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CoQ10

(October 2001)

Currently, one of the most popular nutritional supplements is co-enzyme Q10 (CoQ10). CoQ10 is involved in energy production. It is an antioxidant. Supposedly, 50 million people around the world take it daily, 12 million of them in Japan. A perusal of the literature and the promotional statements on the internet suggest it is an astounding substance that can be recommended for treatment or prevention of:

It is also said to increase energy, improve the performance of athletes, counteract aging, prolong life, and prevent drug toxicity. It has been said that everyone who has a serious disease or might eventually get one should be taking CoQ10. It is often called a miracle drug, a fountain of youth.

It all sounds too good to be true - and so it is. What do we actually know?

CoQ10 is interesting, but it has not been shown to prevent any disease. In two animal studies, it did prolong life of rodents, but there is no evidence in man that it reverses or stops the aging process or that it can prolong life.

What about that extraordinary list of diseases it allegedly can be used to treat? There is very little solid evidence. One of the best studies on angina (heart pain) involved only twelve patients. There were some benefits, but no significant decrease in the frequency of anginal attacks or the need to use drugs, such as nitroglycerin. Another use is in patients with heart muscle degeneration (an infrequent disease called cardiomyopathy) that is ordinarily fatal. Prolonged treatment with CoQ10 in one study did appear to prolong life; unfortunately, there was no comparison group. There are also studies suggesting that CoQ10 is effective in congestive heart failure due to arteriosclerosis of the blood vessels of the heart, so CoQ10 looks interesting in degenerative heart muscle disease and, possibly, in congestive heart failure. It is important to note that there are also studies of cardiomyopathy and congestive failure in which CoQ10 was not effective. Recent studies also suggest that CoQ10 may be quite useful in the treatment of two rare neurological diseases, characterized by incoordination and severe muscle dysfunction or paralysis. However, at present, there is no disease in which there are enough studies to make a definitive statement.

There are a lot of unanswered questions. We do not know how much is needed in the diet to prevent CoQ10 deficiency. We do not know whether the dosage in supplements is just preventing deficiencies, or whether CoQ10 in the recommended dose has other actions than preventing or reversing deficiencies. The usual dietary CoQ10 intake is about 5 milligrams, whereas the dosage used in supplements ranges from 10 to 300 milligrams with most recommendations in the 50 to 150 milligrams range. We just do not know optimal dosage.
Although CoQ10 is interesting, at this point, it gets a

for any health promotion claim for apparently healthy people.

For angina, heart muscle disease, and congestive heart failure, it rates

It appears that, in dosages of 150 milligrams a day or less, CoQ10 is quite safe, but we do not have adequate information on possible long-term adverse effects.

We just do not know enough about possible adverse effects of dosages over 150 milligrams per day.

CoQ10 is not inexpensive, costing in the range of 50 to 75 cents a capsule. Entrepreneurs are making a lot of money with their hype. They say it is absolutely safe, but, at the same time, they do not recommend it for pregnant or lactating women. They tell us what a miracle drug it is for an incredible array of diseases, then, at the bottom of advertisements, they indicate it is not intended to treat any disease. That is so they can continue to sell it as a nutritional supplement, and not have to do the studies required of a drug. That is hypocritical! They are making clear drug claims through their advertising and background materials. CoQ10 could turn out to be useful, but we need good, controlled studies before coming to any judgment.

For those who want to be sure to have sufficient CoQ10 in their diets, the major dietary sources are meats (beef, pork, lamb - especially beef and pork hearts) and poultry. Other pretty good sources are fish (salmon, herring, trout), nuts, eggs, dairy products, broccoli, brussel sprouts, and cauliflower.