Another name for coenzyme Q10—ubiquinone—gives us an idea of just how important a compound it is, and how frequently it’s found in living organisms. It is “ubiquitous,” as it is found in almost all cell membranes and lipoproteins, where it inhibits the peroxidation of structural lipids. Its most well-known role, however, is in transferring electrons along the mitochondrial electron transport chain. The “10” part of CoQ10 refers to its biochemical structure, which consists of ten isoprene units attached to a benzoquinone head.
CoQ10 is a fat-soluble compound synthesized endogenously on a branch of the mevalonate pathway, which also produces cholesterol. Dietary sources highest in CoQ10 are animal proteins (beef, poultry and fish), with smaller amounts occurring in nuts and seeds, and even smaller amounts found in some vegetables and fruits. Among animal sources of CoQ10, the richest concentrations occur in hardworking tissue, such as heart, liver and kidney. Because it can be synthesized internally, it’s not technically an “essential” nutrient. However, as is the case with many vitamins and minerals, supplemental amounts of this nutrient may be beneficial forameliorating specific health conditions, preventing or limiting oxidative damage, and giving the body a leg up when it comes to performing certain tasks.
One area in which CoQ10 may offer a slight advantage is in physical exercise performance and recovery. This isn’t surprising, considering its aforementioned role in the mitochondrial electron transport chain—the mechanism by which the vast majority of skeletal muscle cells’ energy (ATP) is generated. Sufficient CoQ10, therefore, is instrumental in providing the body with the energy to perform physical exercise, but this nutrient’s role extends even further than that. As a powerful antioxidant, supplemental CoQ10 has been shown to reduce oxidative stress and inflammation induced by strenuous exercise. In highly trained male athletes, oral CoQ10supplementation was shown to decrease membrane hydroperoxides, 8-Hydroxy-2’-deoxyguanosine (8-OHdG, a marker for DNA damage due to oxidation), and the inflammatory marker, TNF-α. It also resulted in reduced creatinine excretion, suggestive of decreased muscle tissue damage.
A double-blind, randomized, placebo-controlled trial involving elite Japanese athletes engaging in long bouts of kendo (a martial art) showed that CoQ10 supplemented at 300mg/day was effective for lowering lipid peroxidation, serum myoglobin, and serum creatine kinase compared to placebo, suggesting that supplementation may reduce exercise-induced muscle damage.
These findings are logical, given CoQ10’s well-recognized antioxidant function. Regarding the role of CoQ10 in enhancing athletic performance, however, a systematic review of studies provided mixed results. Studies included trained as well as untrained subjects, across a variety of activities, including cycling, skiing, and general athletics. In the studies that did show a benefit from CoQ10, the positive changes were in maximum oxygen consumption, and exercise capacity. It may be that supplementation only benefited those with lower levels to begin with, and most of the studies involved small sample sizes, which may have weakened the findings.
There may still be a small role for CoQ10 in athletic performance, however. In a double-blind, crossover RCT employing 300mg/day of CoQ10, the test group reached a greater maximum velocity and reported reduced subjective fatigue, compared to placebo, after performing workload trials on a bicycle ergometer.
Rather than providing athletes—and weekend warriors, alike—with a performance edge during exercise, it seems the benefits of CoQ10 are more closely tied to its antioxidant and anti-inflammatory function. The CoQ10-mediated decrease in cellular damage incurred by exercise may reduce recovery time and better prepare athletes for their next training session.
Bottom line: CoQ10 isn’t going to turn a couch potato into an Olympic medalist, but by decreasing the cellular damage induced by exercise, and reducing feelings of fatigue, it might help people engage more frequently in physical activities they enjoy, which may contribute to overall improved health.