Coenzyme Q10

Also indexed as: CoQ10, Ubiquinone

What does it do? Coenzyme Q10 (CoQ10) is a powerful antioxidant that protects the body from free radicals1 and helps preserve vitamin E, the major antioxidant of cell membranes and blood cholesterol.2 CoQ10 is also called ubiquinone, a name that signifies its ubiquitous (widespread) distribution in the human body. CoQ10 is used by the body to transform food into the energy on which the body runs, ATP.

CoQ10 supplementation has been investigated as a way to improve physical endurance because of its effect on energy production. However, most research shows that CoQ10 does not improve athletic performance.3 In other research, investigators reported no differences in CoQ10 in muscles or blood from patients with fibromyalgia compared to healthy people.4

Synthesis of sperm requires considerable energy. Due to its role in energy production, CoQ10 has been studied in infertile men. Preliminary research reports that supplementation of CoQ7, a related molecule, increased sperm counts in a group of infertile men.5

Healing of periodontal tissue (the gums of the mouth) may require increased energy production; therefore, researchers have explored the effects of CoQ10 supplementation in people with periodontal disease, which has been linked to CoQ10 deficiency. Double-blind research shows that people with gum disease given CoQ10 achieve better results than those given a placebo.6

The role of CoQ10 in energy formation also relates to how the body uses carbohydrates. Preliminary research suggests that a close relative of this nutrient lowered blood sugar levels in a group of people with diabetes.7 People with type 2 diabetes have been found to have significantly lower blood levels of CoQ10 compared with healthy people.8

Virtually every cell of the human body contains CoQ10. The mitochondria, the area of cells where energy is produced, contain the most CoQ10. The heart and liver contain the greatest amount of CoQ10. It has helped some people with congestive heart failure (CHF).9 —an effect reported in an analysis of eight controlled trials10 and found in some,11 though not all, double-blind studies.12 13 14 The beneficial effects of CoQ10 may not be seen until after several months of treatment. Discontinuation of CoQ10 supplementation in people with CHF has resulted in severe relapses and should only be attempted under the supervision of a doctor.15

Similar improvements have been reported in people with cardiomyopathies—a group of diseases affecting heart muscle. Research (including double-blind studies) in this area has been consistently positive.16

Also, due to its effect on heart muscle, researchers have studied CoQ10 in people with heart arrhythmias. Preliminary research in this area reported improvement after approximately one month in people with premature ventricular beats (a form of arrhythmia) who also suffer from diabetes.17

Angina patients taking 150 mg per day of CoQ10 report a greater ability to exercise without experiencing chest pain.18 This has been confirmed in independent investigations.19

CoQ10 appears to increase the heart’s tolerance to a lack of oxygen. Perhaps as a result, preliminary research has shown that problems resulting from heart surgery occurred less frequently in people given CoQ10 compared with the control group.20

Muscle mitochondria lack adequate CoQ10 in people with muscular dystrophy, a problem that could affect muscle function. In a double-blind three-month trial, four of eight people with muscular dystrophy had improvements in heart function and sense of well-being when supplementing CoQ10.21

Mitochondrial function also appears to be impaired in people with Alzheimer’s disease. Due to CoQ10’s effects on mitochondrial functioning, one group of researchers has given CoQ10 (along with iron and vitamin B6) to several people with Alzheimer’s disease and reported the progression of the disease appeared to have been prevented for one and a half, to two years.22

CoQ10 also modulates immunity.23 Perhaps as a result, a few cases have been reported in which women with metastatic breast cancer (cancer that had spread to other tissues) had a regression of their cancer after treatment with a very large amount of CoQ10 (390 mg per day).24

CoQ10 appears to modulate blood pressure by reducing resistance to blood flow.25 Several trials have reported that supplementation with CoQ10 significantly reduced blood pressure in people with hypertension, usually after ten weeks to four or more months of treatment.26

In a double-blind study of 21 patients with chronic renal (kidney) failure, 15 of whom were on dialysis, supplementation with 60 mg of CoQ10 three times per day for four weeks improved certain measures of kidney function (BUN, serum creatinine, and creatinine clearance), compared with placebo, and eliminated the need for dialysis in some patients.27 Because chronic renal failure is a serious and complicated disease, individuals with this condition should take CoQ10 only under strict medical supervision.

Where is it found? CoQ10 is found primarily in fish and meat, but the amounts in food are far less than what can be obtained from supplements.

Coenzyme Q10 has been used in connection with the following conditions (refer to the individual health concern for complete information):

Rating Health Concerns
3Stars Angina
High blood pressure
2Stars Cardiomyopathy
Cerebellar ataxia (familial)
Congestive heart failure
Diabetes
Gingivitis (periodontal disease)
Halitosis (if gum disease)
Heart attack
Renal (kidney) failure
1Star Alzheimer’s disease
Athletic performance
Breast cancer
Chronic obstructive pulmonary disease (COPD)
HIV support
Infertility (male)
Insulin resistance syndrome (Syndrome X)
Lung cancer
Muscular dystrophy
Prostate cancer
3Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star An herb is primarily supported by traditional use, or the herb or supplement has little scientific support and/or minimal health benefit.

Who is likely to be deficient? Deficiency is poorly understood, but it may be caused by synthesis problems in the body rather than an insufficiency in the diet. Low blood levels have been reported in people with heart failure, cardiomyopathy, gingivitis (inflammation of the gums), morbid obesity, hypertension, muscular dystrophy, diabetes, AIDS, and in some people on kidney dialysis. People with phenylketonuria (PKU) may be deficient in CoQ10 because of dietary restrictions.28 CoQ10 levels are also generally lower in older people. The test used to assess CoQ10 status is not routinely available from medical laboratories.

Which form of coenzyme Q10 is best? Some,29 but not all,30 research suggests that a fat-soluble form of CoQ10 is absorbed better than CoQ10 in granular (powder) form.31

How much is usually taken? Adult levels of supplementation are usually 30–90 mg per day, although people with specific health conditions may supplement with higher levels (with the involvement of a physician). Most of the research on heart conditions has used 90–150 mg of CoQ10 per day. People with cancer who consider taking much higher amounts should discuss this issue with a doctor before supplementing. There are several anecdotal reports of large amounts of CoQ10 resulting in improvements in certain types of cancer. However, controlled trials are needed to confirm these preliminary observations. Most doctors recommend that CoQ10 be taken with meals to improve absorption.

Are there any side effects or interactions? Congestive heart failure patients who are taking CoQ10 should not discontinue taking CoQ10 supplements unless under the supervision of a doctor.

An isolated test tube study reported that the anticancer effect of a certain cholesterol-lowering drug was blocked by addition of CoQ10.32 So far, experts in the field have put little stock in this report because its results have not yet been confirmed in animal, human, or even other test tube studies. The drug used in the test tube is not used to treat cancer, and preliminary information regarding the use of high amounts of CoQ10 in humans suggests the possibility of anticancer activity.33 34 35

Are there any drug interactions? Certain medications may interact with coenzyme Q10. Refer to the drug interactions safety check for a list of those medications.

References:

1. Weber C, Jakobsen TS, Mortensen SA, et al. Antioxidative effect of dietary coenzyme Q10 in human blood plasma. Int J Vitam Nutr Res 1994;64:311–5.

2. Thomas SR, Neuzil J, Stocker R. Inhibition of LDL oxidation by ubiquinol-10. A protective mechanism for coenzyme Q in atherogenesis? Mol Aspects Med 1997;18:S85–103.

3. Kelly GS. Sport nutrition: a review of selected nutritional supplements for endurance athletes. Altern Med Rev 1997;2:282–95.

4. Thorsteindottir B, Rafnsdottir S, Geirsson AJ, et al. No difference in ubiquinone concentration of muscles and blood in fibromyalgia patients and healthy controls. Clin Exp Rheumatol 1998;16:513–4.

5. Tanimura J. Studies on arginine in human semen. Part III. The influences of several drugs on male infertility. Bull Osaka Med School 1967;12:90–100.

6. Gaby AR. Coenzyme Q10. In A Textbook of Natural Medicine, by Pizzorno JE, Murray MT. Seattle: Bastyr University Press, 1998, V:CoQ10–1–8. [review].

7. Shigeta Y, Izumi K, Abe H. Effect of coenzyme Q7 treatment on blood sugar and ketone bodies of diabetics. J Vitaminol 1966;12:293–8.

8. Miyake Y, Shouzu A, Nishikawa M, et al. Effect of treatment of 3-hydroxy-3-methylglutaryl coenzyme I reductase inhibitors on serum coenzyme Q10 in diabetic patients. Arzneimittelforschung 1999;49:324–9.

9. Mortensen SA, Vadhanavikit S, Baandrup U, Folkers K. Long-term coenzyme Q10 therapy: a major advance in the management of resistant myocardial failure. Drug Exptl Clin Res 1985;11:581–93.

10. Soja AM, Mortensen SA. Treatment of chronic cardiac insufficiency with coenzyme Q10, results of meta-analysis in controlled clinical trials. Ugeskr Laeger 1997;159:7302–8.

11. Morisco C, Trimarco B, Condorelli M. Effect of coenzyme Q10 in patients with congestive heart failure: a long-term multicenter randomized study. Clin Investig 1993;71:S134–6.

12. Permanetter B, Rossy W, Klein G, et al. Ubiquinone (coenzyme Q10) in the long-term treatment of idiopathic dilated cardiomyopathy. Eur Heart J 1992;13:1528–33.

13. Watson PS, Scalia GM, Galbraith A, et al. Lack of effect of coenzyme Q on left ventricular function in patients with congestive heart failure. J Am Coll Cardiol 1999;33:1549–52.

14. Khatta M, Alexander BS, Krichten CM, et al. The effect of coenzyme Q10 in patients with congestive heart failure. Ann Intern Med 2000;132:636–40.

15. Mortensen SA, Vadhanavikit S, Baandrup U, Folkers K. Long-term coenzyme Q10 therapy: a major advance in the management of resistant myocardial failure. Drug Exptl Clin Res 1985;11:581–93.

16. Gaby AR. The role of coenzyme Q10 in clinical medicine: part II. Cardiovascular disease, hypertension, diabetes mellitus and infertility. Altern Med Rev 1996;1:168–75 [review].

17. Fujioka T, Sakamoto Y, Mimura G. Clinical study of cardiac arrhythmias using a 24-hour continuous electrocardiographic recorder (5th report)—antiarrhythmic action of coenzyme Q10 in diabetics. Tohoku J Exp Med 1983;141(suppl):453–63.

18. Kamikawa T, Kobayashi A, Yamashita T, et al. Effects of coenzyme Q10 on exercise tolerance in chronic stable angina pectoris. Am J Cardiol 1985;56:247.

19. Mortensen SA. Perspectives on therapy of cardiovascular diseases with coenzyme Q10 (ubiquinone). Clin Invesigt 1993;71:S116–23 [review].

20. Tanaka J, Tominaga R, Yoshitoshi M, et al. Coenzyme Q10: the prophylactic effect on low cardiac output following cardiac valve replacement. Ann Thorac Surg 1982;33:145–51.

21. Folkers K, Wolaniuk J, Simonsen R, et al. Biochemical rationale and the cardiac response of patients with muscle disease to therapy with coenzyme Q10. Proc Natl Acad Sci 1985;82:4513–6.

22. Imagawa M, Naruse S, Tsuji S, et al. Coenzyme Q10, iron, and vitamin B6 in genetically-confirmed Alzheimer’s disease. Lancet 1992;340:671 [letter].

23. Folkers K, Shizukuishi S, Takemura K, et al. Increase in levels of IgG in serum of patients treated with coenzyme Q10. Res Commun Pathol Pharmacol 1982;38:335–8.

24. Lockwood K, Moesgaard S, Yamamoto T, Folkers K. Progress on therapy of breast cancer with vitamin Q10 and the regression of metastases. Biochem Biophys Res Commun 1995;212:172–7.

25. Digiesi V, Cantini F, Bisi G, et al. Mechanism of action of coenzyme Q10 in essential hypertension. Curr Ther Res 1992;51:668–72.

26. Gaby AR. The role of coenzyme Q10 in clinical medicine: part II. Cardiovascular disease, hypertension, diabetes mellitus and infertility. Altern Med Rev 1996;1:168–75 [review].

27. Singh RB, Khanna HK, Niaz MA. Randomized, double-blind placebo-controlled trial of coenzyme Q10 in chronic renal failure: discovery of a new role. J Nutr Environ Med 2000;10:281–8.

28. Artuch R, Vilaseca MA, Moreno J, et al. Decreased serum ubiquinone-10 concentrations in phenylketonuria. Am J Clin Nutr 1999;70:892–5.

29. Weiss M, Mortensen SA, Rassig MR, et al. Bioavailability of four oral coenzyme Q10 formulations in healthy volunteers. Molec Aspects Med 1994;15:273–80.

30. Kaikkonen J, Nyyssonen K, Porkkala-Sarataho E, et al. Effect of oral coenzyme Q10 on the oxidation resistance of human VLDL + LDL fraction: absorption and antioxidative properties of oil and granule-based preparations. Free Radic Biol Med 1997;22:1195–202.

31. Chopra RK, Goldman R, Sinatra ST, Bhagavan HN. Relative bioavailability of coenzyme Q10 formulations in human subjects. Int J Vitam Nutr Res 1998;68:109–13.

32. Larsson O. Effects of isoprenoids on growth of normal human mammary epithelial cells and breast cancer cells in vitro. Anticancer Res 1994;114:123–8.

33. Lockwood K, Moesgaard S, Folkers K. Partial and complete regression of breast cancer in patients in relation to dosage of coenzyme Q10. Biochem Biophys Res Commun 1994;199:1504–8.

34. Lockwood K, Moesgaard S, Yamamoto T, Folkers K. Progress on therapy of breast cancer with vitamin Q10 and the regression of metastases. Biochem Biophys Res Commun 1995;212:172–7.

35. Judy WV. Nutritional intervention in cancer prevention and treatment. American College for Advancement in Medicine Spring Conference, Ft. Lauderdale, FL. May 3, 1998.