Cholesterol-Lowering Supplements: What Works, What Doesn't

Fish oil

• What it is: Fish is rich in two heart-healthy omega-3 fatty acids, EPA and DPA. In concentrated form, these fatty acids are the main ingredients in fish oil supplements, which are usually sold as gel capsules.

• The evidence: In clinical trials using relatively high doses (3 grams or more), fish oil has been shown to lower triglyceride levels—the third component of your total cholesterol number—by around 10% to 30%. (The higher your triglyceride levels, the more effective it is.) Fish oil doesn’t lower LDL, however. The supplements actually tend to cause a slight rise in LDL, although the form this additional LDL takes is thought to be less damaging to the arteries.

High triglyceride levels have been associated with an increased risk of coronary heart disease, but lowering them is not as important as lowering LDL. In fact, some experts believe that triglycerides are a sign, rather than a cause, of heart disease risk.

• The bottom line: Fish oil lowers triglycerides, especially in people with high triglycerides. The American Heart Association recommends that people who need to lower their triglycerides should, in consultation with their doctor, take 2 to 4 grams of fish oil a day; people with heart disease should consume about 1 gram a day of EPA and DPA (combined), preferably by eating fatty fish such as salmon.

Garlic

• What it is: Garlic is member of the onion family that is available as an oil, extract, or pill (in addition to its natural state).

• The evidence: In a 2000 report on garlic’s impact on cardiovascular risk factors, the federal Agency for Healthcare Research and Quality found that garlic caused a small but measurable drop in both LDL and total cholesterol, but only in the short term (three months).

Subsequent research hasn’t been encouraging, however. A high-quality 2007 study in the Archives of Internal Medicine compared raw garlic and commercial garlic supplements over a six-month period and found no measurable effects of the various garlic forms on total cholesterol, LDL, HDL, or triglyceride levels versus placebo. The following year, a meta-analysis that included only randomized, placebo-controlled trials also concluded that garlic has no effect on cholesterol.

• The bottom line: Though garlic may help lower LDL temporarily, its ability to meaningfully affect cholesterol levels is questionable at best.

Ginseng

• What it is: Ginseng is an herb native to Asia that has been used in traditional medicine for centuries and is now sold as capsules.

• The evidence: The research on ginseng and cholesterol is mixed but unconvincing. In a comprehensive 2005 review, a team of Harvard Medical School researchers noted that several studies had found a beneficial effect from ginseng on one or more cholesterol components. But most of the studies were small, only a few were randomized, and none were blinded or placebo-controlled. In one study, the researchers found a drop of 45% in LDL levels and a rise in HDL of 44%—but it wasn’t controlled, included only eight participants, and was funded by a Korean manufacturer of ginseng products.

• The bottom line: Though the results of the nonrandomized studies can’t be ignored, there isn’t enough to evidence to support the use of ginseng to lower cholesterol.

Guggul

• What it is: A tree-resin extract, long used in Ayurvedic medicine, guggul contains plant sterols (guggulsterones) and is available in capsule form.

• The evidence: As with ginseng, the research on guggul and cholesterol is sketchy. Early studies reported reductions in total cholesterol, LDL, and triglycerides of 10% or more, but most of the studies were small and flawed. Then, in 2003, researchers at the University of Pennsylvania published a randomized controlled trial of more than 100 people with high cholesterol—the first guggul study conducted in the U.S.—in the Journal of the American Medical Association. They found that guggul had no measurable effect on total cholesterol, HDL, or triglycerides—and that it caused an increase in LDL of about 5%. (LDL levels in the placebo group fell by roughly the same amount.)

• The bottom line: The 2003 JAMA study was a black eye for guggul. More research is needed, but for now there is not enough evidence to justify using guggul to lower cholesterol. Plus, some research has found that 20% of Ayurvedic medicines may be contaminated with lead or other toxins.