated, so the quality of products and ingredients can vary among manufacturers, said Dr. Efstathia Andrikopoulou, a cardiologist and assistant professor of medicine at the University of Alabama at Birmingham.

As a result, “there can be unpredicted drug-to-drug interactions between supplements and other over-the-counter or prescription medications,” she said. In fact, “some of us [physicians] have had patients who developed kidney disease after taking dietary supplements.”

Patel said one of the limitations of the study is that researchers did not follow people longer than 28 days. So it’s unknown if LDL cholesterol levels would drop more in people taking one of the dietary supplements for a longer time.

Still, statins typically start to work within about a month, he said, “so I think if we were going to see any change, it would happen during this time.”

The Council for Responsible Nutrition, a trade association for the dietary supplement industry, released a statement November 6 in response to the study, saying, “dietary supplements are not intended to be quick fixes and their effects may not be revealed during the course of a study that only spans four weeks, particularly on a multifactorial condition like high cholesterol.”

“Even more perplexing is the researchers’ selection of the supplements in the study,” the council said in their statement. “It’s as if the study was set up for misdirection and failure of the supplements. 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.”

Some research supports the longer-term impact of certain dietary supplements.

One review of previous studies found that people taking krill oil — which contains similar omega-3 fatty acids as fish oil — saw a larger drop in LDL cholesterol when they used this dietary supplement for more than 12 weeks.

However, some reviews of previous research have found no effect of fish oil on total or LDL cholesterol levels in people with type 2 diabetes. There were some beneficial changes in HDL cholesterol and triglycerides.

Patel said one of the problems with waiting longer to lower your cholesterol is that you are exposed to cardiovascular-related risks for a longer period. Statins, though, start lowering LDL cholesterol in as little as a few weeks.

Rather than dietary supplements, Patel recommends that people improve their diet quality — which has nothing to do with supplements, he said — and talk to their doctor about taking a cholesterol-lowering medication.

Andrikopoulou said the recent study highlights that there is no value in taking these six dietary supplements for improving cholesterol levels.

In addition, “this [study] reinforces our already established dietary and lifestyle recommendations that encourage everyone to make sure they get their vitamins and nutrients from consumption of heart-healthy foods, such as minimally processed foods, vegetables, fruits, lean proteins, and whole grains,” she said.

In particular, Patel encourages patients to eat a Mediterranean diet, which emphasizes vegetables, fruits, whole grains, beans, and legumes and includes heart-healthy oils such as olive oil.

The American Heart Association also recommends DASH, or Dietary Approaches to Stop Hypertension, which allows more dairy products and meat than the Mediterranean diet. Other alternatives are plant-based vegetarian or vegan diets.

While there are heart-healthy diets, eating a diet low in cholesterol does not mean you will have low cholesterol and the same is true for high-cholesterol foods. The body regulates how much cholesterol is in the body and will sometimes make more or less depending on how much cholesterol is taken in via diet.

With all these diets, it is important to limit the intake of saturated fats, added sugars, and highly processed foods.

Andrikopoulou also recommends that people get at least 150 minutes a week of moderate-intensity physical activity.