Coenzyme Q10 is an endogenously synthesised molecule found in the inner mitochondrial membrane of virtually every cell in the body. It functions as an electron carrier in the mitochondrial respiratory chain, transferring electrons between the protein complexes that generate ATP, and as a potent lipid-soluble antioxidant protecting cell membranes from oxidative damage. CoQ10 concentrations are highest in tissues with the greatest energy demands: the heart, liver, skeletal muscle, and kidneys. Endogenous synthesis declines with age and is substantially reduced by statin drugs, through their inhibition of the mevalonate pathway that produces both cholesterol and CoQ10.
Statins and CoQ10 Depletion
HMG-CoA reductase inhibitors, statins, block an early step in the mevalonate pathway, reducing not only cholesterol synthesis but also CoQ10 synthesis. Serum CoQ10 levels fall by 40 to 50 percent in statin-treated patients. A subset of statin-treated patients, estimated at 5 to 10 percent, develops statin-associated muscle symptoms including myalgia, weakness, and cramps. Whether CoQ10 depletion is the primary mechanism of statin myopathy and whether supplementation reliably prevents it has been debated, with mixed trial results, but clinical use is widespread and several trials show benefit in patients with documented statin myopathy.
Heart Failure Evidence
The Q-SYMBIO trial, a randomised double-blind placebo-controlled trial of CoQ10 supplementation in 420 patients with severe heart failure, found that CoQ10 at 300mg per day for two years significantly reduced cardiovascular mortality by 43 percent, improved heart failure symptoms, and reduced major adverse cardiovascular events. This is the strongest evidence for CoQ10 supplementation in any population and has led to interest in its use in cardiac rehabilitation and preventative cardiology.
Ubiquinol vs Ubiquinone
CoQ10 exists in two forms: ubiquinone, the oxidised supplemental form, and ubiquinol, the reduced, active antioxidant form. Ubiquinol is the form predominant in the body and may have superior bioavailability, particularly in older adults and those with compromised absorption. A pharmacokinetic study found that ubiquinol produced significantly higher plasma CoQ10 levels than equivalent doses of ubiquinone. For adults over 50 or those with significant health conditions, ubiquinol is the preferable supplemental form.
- If you take a statin and have muscle symptoms, discuss CoQ10 supplementation of 100 to 200mg per day with your prescriber
- For cardiovascular applications: 200 to 300mg of ubiquinol daily, taken with a fat-containing meal
- For migraine prevention: 300mg per day has evidence from randomised trials for reducing migraine frequency
- Ubiquinol is preferable to ubiquinone for adults over 50 due to better absorption
- CoQ10 supplements are highly sensitive to light and heat: store in a cool, dark location
Sources
- Mortensen, S.A., et al. (2014). The effect of coenzyme Q10 on morbidity and mortality in chronic heart failure: results from Q-SYMBIO. JACC: Heart Failure, 2(6), 641-649.
- Marcoff, L., & Thompson, P.D. (2007). The role of coenzyme Q10 in statin-associated myopathy. Journal of the American College of Cardiology, 49(23), 2231-2237.