Many claims are made for Coenzyme Q10 (CoQ10) is also known as ubiquinone because it belongs to a class of compounds called quinones, and because it’s ubiquitous in living organisms, especially in the heart, liver and kidneys.
This vitamin-like compound, discovered in 1957, plays a crucial role in producing energy in cells. It also acts as a powerful antioxidant, meaning that it helps neutralize cell-damaging free radicals. Manufactured by all cells in the body, CoQ10 is also found in small amounts in some foods, notably meat and fish.
Sold as a dietary supplement, CoQ10 is purported to help treat, or possibly prevent, heart disease, hypertension, Parkinson’s disease, certain cancers, migraines, HIV/AIDS, infertility, gum disease, allergies and so on. It’s also said to boost immunity, enhance athletic performance, aid memory and slow aging.
Like many substances in the body, CoQ10 levels decline with age and are lower in people with certain medical conditions, such as Parkinson’s, some cardiac disorders and asthma. But that doesn’t mean that CoQ10 “deficiency” causes disease or that supplements will treat disease or reverse the effects of aging.
Some cholesterol-lowering statin drugs, as well as certain beta-blockers and antidepressants, can reduce blood levels of CoQ10, but there’s no evidence that this leads to any health problems.
Putting CoQ10 to the test
According to the Natural Standard, which evaluates complementary and alternative therapies, there is “unclear scientific evidence” for most uses of CoQ10, and “fair scientific evidence” against its use for diabetes and Huntington’s disease. Much of the encouraging research has been in the lab, while human studies have tended to yield inconsistent results. Here are some uses that look more promising:
Hypertension. An analysis of 12 studies of people with hypertension, in the Journal of Human Hypertension in 2007, found that CoQ10 lowered systolic blood pressure (the top number in a blood pressure reading) 11 to 17 points, and diastolic (the bottom number) 8 to 10 points. This may be due to CoQ10’s ability to dilate blood vessels. The Natural Standard gives CoQ10 a “B” for hypertension, citing “good” evidence for this use but also the need for more studies.
Heart conditions. People with cardiac disease often have low levels of CoQ10, and cells of the heart are sensitive to reductions in CoQ10. According to a 2010 review in Nutrition, heart failure patients with low CoQ10 have higher death rates. CoQ10 has shown a range of heart benefits, including a reduction in arrhythmias after bypass surgery and improvements in cardiac function indicators in people with heart failure. CoQ10 may benefit the cardiovascular system through its antioxidant and anti-inflammatory effects and by improving blood vessel function.