Coenzyme Q10 or ubiquinone is a natural substance synthesized in the body which can be increased by supplementation.  CoQ10 supplements have been of some benefit for heart attack victims, congestive heart failure, age-related macular degeneration,  patients awaiting heart transplants, and high blood pressure, although more studies are needed.  There is promising research for Parkinson's Disease, and a number of other difficulties.  CoQ10 has few side-effects, appears effective for the above conditions, and is fairly inexpensive ($13/month).  Unfortunately, because it is not a patented medicine with a high profit margin, no long-term studies have been done on its impact on stroke, heart disease, or longevity.  The total amount of research is modest and mostly focused on heart failure and hypertension.

Exercise tolerance may be increased by Co-Q10 but it does not to be of as much benefit for athletes.  Single studies report finding evidence of benefit for periodontal disease, chronic migraine headaches and type 2 diabetes.  Co-Q10 skin creams help decreasing skin aging and some report it of value for acne, although I have found no research on this issue.  Idebenone, a short chain analogue of Co-Q10, didn't help Alzheimer's disease in a very large study.

CoQ10 was first discovered in 1957 at the University of Wisconsin.  It is a coenzyme for at least three mitochondrial enzymes as well as a coenzyme for other parts of the cell.  It was first used for congestive heart failure by Italian researchers.  The Japanese developed the method of mass production and all of the CoQ10 used today is manufactured in Japan.  Deficiencies are common in a variety of diseases, but whether they are the cause of any disease is unknown.  Statin medications block biosynthesis and lead to deficiencies which can be corrected by supplementation.

The usual amount of supplementation is 100 mg/day, although some people need 200-300 mg/day to reach normal blood levels.  CoQ10 has no known drug interactions, side-effects, or toxicity.  One pound of sardines, two pounds of beef, or two and one half pounds of peanuts provide only 30 mg of CoQ10.  No one knows whether CoQ10 would prevent any illness, since research has only been with treatment of disease.

Animal foods that contain mitochondria, including meat and fish, are whole-food sources of Co-Q10. Beef heart and liver are some of the richest sources; eggs offer negligible amounts. The human body synthesizes most of its Co-Q10 in a complex process that converts the amino acid tyrosine into Co-Q10, with the help of eight vitamins and several trace minerals. People with type 2 diabetes are better able to control their blood sugar levels while taking Co-Q10 (European Journal of Clinical Nutrition, 2002, vol. 56, no. 11). Chronic migraine sufferers experience a reduction in migraine frequency while taking Co-Q10 (Cephalalgia, 2002, vol. 22, no. 2). Many athletes have tried Co-Q10 hoping to improve endurance, but the research does not strongly support that outcome. Co-Q10 can also be applied directly to the skin, where it protects against the aging effects of free radicals. Research with cosmetic creams containing Co-Q10 confirms that it can prevent visual signs of aging (Biofactors, 1999, vol. 9, no. 2). One of my middle-aged patients reported that her dermatologist recommended Co-Q10 for her acne. She tried it, experienced considerable benefit, stopped it and had her acne recur, and restarted it with renewed benefit. Several skin creams contain Co-Q10 and are sold for acne and removing fine skin lines, but I have not seen any research on the acne.

CoQ10 Summary: CoQ10 (Coenzyme Q10) serves as an electron carrier within the mitochondrial respiratory chain (MRC), where it is integrally involved in oxidative phosphorylation and consequently ATP production. HMG-CoA reductase is the rate-controlling enzyme in CoQ10 biosynthesis. Usual dietary intake together with normal in vivo synthesis seems to fulfill the demands for Q10 in healthy individuals. The importance of Q10 supplementation for general health has not been investigated in controlled experiments. The literature allows no firm conclusions about the significance of Q10 in physical activity. In different cardiovascular diseases, including cardiomyopathy, relatively low levels of Q10 in myocardial tissue have been reported. Positive clinical and hemodynamic effects of oral Q10 supplementation have been observed in double-blind trials, especially in chronic heart failure. No important adverse effects have been reported from experiments using daily supplements of up to 200 mg Q10 for 6-12 months and 100 mg daily for up to 6 years. Eur J Clin Nutr 1999 Oct;53(10):764-70. No decrease in blood in Alzheimer's disease or Coronary Heart Disease although Q10 is promoted by herbal community at "Alzheimer Prevention Center" in Tucson. Altern Ther Health Med 1998 Nov;4(6):38-43. Co-Q10 (2,3 dimethyl-5 methyl-6-decaprenyl benzoquinone) is an endogenous antioxidant found in small amounts in meats and seafood. Although Co-Q10 is found in all human cells, its highest concentrations occur in the heart, liver, kidneys, and pancreas. It is highly lipophilic. Fetrow's list of possible adverse reactions to Co-Q10 includes anorexia, diarrhea, epigastric discomfort, ischemic tissue damage [tissue damage due to a deficiency in blood in a specific part of the body] (during intense exercise), and mild nausea although side-effects are very uncommon.

CoQ10 Review Very Positive for Heart Failure, Exercise Tolerance, and Blood Pressure: Of 11 studies measuring the impact of CoQ10 on exercise capacity, six found modest positive effects and five found no impact. Of eight studies giving CoQ10 for hypertension, the average BP decrease was 16 systolic and 10 diastolic with no side-effects. The authors did a DB PC study of 35 patients with heart failure for 3 months. CoQ10 made a significant improvement in disability class and a trend toward higher exercise tolerance. A review of nine DB studies of heart failure found trends toward higher ejection fraction and lower mortality but an inadequate number of patients in total to draw firm conclusions. Systematic review of effect of coenzyme Q{10} in physical exercise, hypertension and heart failure. Rosenfeldt F, Hilton D, Pepe S, Krum H. Biofactors. 2003;18(1-4):91-100.

Cost: In January, 2004, I was able to purchase 120 mg capsules for 42 cents each. At one capsule a day, that's $12.60 per month.

CoQ10 Once a Day Dosing: Once daily 50 mg dose increased AM blood level by 55%. With a sustained release version, this increased to 120% after 15 days of treatment. Total coenzyme Q10 concentrations in Asian men following multiple oral 50-mg doses administered as coenzyme Q10 sustained release tablets or regular tablets. Lu WL, Zhang Q, et al. Biol Pharm Bull. 2003 Jan;26(1):52-5. (Ed: This suggests that once a day dosing with standard preparation may be as good as half as much twice a day.). Beijing Univ

Alzheimer's: Idebenone No Value in Large DB: Idebenone is a powerful anti-oxidant and short chain analogue of coenzyme Q-10. A very large 536-patient DB PC trials of patients with probable Alzheimer's disease and MMSE scores 12-25 using three different doses up to 360 mg t.i.d. found no evidence of clinically significant benefit. UCSD. Idebenone treatment fails to slow cognitive decline in Alzheimer's disease. Thal LJ, Grundman M, Berg J, Ernstrom K, Margolin R, Pfeiffer E, Weiner MF, Zamrini E, Thomas RG. Neurology. 2003 Dec 9;61(11):1498-1502. Ed: Idebenone is an expensive supplement ($40 for 30 150 mg. tablets) available without prescription and heavily promoted for dementia, heart disease, and much else. It has been found of modest benefit in a 1-year DB PC study of cardiomyopathy in Friedreich's Ataxia but doesn't slow the progression of the ataxia. Neurology. 2003 May 27;60(10):1676-9. Co Q-10, in contrast, is much less expensive and has been found of some value for heart attack victims and for high blood pressure in DB studies.

Alzheimer's: Idebenone Said to Help Dementia in Small DB: In an older 1994 92-patient DB PC 3 month study by the Univ. of Turin, idebenone patients had their dementia progress more slowly. Idebenone, a new drug in the treatment of cognitive impairment in patients with dementia of the Alzheimer type. Bergamasco B, Scarzella L, La Commare P. Funct Neurol. 1994 May-Jun;9(3):161-8

Asthma: Reduced Steroid Dosage: Long-term administration of corticosteroids has been shown to result in mitochondrial dysfunction and oxidative damage of mitochondrial and nuclear DNAs. There are decreased coenzyme Q(10) (CoQ(10)) and alpha-tocopherol concentrations in plasma and blood in corticosteroid-dependent bronchial asthma patients. In an open, 16-week per cross-over, randomized study with 41 bronchial asthma patients, addint to standard antiasthmatic therapy CoQ(10) as Q-Gel (120 mg) + 400 mg alpha-tocopherol + 250 mg vitamin C a day found a reduction in the dosage of corticosteroids required by the patients following antioxidant supplementation. Coenzyme Q10 supplementation reduces corticosteroids dosage in patients with bronchial asthma. Gvozdjakova A, et al. Comenius University, Bratislava, Slovakia. .  Biofactors 2005;25(1-4):235-40.

Asthma: CoQ10 Low: 51 adult asthmatics vs. 25 controls. Concentrations of CoQ10 and alpha-tocopherol, decreased significantly both in plasma and whole blood, compared with healthy volunteers (p < 0.009, p < 0.004; p < 0.035, p < 0.001, respectively). Levels of coenzyme Q10 in asthmatics. Gazdik F, Gvozdjakova A, et al. Bratisl Lek Listy 2002;103(10):353-6

Cancer of the Prostate: CoQ10 and Anti-Oxidants Vitamins C and E and Selenium No Help: In a 21-week study of 80 patients with untreated prostate cancer and rising PSA levels, vitamin E, selenium, vitamin C, coenzyme Q10 had no significant effect on serum levels of PSA, testosterone, dihydrotestosterone, luteinizing hormone or sex hormone binding globulin (p>0.2). Effect of a nutritional supplement containing vitamin E, selenium, vitamin c and coenzyme Q10 on serum PSA in patients with hormonally untreated carcinoma of the prostate: a randomised placebo-controlled study. Hoenjet KM, Dagnelie PC, et al. University Hospital of Maastricht, The Netherlands. Eur Urol. 2005 Apr;47(4):433-9; discussion 439-40.

Cerebellar Ataxia: CoQ10 Deficiency in Some: Muscle biopsies were taken from 135 patients with genetically undefined cerebellar ataxia. Thirteen patients with childhood-onset ataxia and cerebellar atrophy had markedly decreased levels of CoQ10. Associated symptoms included seizures, developmental delay, mental retardation, and pyramidal signs. Neurology 2003 Apr 8;60(7):1206-8. Neurology 2003 Apr 8;60(7):1206-8. Cerebellar ataxia and coenzyme Q10 deficiency. Lamperti C, Naini A, et al.

Chronic Fatigue Syndrome: CoQ10 Said to Help: In a very small study by Judy (1996) of 20 females with Chronic Fatigue Syndrome who required bed rest following mild exercise and 20 healthy controls, 80% of the Chronic Fatigue Syndrome patients were found to be deficient in CoQ10, which further decreased following mild exercise or over the course of normal daytime activity. After 3 months of CoQ10 supplementation (100 mg/day), the exercise tolerance (400 kg-meters of work) of the Chronic Fatigue Syndrome patients more than doubled. All patients had improved: 90% had reduction and/or disappearance of clinical symptoms, and 85% had decreased postexercise fatigue (Judy WV 1996). CDC website 10/4/04. Ed: While I did find two early studies by Judy with CoQ10, PubMed doesn't list this one.

Chronic Fatigue Syndrome: CoQ10, DHEA, Ginseng Used: In an uncontrolled, prospective study of 155 adults with chronic fatigue, 87% were female and 79% were middle-aged. The median duration of fatigue was 6.7 years. The percentage of users who thought a treatment helpful was greatest for coenzyme Q10 (69% of 13 subjects), dehydroepiandrosterone (DHEA) (65% of 17 subjects), and ginseng (56% of 18 subjects). Treatments at 6 months that predicted subsequent fatigue improvement were vitamins (p = .08), vigorous exercise (p = .09), and yoga (p = .002). Magnesium (p = .002) and support groups (p = .06) were strongly associated with fatigue worsening from 6 months to 2 years. Prospective observational study of treatments for unexplained chronic fatigue. Bentler SE, Hartz AJ, Kuhn EM. University of Iowa. J Clin Psychiatry. 2005 May;66(5):625-32.

Diabetes: CoQ10 Helped in Very Small Study: In a 12-week DB PC study of 40 diabetics, Coenzyme Q10 200 mg/day lower glycated hemoglobin. Eur J Clin Nutr 56:1137, 2002

Eye: Macular Degeneration: Carnitine-CoQ10 Combo May Help: Mitochondria and peroxisomes of the retinal pigment epithelium may play a central role in causing age-related macular degeneration (AMD). 14 adults with early AMD were treated with acetyl-L-carnitine (ALC), polyunsaturated fatty acids (PUFAs), coenzyme Q10 (CoQ10) and vitamin E, while 14 others were treated with vitamin E only. In the treated group, all the visual functions showed slight improvement which was evident after 3 months of treatment and remained nearly stationary for 24 months. The control group showed slow worsening although the difference never became statistically significant due to the small number of patients involved. Mitotropic compounds for the treatment of age-related macular degeneration. The metabolic approach and a pilot study. Feher J, Papale A, Mannino G, Gualdi L, Balacco Gabrieli C. University of Rome La Sapienza. Ophthalmologica. 2003 Sep-Oct;217(5):351-7 

Eye: Age-Related Macular Degeneration Helped: In a 12-month DB PC study of 106 adults with early AMD,those given a combination of acetyl-L-carnitine, n-3 fatty acids, and coenzyme Q10 has improves in visual field mean defects, visual acuity, foveal sensitivity, and fundus alterations for AMD. In the treated group only 2% deteriorated vs. 17% for placebo (p = 0.006, odds ratio: 10.93). Decrease in drusen-covered area of treated eyes was also statistically significant. Feher J et al. University of Rome 'La Sapienza', Italy. Ophthalmologica. 2005 May-Jun;219(3):154-66 

Migraines: CoQ10 Helped: Riboflavin, which improves energy metabolism similarly to coenzyme Q10 (CoQ10), is effective in migraine prophylaxis. In a 3-month DB PC study of 42 migraine sufferers, those on CoQ10 (3 x 100 mg/day) had lower attack-frequency, headache-days and days-with-nausea in the third treatment month; 50%-responder-rate for attack frequency was 14.4% for placebo and 47.6% for CoQ10 (number-needed-to-treat: 3). Efficacy of coenzyme Q10 in migraine prophylaxis: A randomized controlled trial. Sandor PS, Di Clemente L, et al. University Hospital Zurich, Switzerland. Neurology. 2005 Feb 22;64(4):713-5.

Mitochondrial Myopathies: CoQ10 Helps: 44 patients were treated in an open trial; 16 had at least a 25% decrease post-exercise lactate. These were entered into DB PC and helped by 2 mg/kg/d. Bresolin, U Milan, J Neurol Sci 12/90:100:70

Parkinson’s Disease Slowed by High Dose CoQ10: 1% Americans over 65 have Parkinson's. Coenzyme Q10 is low in Parkinson's. CoQ10 helps function of mitochondria and is a potent anti-oxidant. UCSD Arch Neurol 10/15/02 59:1541. Clifford W Shults found 1200 mg/day ($120/mo) slowed disease progression over 16 month study by 44%, but 300 and 600/day were ineffective. DB 80 patient pilot study looking at symptom progression. Effects of coenzyme Q10 in early Parkinson disease: evidence of slowing of the functional decline. Shults CW, Oakes D, et al; Parkinson Study Group. Arch Neurol 2002 Oct;59(10):1541-50. Idiopathic Parkinson's disease (PD) is characterized by a systemic loss of activity of complex I (NADH:ubiquinone oxidoreductase), the target enzyme of the parkinsonism producing neurotoxin, MPTP. ND5 is a mitochondrial gene encoding a complex I subunit.  In brain tissue from PD and controls, the presence or absence of amino acid changing mutations correctly classified 15 of 16 samples. Heteroplasmic mutations in a specific region of ND5 may be of major pathogenic importance in idiopathic PD. Biochem Biophys Res Commun. 2005 Jan 21;326(3):667-9

Parkinson’s: CoQ10 Modest Benefit: A DB 4 week study using 360 mg/d. Ruhr Univ, Coenzyme Q10 supplementation provides mild symptomatic benefit in patients with Parkinson's disease. Muller T, Buttner T, Gholipour AF, Kuhn W. Neurosci Lett. 2003 May 8;341(3):201-4

Peridontal Disease: Coenzyme Q10 May Help: An 18 patient DB PC trial found significant benefit from CoQ10. Wilkinson, Res Commun Chem Pathol Pharmacol 8/76;14:715. Coenzyme Q10=ubiquinone

Pre-eclampsia CoQ10 45% Lower Than in Normal Pregnancies: CoQ10 is normally increased by 30% in normal pregnancy. An Equador study found it decreased with pre-eclampsia. Free Radic Biol Med. 2003 Dec 1;35(11):1453-6

Supplementation Increases Blood Level 110%: A DB PC study of 99 healthy men given CoQ10 30 mg, 100 mg or placebo once a day for two months found the higher dose increased the blood level. Biofactors. 2003;18(1-4):185-193

Exercise

CoQ10, Cytochrome C, Inosine No Benefit Athletic Performance: DB PC crossover 4 weeks each for trained athletes taking pill with 100 mg Q10, 500 cytochrome C, 100 mg inositine, 200 IU Vit E TID. No benefit athletic performance. Snider, Int J Sports Nutr 92;2:272

CoQ10 Helped Cross Country Skiers: DB PC crossover with 25 top skiers improved on performance and feeling of benefit. Ylikoski, Mol Aspect Med ’97;18 Suppl:283

CoQ10 No Help for Cyclists and Triathletes: No evidence of benefit on several measures in 18 adults. Weston, Australia. Int J Sport Nutr 9/97;7:197

Exercise Muscle Damage: CoQ10 Not Help: 90 mg of Q10 plus 13.5 mg vitamin E for 3 week before marathon had no benefit on oxidation of lipoproteins or muscle damage. Kaikkonen, Finland, Free Radic Res 7/98;29:85

Muscle Repair Helped in Pig Study: The course of regeneration of bupivacaine-damaged muscle is affected to a higher extent by coenzyme Q10 than by vitamin E. Pol J Vet Sci. 2004;7(4):295-303

Longevity

CoQ10 and Alpha-Lipoic Acid Failed Increase Lifespan of Mice: Supplemental alpha-lipoic acid (LA) or coenzyme Q(10) (CQ) and caloric restriction (CR, a positive control) had no impact on longevity or tumor patterns compared with control mice fed the same number of calories, whereas CR increased maximum life span by 13% (p <.0001) and reduced tumor incidence. The impact of alpha-lipoic acid, coenzyme Q10 and caloric restriction on life span and gene expression patterns in mice. Lee CK, Pugh TD, Klopp RG, Edwards J, Allison DB, Weindruch R, Prolla TA. University of Wisconsin. Free Radic Biol Med. 2004 Apr 15;36(8):1043-57

CoQ10 Helped Rats Live Longer on High Omega-3 Diet: Long-term supplementation with coenzyme Q(10) in rats might attenuate oxidative alterations related to PUFA-rich diets, which would allow to preserve beneficial aspects of PUFA on health avoiding their deleterious aspects. Supplemented animals showed higher concentration of coenzyme Q(10) in liver mitochondria, lower levels of DNA double-strand breaks in peripheral blood lymphocytes. Animals supplemented on coenzyme Q reached a significantly higher mean life span (11.7% higher, i.e., 2.5 months) and a significantly higher maximum life span (24% higher, i.e., 6 months) than non-supplemented animals. Coenzyme Q supplementation protects from age-related DNA double-strand breaks and increases lifespan in rats fed on a PUFA-rich diet. Quiles JL, Ochoa JJ, Huertas JR, Mataix J. University of Granada. Exp Gerontol. 2004 Feb;39(2):189-94

CoQ10 Kills Fruit Flies: Both coenzyme Q10 and nicotinamide in large doses successfully reversed bioenergy changes in aged Drosophila. However, only nicotinamide was able to reduce short term mortality and increase life span, whereas coenzyme Q10 increased mortality and reduced life span. Production of reactive oxygen species (ROS) was increased in coenzyme Q10 treated flies, whereas nicotinamide reduced ROS production. Biogerontology 2002;3(1-2):103-6

Coenzyme Q(10) and Alpha-tocopherol Together, Not Alone, Improve Learning in aged mice. McDonald SR, et al. Free Radic Biol Med. 2005 Mar 15;38(6):729-36

Case of drug-induced pneumonitis associated with a dietary supplement containing CoQ10. Nihon Kokyuki Zasshi 2006 Oct;44(10):766-70.