But which supplements -- if any -- actually work, and which are useless? Researchers continue to search for answers to that question, but some supplements have been found to have cholesterol-lowering benefits.
Regardless of which supplements you may choose to try, it's always wise to talk with your doctor first. Even "all-natural," herbal supplements contain active compounds that can interact with other medication, notes Daniel Edmundowicz, MD, associate professor of medicine and director of preventive cardiology at the University of Pittsburgh Medical Center.
"If people have high cholesterol levels and they need to lower their cholesterol, they should not be dependent on supplements to reach their cholesterol goals," Dr. Edmundowicz cautions. Because supplements aren't regulated, they can vary widely in purity and efficacy.
Fish and Fish Oil
"I love fish oils, says Lynne Shinto, MPH, a naturopathic doctor and assistant professor at Oregon Health and Science University in Portland. "As a clinician, I use fish oil for a lot of different things, mostly due to its anti-inflammatory properties," she says.
Dr. Edmundowicz agrees, noting that fish oil and its constituent omega-3 fatty acids have been used for many years to lower triglyceride levels. The American Heart Association (AHA) recommends eating fish high in omega-3 fatty acids, such as mackerel, albacore, tuna and salmon, at least twice a week.
High levels of omega-3 fatty acids, however, can contribute to excessive bleeding in some people, so caution is advised.
Although many people say they believe "the stinking rose" is a proven treatment for high cholesterol, medical evidence of this position is negligible and inconsistent. The advice of most experts: save your breath.
A small amount of anecdotal evidence supports the use of this popular Indian spice to improve cholesterol levels. Curcumin is the biologically active part of turmeric, and it seems to work mostly as an antioxidant -- not as a cholesterol treatment. "We don't pull that off the shelf for cardiovascular health," says Dr. Edmundowicz.
Soy products, such as tofu and soy milk, have been linked to a range of health benefits, including reducing high cholesterol levels, but soy's cholesterol benefits are still unproven. Many experts believe it's not the soy itself, but soy's superiority to other higher-fat sources of protein that makes it effective at lowering cholesterol levels. "The bottom line is, when folks shift from milk to soy milk, they're decreasing their intake of saturated fats," Dr. Edmundowicz says. It isn't drinking soy milk that is directly lowering cholesterol: it is not drinking cow's milk.
Plant Stanols/Plant Sterols
Plant stanols and sterols -- collectively known as phytosterols -- are found in nuts, fruits, vegetables, vegetable oils, legumes, seeds and cereals. The food industry sometimes adds them to fat-containing products, such as salad dressing, yogurt and margarine.
There is some disagreement over how effective these are at improving cholesterol levels, and there are some safety concerns. The American Heart Association does not recommend these products for the general public, but the National Cholesterol Education/Adult Treatment III program guidelines do recommend them in heart-healthy dietary plans.
A claim that plant sterol esters can help reduce the risk of heart disease has been okayed by the Food and Drug Administration.
Red Yeast Rice
Red yeast rice wins near-unanimous approval among experts for its ability to improve cholesterol levels. Because this fermented rice product is chemically similar to a statin, Dr. Edmundowicz says, "It's a low-dose statin. I call it 'statin-equivalent.'"
In fact, one of the compounds in red yeast rice, monacolin K, is the active ingredient in lovastatin, marketed as Mevacor. Since monacolin K is found in small quantities in red yeast rice, though, some researchers speculate that there may be additional compounds in this supplement that make it so effective. And, as Shinto points out, red yeast rice is fairly inexpensive.
It should be noted, though, that the FDA has ruled that red yeast rice containing lovastatin is a regulated product that must be removed from the shelves, so the red yeast rice now available in the United States may not effectively reduce cholesterol levels any longer. Either way, since its original form is so similar to statins, the same precautions would apply if you are going to consume them: Pregnant women and patients with liver conditions, for example, should use red yeast rice only under the supervision of a doctor.
"I thought guggulipid was gonna be a home run just based on its name," quips Dr. Edmundowicz, "but the science supporting the use of this extract of myrrh-tree resin is just not there."
Although tea, including green tea, has been associated with a drop in cholesterol levels, "it's not a huge drop," says Dr. Edmundowicz. "I really can't give [tea] a thumbs-up."
Niacin, vitamin B3, is known to both increase levels of HDL (high-density lipoproteins, "good" cholesterol) and lower LDL (low-density lipoproteins, "bad" cholesterol). Niacin, however, can cause uncomfortable skin flushing and other side effects. At high doses, elevation in levels of some liver enzymes, which can indicate potential damage to the liver, is sometimes seen. "Some people tolerate it well, and some don't," says Shinto.
These and other supplements will have different effects on different people. Shinto joins other experts in advising a conservative approach to their use. "If cholesterol levels don't change after three months [of trying a supplement as a cholesterol therapy], I recommend they talk to their primary care physician about going on statins," she says.
"Association Releases New Diet and Lifestyle Recommendations." Americanheart.org. 20 Jun. 2006. American Heart Association. 15 Sep. 2008 <http://www.americanheart.org/presenter.jhtml?identifier=851>.
Daniel Edmundowicz, University of Pittsburgh Medical Center. Telephone interview, 16 Sep. 2008.
"Fish and Omega-3 Fatty Acids." Americanheart.org. 2008. American Heart Association. 15 Sep. 2008. <http://www.americanheart.org/presenter.jhtml?identifier=4632>.
"Garlic (Allium sativum L.)." Nlm.nih.gov. 1 Feb. 2008. National Institutes of Health. 14 Sep. 2008 <http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-garlic.html>.
Lynne Shinto, Oregon Health and Science University. Telephone interview, 16 Sep. 2008.