Coenzyme Q-10 (CoQ10) Pills Do Not Increase Endurance
Report #7248
Coenzyme Q-10 (ubiquinone or CoQ10) is a fat-soluble vitamin-like substance made by your body. It is found in all human tissues, with particularly high levels in the mitochondria of muscles. It forms many different enzymes that help your body to use oxygen to power your muscles during exercise.
Athletes who take coenzyme Q-10 pills have higher blood levels of that enzyme, but do not have greater endurance or increase in their ability to take in and use oxygen (1,2). Of six placebo-controlled studies, one showed that cross country skiers raced faster after taking coenzyme Q-10 pills, but the other five showed no improvement in muscle energy metabolism, muscle fatigue, endurance, or maximal ability to take in and use oxygen (VO2 max) (1,2).
For coenzyme
Q10 to increase endurance, it must get into the mitochondria. Studies
show that coenzyme Q10 from pills gets into the bloodstream, but it cannot be recovered in
the cells (3).
At least nine placebo-controlled studies show that coenzyme Q-10 helps to treat heart failure. CoQ10 is known to be highly concentrated in heart muscle cells and people in heart failure have very low blood and tissue levels of coenyme Q10 (3) .
Coenzyme Q-10 is an effective antioxidant. Reactions in your body produce chemicals called oxidants that damage cells and shorten life. To protect your cells from oxidant damage, your body produces antioxidants such as superoxide dismutase and coenzyme Q10. Since tissue levels of coenzyme Q10 drop with aging, it was tempting to think that reduced levels of this coenzyme cause aging. However, research shows that lowered levels are the result of aging rather than the cause. Coenzyme Q10 is found in the mitochondria, the energy sources of cells. With aging, the number of mitochondria and size of cells become smaller, so everything in the mitochondria is reduced.
Coenzyme Q10 supplements have been shown to be ineffective in treating heart attacks (5) and diseases affecting the mitochondria (6). Years ago, a researcher at the University of Texas showed that people who have arteriosclerotic heart disease have lower blood levels of coenzyme Q10 than people who have normal hearts. People with damaged hearts have less functioning heart muscle, so they should have lower levels of coenzyme Q10.
Although low levels of coenzyme Q-10 have been reported in muscle damage caused by taking statin drugs to lower cholesterol, most studies show that coenzyme Q-10 pills do not prevent or treat that problem (7).
By Gabe Mirkin, M.D., for CBS Radio News
1) Weston, S.B.; Zhou, S.; Weatherby, R.P.; Robson, S.J. Does exogenous coenzyme Q(10)
affect aerobic capacity in endurance athletes? International Journal of Sport Nutrition.
SEP 1997;7(3):197-206. 2) Porter DA et al. The effect of oral coenzyme Q10 on the exercise tolerance of
middle-aged, untrained men. International Journal of Sports Medicine
1995(Oct);16(7):421-427. 3) Zhang Y et al. Uptake of dietary coenzyme Q supplement is limited in rats. J. Nutr.
1995(Mar);125(3):446-453. 4) Nutrition News POB 55279 Riverside, Cal 92517. 1987 volume X, number 8. 5) Y Birnbaum, SL Hale, RA Kloner. The effect of coenzyme Q(10) on infarct size in a
rabbit model of ischemia/reperfusion. Cardiovascular Research 32: 5 (NOV 1996):861-868.
Conclusions: Coenzyme Q(10), administered acutely either during or 60 min before
myocardial ischemia, does not attenuate infarct size in the rabbit. 6) Mathews PM et al. Coenzyme Q10 with multiple vitamins is generally ineffective in
treatment of mitochondrial disease. Neurology. 1993(May);43(5):884-890. 7) The Role of Coenzyme Q10 in Statin-Associated Myopathy A Systematic Review Leo Marcoff, MD* and Paul D. Thompson, MD J Am Coll Cardiol, 2007; 49:2231-2237.
Updated 8/5/09