Coenzyme Q10

Also Known As
CoQ10, ubiquinone

Physiology and Clinical Effects
Coenzyme Q10 is a powerful antioxidant that protects the body from free radicals.¹ Coenzyme Q10 is also called ubiquinone, a name that signifies its ubiquitous (widespread) distribution in the human body. As a coenzyme, this nutrient aids metabolic reactions, such as the complex process of transforming food into ATP, the energy on which the body runs.

Coenzyme Q10 supplementation has been investigated as a way to improve physical endurance because of its effect on energy production. However, most research shows that coenzyme Q10 does not improve athletic performance.²

Synthesis of sperm requires considerable energy. Due to its role in energy production, coenzyme Q10 has been studied in infertile men. Preliminary research reports that supplementation of coenzyme Q7, a related molecule, increased sperm counts in a group of infertile men.³

Healing of periodontal tissue (the gums of the mouth) may require increased energy production; therefore, researchers have explored the effects of coenzyme Q10 supplementation in people with periodontal disease, which has been linked to coenzyme Q10 deficiency. Double-blind research shows that people with gum disease given coenzyme Q10 achieve better results than those given placebo.⁴

The role of coenzyme Q10 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 diabetics.⁵

Virtually every cell of the human body contains coenzyme Q10. The mitochondria, the area of cells where energy is produced, contain the most coenzyme Q10. The heart and liver, because they contain the most mitochondria per cell, have the greatest amount of coenzyme Q10. Coenzyme Q10 helps people with congestive heart failure⁶—an effect proven in double-blind research.⁷ Coenzyme Q10 may take several months to show beneficial results. People with congestive heart failure taking coenzyme Q10 should not stop taking it suddenly because sudden withdrawal may exacerbate the symptoms of congestive heart failure.⁸

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.⁹

Also, due to its effect on heart muscle, researchers have studied coenzyme Q10 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.¹⁰

Angina patients taking 150 mg per day of coenzyme Q10 report a greater ability to exercise without problems.¹¹ This has been confirmed in independent investigations.¹²

Coenzyme Q10 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 in people given coenzyme Q10 compared with the control group.¹³

Muscle mitochondria lack adequate coenzyme Q10 in people with muscular dystrophy, a problem that could affect muscle function. In a preliminary double-blind three-month trial, four of eight people with muscular dystrophy had improvements in heart function and sense of well-being when supplementing coenzyme Q10.¹⁴

Mitochondrial function also appears to be impaired in people with Alzheimer’s disease. Due to coenzyme Q10’s effects on mitochondrial functioning, one group of researchers has given coenzyme Q10 (along with iron and vitamin B6) to several people with Alzheimer’s disease and reported that the progression of the disease appeared to have been prevented for one and one-half to two years.¹⁵

Coenzyme Q10 also modulates immunity.¹⁶ Perhaps as a result, preliminary research suggests that women with a high risk of breast cancer recurrence show evidence of protection when given very high (390 mg per day) levels of coenzyme Q10 for up to five years.¹⁷

Coenzyme Q10 appears to modulate blood pressure by reducing resistance to blood flow.¹⁸ Several trials have reported that supplementation with coenzyme Q10 for at least several months significantly reduces blood pressure in people with hypertension.¹⁹

Food Sources
Coenzyme Q10 is primarily found in fish and meat.

Deficiency Risk and Symptoms
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, cardiomyopathies, gingivitis (inflammation of the gums), morbid obesity, hypertension, muscular dystrophy, AIDS, and in some people on kidney dialysis. Coenzyme Q10 levels are also generally lower in older individuals. The test used to assess coenzyme Q10 status is not routinely available from medical laboratories.

Recommended Dosage
Adult levels of supplementation are usually 30–90 mg per day, although individuals 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 coenzyme Q10 per day. People with cancer who consider taking much higher amounts should discuss this issue with a doctor before supplementing. Most doctors recommend that coenzyme Q10 be taken with meals to improve absorption.

Which Form Of Coenzyme Q10 Is Best?
Some,²⁰ but not all,²¹ research supports the idea that oil-based suspension of coenzyme Q10 absorbs better than forms that lack oil. Of the oil-based products, solubilized coenzyme Q10 absorbed the best according to one group of researchers.²²

Contraindications
Congestive heart failure patients who are taking coenzyme Q10 should not discontinue taking coenzyme Q10 supplements without first consulting a doctor.

An isolated test tube study reported that the anticancer effect of a certain cholesterol-lowering drug was blocked by addition of coenzyme Q10.²³ 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 coenzyme Q10 in humans suggests the possibility of anticancer activity.^{24 25 26}

References:

1. Weber C, Jakobsen TS, Mortensen SA, et al. Antioxidative effect of dietary coenzyme Q10 in human blood plasma. Internat J Vit Nutr Res 1994;64:311–5.
2. Kelly GS. Sport nutrition: a review of selected nutritional supplements for endurance athletes. Alt Med Rev 1997;2:282–95.
3. 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.
4. Gaby AR. Coenzyme Q10. In A Textbook of Natural Medicine, by JE Pizzorno, MT Murray. Seattle: Bastyr University Press, 1998, V:CoQ10–1–8. [review].
5. 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.
6. 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.
7. Morisco C, Trimarco B, Condorelli M. Effect of coenzyme Q10 in patients with congestive heart failure: a long-term multicenter randomized study. Clin Invest 1993;71:S134–6.
8. 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.
9. Gaby AR. The role of coenzyme Q10 in clinical medicine: part II. Cardiovascular disease, hypertension, diabetes mellitus and infertility. Alt Med Rev 1996;1:168–75 [review].
10. 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.
11. 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.
12. Mortensen SA. Perspectives on therapy of cardiovascular diseases with coenzyme Q10 (ubiquinone). Clin Invest 1993;71:s116–23 [review].
13. 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;33:14551.
14. 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.
15. 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].
16. Folkers K, Shizukuishi S, Takemura K, et al. Increase in levels of IgG in serum of patients treated with coenzyme Q10. Res Comm Pathol Pharmacol 1982;38:335–8.
17. 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 Comm 1995;212:172–7.
18. Digiesi V, Cantini F, Bisi G, et al. Mechanism of action of coenzyme Q10 in essential hypertension. Curr Ther Res 1992;51:668–72.
19. Gaby AR. The role of coenzyme Q10 in clinical medicine: part II. Cardiovascular disease, hypertension, diabetes mellitus and infertility. Alt Med Rev 1996;1:168–75 [review].
20. 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.
21. 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.
22. Chopra RK, Goldman R, Sinatra ST, Bhagavan HN. Relative bioavailability of coenzyme Q10 formulations in human subjects. Internat J Vit Nutr Res 1998;68:109–13.
23. 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.
24. 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 Comm 1994;199:1504–8.
25. 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 Comm 1995;212:172–7.
26. Judy WV. Nutritional intervention in cancer prevention and treatment. American College for Advancement in Medicine Spring Conference, Ft. Lauderdale, FL. May 3, 1998.

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