/publications/issue/2009/December2009/PEDietarySupplements-1209

Dietary Supplements and Heart Health

Author: Kyle R. Copeland, PharmD

Dr. Copeland is a clinical pharmacist specialist at Parkwest Medical Center Pharmacy in Knoxville, Tennessee.


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In 2005, more than 650,000 people died from heart disease, accounting for 27% of the deaths in the United States, making it the leading cause of death for both men and women in the United States. The development of cardiovascular disease is very complicated, and it is affected by multiple factors, including elevated cholesterol and tri glycerides, coagulation factors, platelet aggregation, glucose metabolism, and smoking. Studies have shown that lowering high cholesterol and high blood pressure can reduce the risk of developing heart disease. To maintain good “heart health,” the combination of a good diet, exercise, and no smoking is essential. For patients who need additional therapy beyond lifestyle modifications, doctorprescribed medications are available and some dietary supplements may be considered. This article will review some of the most common supplements used to improve heart health. As with any over-the-counter products, it is very important to check with your physician before you begin taking any supplements as well as telling them of any you are currently using.

Omega-3 Fatty Acids

In the late 1970s, Danish physicians Jorn Dyerberg and Hans Olaf Bang observed that Greenland Eskimos had a lower rate of death from heart disease compared with Americans and Danes. After researching this finding, they noted that the Greenland Eskimos consumed a diet rich in omega-3 fatty acids.

Results from several clinical trials support the beneficial effects of omega-3 fatty acids on the cardiovascular system. There is good evidence supporting the conclusion that omega-3 fatty acids from fish or fish oil supplements significantly reduce triglyceride levels. They also may cause small improvements in high-density lipoprotein (HDL; “good cholesterol”). Increased levels of low-density lipoprotein (LDL; “bad cholesterol”) were also seen, however. Multiple studies report a reduction in secondary events associated with cardiovascular disease, including reductions in nonfatal and fatal heart attacks and sudden cardiac (heartrelated) death. It is important to note that patients in these trials were also taking prescription drugs for the heart and were being routinely evaluated by a physician.

The most significant side effect associated with omega-3 fatty acids is bleeding, although this is seen more often with excessive use. Patients who are also taking any medication that may thin the blood should check with their primary care provider before beginning any regular supplementation with omega-3 fatty acids. Upset stomach, diarrhea, and nausea were also common with the use of fish oil supplements.

The American Heart Association (AHA) has released recommendations for the use of omega-3 fatty acids for the treatment of elevated triglyceride levels. For patients without coronary heart disease, the AHA recommends eating fish at least twice a week. For patients with coronary heart disease, the AHA recommends consumption of about 1 gram per day of omega-3 fatty acids. These patients may consider using supplements, such as fish oils. For patients who need to significantly lower triglyceride levels, supplementation with 2 to 4 grams per day of fish oil is recommended.

Lastly, vitamin E is essential for the metabolism of omega-3 fatty acids, and with long-term use of fish oil supplements, extra vitamin E is needed. Because of this, many fish oil supplements contain additional amounts of vitamin E.

Plant Sterols

Throughout history, plants have been eaten as a part of a regular diet. In fact, early human diets were very rich in phytosterols. Phytosterols are naturally occurring compounds from plants and are found in vegetable oils. These compounds have a similar natural function in plants that cholesterol has in humans and other mammals. When eaten, approximately 50% of dietary cholesterol is absorbed, while less than 10% of dietary phytosterols are absorbed.

Plant sterols have been shown to decrease total cholesterol by up to 13% and LDL up to 16% if at least 2 grams per day are ingested as part of a healthy diet. With the addition of exercise, specifically endurance training, these numbers can be even higher. The lowest dose to show beneficial effect was 0.8 to 1 gram per day, which was associated with a reduction in LDL of approximately 5%.

The most common complaints are nausea, indigestion, diarrhea, and constipation. Plant sterols were also shown to have a small, but significant effect on absorption of vitamins D3 and E.

The Food and Drug Administration has authorized the health claim that regular consumption of foods with plant sterols may reduce the risk of heart disease. To prevent vitamin deficiencies, a diet rich in fruits and vegetables (at least 5 servings per day) is recommended in addition to any supplementation with plant sterols.

Garlic

Garlic is one of the oldest recorded remedies used to treat disease. There are biblical references to garlic for sustaining strength during hard labor. The use of garlic was also recorded in the Codex Ebers, a 3500-year-old Egyptian document, where it was described for the treatment of heart disease, tumors, and other ailments. In recent clinical trials, the most important effects of garlic are those of mild reductions in cholesterol and reduced platelet clotting.

The decrease in platelet clotting leads to its most common side effect, bleeding. Other side effects include asthma flares, dizziness, sweating, bad breath, body odor, headache, itching, fever, chills, and runny nose. The current recommended dose for garlic supplementation is 200 to 300 mg of garlic extract 3 times a day (600- 900 mg/day). If taken as part of the diet, 2 to 5 grams of fresh garlic is recommended daily.

Although garlic certainly has a place in reducing the risk of cardiovascular disease, further studies are needed to provide a clearer understanding of its place in therapy.

Coenzyme Q10

Coenzyme Q10 (CoQ10) is a substance produced by the human body that is necessary for the normal function of cells. It has been noted that levels of CoQ10 decrease with age and are lower in some patients with chronic conditions such as cardiovascular disease. There is a lot of controversy surrounding the use of CoQ10 supplements. The only clear indication is in patients who do not have enough CoQ10. Other promising areas of research include blood pressure and some other heart conditions.

Early research has shown that CoQ10 supplementation may result in small but significant reductions in blood pressure. The primary effects were seen with systolic blood pressure (the higher number) with minor effects on diastolic blood pressure (the lower number). CoQ10 supplementation has been studied in numerous other heart conditions, but not enough evidence exists to recommend for, or against, its use. The recommended dose ranges from 50 to 1200 mg/day in divided doses.

Few side effects have been noted and include nausea, vomiting, rash, insomnia, headache, and flu-like symptoms. Organ damage due to lack of oxygen and blood flow has been noted in patients with heart disease during vigorous exercise. Additionally, CoQ10 supplementation may reduce the effectiveness of warfarin (Coumadin), a blood-thinning medication. It may also affect thyroid hormone levels and change your response to levothyroxine (Synthroid). Finally, CoQ10 may interact with antiviral medications and some medications used to treat HIV.

Summary

The cornerstone of any effort made for the prevention of heart disease is eating healthy, exercising, and not smoking. In fact, quitting smoking is the single most important factor patients can change to reduce the risk of developing or worsening heart disease. The AHA recommends that healthy people get their nutrients by eating a variety of foods, in moderation, rather than by taking supplements. Emphasis should be placed on fruits, vegetables, and whole grains. In nonsmoking patients with a healthy diet who ex - ercise regularly, supplementation with certain substances, especially omega-3 fatty acids, can be associated with reductions in cardiovascular disease. Most importantly, a physician should be consulted prior to beginning any supplement, especially for those patients with known heart disease or who are already taking prescription drugs.