This antioxidant is used to treat heart problems, diabetes, migraines, and other conditions?and may even reduce signs of aging

By Victoria Dolby Toews, MPH

What it is
Coenzyme Q10 is a vitamin-like substance that helps several enzymes in the complicated process of converting food into energy. It is also an antioxidant that mops up harmful free radicals created during metabolism. There are numerous naturally occurring forms of Co-Q10, each with a slightly different molecular arrangement. However, coenzyme Q10 is the predominant form in humans and is the one renowned for therapeutic effects.

Where it comes from
Animal foods that contain mitochondria, including meat and fish, are whole-food sources of Co-Q10. Beef heart and liver are some of the richest sources; eggs offer negligible amounts. The human body synthesizes most Co-Q10 in a complex process that converts the amino acid tyrosine into Co-Q10, with the help of eight vitamins and several trace minerals. Yeast and soy oil are supplemental sources of Co-Q10.

Why it?s used
People with many types of heart problems, including high blood pressure, congestive heart failure, cardiomyopathy (heart disease that weakens the heart muscle), heart arrhythmia, angina, and those undergoing heart surgery, use Co-Q10 to improve their health. Co-Q10 also has shown potential in treating type 2 diabetes, migraines, Parkinson?s disease, gingivitis, and low sperm count, and as an adjuvant therapy for breast cancer. It may boost vitality in generally healthy people, especially those older than 40, when the body?s natural production of Co-Q10 starts to slow down (Ceska A Slovenska Farmacie, 2000, vol. 49, no. 3).

How it works
Co-Q10 can be thought of as the spark that starts the cellular machinery to produce energy. Because all cells need a constant supply of energy, levels of Co-Q10 can affect health in diverse ways. The heart muscle, in particular, consumes an extraordinary amount of energy and is thus very sensitive to Co-Q10 depletion.

Scientific support
A 30-year review study from the University of Southern California lauded the potential of Co-Q10 for the prevention and treatment of heart disease (Journal of Cardiovascular Nursing, 2002, vol. 16, no. 4). Consistently positive effects have been documented in patients with congestive heart failure, cardiomyopathy, heart arrhythmia, and angina.

Chronic migraine sufferers experience a reduction in migraine frequency while taking Co-Q10. The case is also fairly strong for other health benefits of Co-Q10. People with type 2 diabetes, for example, are better able to control their blood sugar levels while taking Co-Q10 (European Journal of Clinical Nutrition, 2002, vol. 56, no. 11). Chronic migraine sufferers experience a dramatic reduction in migraine frequency while taking Co-Q10 (Cephalalgia, 2002, vol. 22, no. 2). Many athletes have tried Co-Q10 hoping to improve endurance, but the research does not strongly support that outcome.

Co-Q10 can also be applied directly to the skin, where it protects against the aging effects of free radicals. Research with cosmetic creams containing Co-Q10 confirms that it can prevent visual signs of aging (Biofactors, 1999, vol. 9, no. 2).

Co-Q10 is sold in tablet, softgel, liquid, or capsule form and as a skin cream.

For basic adult health maintenance, 30 mg per day of Co-Q10 is the recommended dose. For treatment of specific health problems, the amount can vary. For example, researchers give people with heart problems, diabetes, or migraines 90 to 150 mg daily; breast cancer subjects use even higher amounts (390 mg per day). Because it is a fat-soluble nutrient, it?s best to take Co-Q10 with a meal that contains a little fat to optimize absorption.

A month?s supply of Co-Q10 costs as little as $10, at the basic daily dose of 30 mg. Higher doses of Co-Q10 will cost proportionately more.

Side effects
Co-Q10 is exceedingly safe in a wide variety of doses. But let the buyer beware: A recent evaluation of 32 Co-Q10 products found that not all contained the amount of Co-Q10 stated on the label. One product had no detectable Co-Q10; another exceeded the claimed amount by 75 percent. Protect yourself by buying Co-Q10 supplements that have been independently tested.

A few medical interactions with Co-Q10 should be noted: A popular family of cholesterol-lowering drugs known as HMG-CoA reductase inhibitors (which include lovastatin, pravastatin, and simvastatin) block the biosynthesis of Co-Q10. This results in lower levels of Co-Q10 in people taking these drugs. Supplementation with Co-Q10 (100 mg daily) can counteract this side effect. It?s also possible that Co-Q10 could slightly decrease the effectiveness of the blood thinner warfarin (Coumadin). As always, consult with your health care practitioner before taking any supplements.

Oregon-based writer Victoria Dolby Toews, MPH, is the author of User?s Guide to Glucosamine and Chondroitin (Basic Health Publications, 2002).