Coenzyme Q10 (CoQ10) is a fat-soluble, vitamin-like substance in every human cell. It's involved in key biochemical reactions that produce energy in cells. It also acts as an antioxidant (an"tih-OK'sih-dant). CoQ10 is naturally present in a variety of foods. Organ meats such as heart, liver and kidney as well as in beef, soybean oil, sardines, mackerel and peanuts are particularly high in CoQ10.
Less CoQ10 has been observed in some people with cardiac failure due to different causes. Much of the research has been done in patients with congestive heart failure. Some of these studies have shown positive results and others haven't. With one exception, these studies have been done with small numbers of patients for relatively short periods. It's important to note that CoQ10 was given in addition to traditional drug treatments. This makes it hard to know which treatment was the effective one.
The ACC/AHA publication "Guidelines for the Evaluation and Management of Chronic Heart Failure in the Adult" reviewed the available data. It concluded that until more data are available, nutritional supplements such as coenzyme Q10 cannot be recommended to treat heart failure.
The ACC/AHA publication "2002 Guideline Update for the Management of Patients with Chronic Stable Angina" also lists coenzyme Q10 as a treatment that's not useful or effective for patients with angina.
The safety and effectiveness of CoQ10 need to be further evaluated. This requires conducting well-designed clinical trials involving large numbers of patients over a long time. Until that happens, the American Heart Association cannot recommend taking coenzyme Q10 regularly.
