Coenzyme Q10 is manufactured by the body, and plays a valuable role in the mitochondria; the working metabolism within individual cells. CoQ10 also functions as an antioxidant there, protecting the cells' DNA from free radicals. It is abundant in hard working muscles, especially the heart. Levels of CoQ10 tend to decline with age, and are lower in congestive heart failure and other diseases. There is speculation that replenishing the body's CoQ10 might help treat those diseases and slow the aging process, but evidence of such is still questionable at this time.
CoQ10 is often recommended for heart failure or cardiomyopathy patients since the majority show a deficiency. In these instances, it can be a valuable tool. Whether it can prevent heart disease has yet to be studied. The typical dose is 200mg/day, and toxicity levels have not yet been established.
Some statin users claim to benefit from the supplement, though there is no confirmed evidence that the CoQ10 alone provided the relief from muscle aches. This is one of the problems some people experience with statins. Researchers believe that pain occurs when the mitochondria become impaired because their natural CoQ10 has been depleted by the statins. Here's how it works: The same enzyme makes both cholesterol and CoQ10, so when the statins block cholesterol production, they are also blocking the production of the body's natural CoQ10. Since there are no known risks to taking the supplement, one can only give it a try. As always, check with your doctor before taking any supplements.
Can healthy people benefit from CoQ10 as a preventative? Probably not. In studies with healthy mice, it didn't do much of anything to prevent disease or delay aging.