Coenzyme Q10

CoQ10: how it helps heart disease sufferers

The Irish Times
Health Supplement, p. 13
29 July 2008

DOES IT WORK? CoQ10 and heart disease

Coenzyme Q10, also called CoQ10 or ubiquinone, is an antioxidant found in small amounts in many foods, especially meat and seafood. It is chemically similar to the fat-soluble vitamins E and K, though it is not classified as a vitamin. Vitamins must be ingested in the diet because the body does not make sufficient. However, the human body normally produces enough CoQ10 for its own needs. CoQ10 plays an important role in the production of energy by the body’s cells and in preventing damage to cells via oxidation. It is found throughout the body, but in especially large concentrations in the heart, liver, kidney and pancreas.

A very small number of people produce insufficient CoQ10 and suffer from extreme fatigue and muscle weakness. CoQ10 has been approved in Japan for many years as a treatment for heart failure after if was noted that people with heart disease have reduced levels of CoQ10. The body normally produces less CoQ10 as we age and this led to claims in the 1990s that CoQ10 was the ‘fountain of youth’ and a miracle treatment for many diseases. Recent research has shown that CoQ10 might be useful for some people with heart disease, but its not going to cure everything.

Evidence from studies

The research on CoQ10 gives a confusing array of contradictory results. Part of the problem is that heart failure can develop for a number of different reasons. One treatment is therefore unlikely to help everyone. However, a number of patterns are visible in the results of the studies. One is that when CoQ10 is used as the only treatment for heart failure, the results are much less encouragements. Another pattern is that when CoQ10 is used along with conventional drugs for heart disease (like beta-blockers, ACE inhibitors or aspirin), the results are much more encouraging. Most of these studies found that CoQ10 along with prescription medications led to a better quality of life and improvements in objective measures of heart failure. Similarly, taking CoQ10 along with medications for high blood pressure led to larger reductions in blood pressure than occurred with the drugs alone.

Conventional treatment for high cholesterol levels often includes statin drugs. These drugs hinder the body’s production of cholesterol, but at the same time they interfere with the production of CoQ10. Researchers are examining whether CoQ10 supplements given with statins might reduce some of the side effects some people experience with these drugs. However, the results of these studies are preliminary at this point.

Problematic aspects

CoQ10 does not usually lead to adverse effects. Less than one percent of people get gastrointestinal problems like nausea, heartburn or diarrhoea. However, given that the supplements appear to be most beneficial along with conventional heart medications, anyone taking such medications should talk to the doctor before taking CoQ10. If benefits arise, it may require adjustments to the dose of any prescription medications.


The early hype about CoQ10 as a fountain of youth has been shown to be just that: hype. As a single treatment, only those with a rare deficiency in CoQ10 production are likely to have clear benefits.

CoQ10 is a powerful antioxidant and has an important general role in the body. Heart disease is associated with damage from oxidation. An antioxidant like CoQ10 would therefore be expected to provide some benefit to heart disease patients. However, an antioxidant will not correct any underlying heart disease, and hence the importance of taking conventional treatments along with CoQ10 supplements. Studies only show that CoQ10 is beneficial for heart failure when taken along with conventional medications. Taken on its own, there is very little evidence it helps with heart failure, or any of the other conditions for which it is sometimes recommended.

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