Coenzyme Q10 is a fat-soluble, vitamin-like quinone that is available in more than 100 single- and combination-ingredient products; in 2008 it accounted for over $450 million in sales in North America.
Claims for CoQ10’s benefits include improvements in congestive heart failure, an anticancer effect secondary to immune-stimulating properties, slowed progression of Parkinson’s disease, lower insulin requirements in diabetes, and any number of processes that involve cellular energy metabolism or oxidative cellular damage. (The Merck Manual, 18th Edition. Coenzyme Q10. 2006. Pp2728-29)
The Dietary Supplement Health and Education Act (DSHEA) of 1994 prevents anyone in the US from making claims about Co10’s efficacy for the treatment or prevention of specific diseases. However, the FDA has granted some forms of CoQ10 orphan drug status for the treatment of certain conditions.
CoQ10’s supporters often claim that the supplement is given short shrift in America because pharmaceutical companies (and their political allies) benefit financially from blocking its widespread use. They believe that CoQ10 could address a myriad of ills if it was better-studied and if health care professionals were educated about its benefits and allowed to prescribe it freely.
CoQ10 for Parkinsons’s Disease
- One study in 80 patients showed that 1,200 mg daily of CoQ10 slowed functional decline by 44%. Another smaller trial demonstrated mild improvement in symptoms with 360 mg daily. (Shults C, et al. Effects of coenzyme Q10 in early Parkinson disease: evidence of slowing of the functional decline. Arch Neurol 2002;59:1541-50 and Muller T, et al. Coenzyme Q10 supplememtation provides mild symptomatic benefit in patients with Parkinson’s disease. Neurosci Lett 2003;341:201-4)
CoQ10 for Migraine Headaches
- One early, non-blinded trial demonstrated a reduction in frequency of migraine attacks among patients taking 150 mg CoQ10 daily. A more recent and better-designed study found similar benefit for patients taking 300 mg per day. (Sandor P, et al. Efficacy of coenzyme Q10 in migraine prophylaxis: a randomized controlled trial. Neurology 2005;64:713-15)
CoQ10 for Mitochondrial Encephalopathies
- Mitochondrial cytopathies are a group of disorders characterized by mutations in the genes of mitochondrial DNA. These mutations interfere with mitochondrial protein synthesis, aerobic metabolism, and energy production.
- In several small studies, CoQ10 reduced the symptoms of mitochondrial encephalopathies, such as the MELAS syndrome, Kearns-Sayre syndrome, and the MERRF syndrome.
- One specific preparation of CoQ10, UbiQGel, was granted orphan drug status by the US Food and Drug Administration following these trials.
CoQ10 for Huntington’s Disease
- Huntington’s disease, a progressive neurological disease caused by an autosomal dominant gene, has not been shown to respond to CoQ10 at doses less than 600 mg daily. Data for higher doses are not sufficient to recommend CoQ10 for this condition.
- Despite a lack of support for its use, CoQ10 has been granted orphan drug status by the FDA for treating Huntington’s disease.
CoQ10 for Congestive Heart Failure
- Although CoQ10’s role in cardiovascular disease has been widely studied, many early trials were weakened by small study groups and by technology that has become outdated.
- More recent trials at lower doses of CoQ10 (100 – 200 mg daily) found it to be no more effective than placebo in improving cardiac ejection fraction, peak oxygen consumption, exercise duration, or quality of life. These studies do not address the effects of higher doses of CoQ10, which are often recommended for treating cardiovascular conditions.
- Special consideration must be given to individuals with CHF who are taking statin drugs to lower their cholesterol levels. Statins block the enzyme that makes CoQ10; theoretically, this could further impair the already compromised heart muscle in persons with CHF.
- Since statins are vigorously marketed in the US, a great deal of controversy surrounds their putative contribution to CHF.
- Japanese physicians have been using CoQ10 to treat congestive heart failure since 1974. (Tran M, et al. Role of coenzyme Q10 in chronic heart failure, angina, and hypertension. Pharmacotherapy 2001;21:797-806)
CoQ10 for Hypertension
- A systematic review of eight trials showed a potential benefit for using CoQ10 (usually with prescription drugs) for decreasing high blood pressure.
- Several of these studies were limited by confounding variables or low statistical power.
- CoQ10 shows promise for benefit in other cardiovascular settings, including atherosclerosis, cardiopulmonary resuscitation, and cardiac surgery.
CoQ10 for Diabetes
- Although early studies of CoQ10’s effects on glycemic control in diabetes were disappointing, a more recent trial demonstrated modest improvement in long-term blood glucose control.
CoQ10 for Cancer
- CoQ10 is frequently recommended for the treatment and prevention of cancer, but the Agency for Healthcare Research and Quality has found no compelling evidence to assess its use in malignant diseases.
(Adapted from Bonakdar R, Guarneri E. Coenzyme Q10. Am Fam Phys 2005;72(6):1065-70)
There are no absolute contraindications to taking CoQ10, and adverse effects are rare. Mild stomach upset is reported in less than 1% of subjects in clinical trials. CoQ10 is a safe supplement whose range of benefits is largely unexplored.
