Coenzyme Q10

by MedlinePlus

Coenzyme Q10 (CoQ10) is produced by the human body and is necessary for the basic functioning of cells. CoQ10 levels are reported to decrease with age and to be low in patients with some chronic diseases such as heart conditions, muscular dystrophies, Parkinson's disease, cancer, diabetes, and HIV/AIDS. Some prescription drugs may also lower CoQ10 levels. Levels of CoQ10 in the body can be increased by taking CoQ10 supplements, although it is not clear that replacing "low CoQ10" is beneficial. CoQ10 has been used, recommended, or studied for numerous conditions, and remains controversial as a treatment in many areas.

Synonyms

Andelir®, CoenzymeQ, Co-enzyme Q10, Coenzyme Q (50), CoQ, CoQ10, CoQ(50), Co-Q10, CoQ-10, 2,3 dimethoxy-5 methyl-6-decaprenyl benzoquinone, Heartcin®, idebenone (synthetic analogue), mitoquinone, Neuquinone®, Q10, Taidecanone®, ubidecarenone, ubiquinone, ubiquinone-10, ubiquinone-Q10, Udekinon®, vitamin q10, vitamin Q10.

Evidence

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Uses based on scientific evidence

High blood pressure (hypertension)

Preliminary research suggests that CoQ10 causes small decreases in blood pressure (systolic and possibly diastolic). Low blood levels of CoQ10 have been found in people with hypertension, although it is not clear if CoQ10 "deficiency" is a cause of high blood pressure. It is not known what dose is safe or effective. CoQ10 is less commonly used to treat hypertension than it is for other heart conditions such as congestive heart failure. Well-designed long-term research is needed to strengthen this recommendation.

Alzheimer's disease

Promising preliminary evidence from human research suggests that CoQ10 supplements may slow down, but not cure, dementia in people with Alzheimer's disease. Additional well-designed studies are needed to confirm this result before a firm recommendation can be made.

Angina (chest pain from clogged heart arteries)

Preliminary small human studies suggest that CoQ10 may reduce angina and improve exercise tolerance in people with clogged heart arteries. Better studies are needed before a firm recommendation can be made.

Anthracycline chemotherapy heart toxicity

Anthracycline chemotherapy drugs, such as doxorubicin (Adriamycin®), are commonly used to treat cancers such as breast cancer or lymphoma. Heart damage (cardiomyopathy) is a major concern with the use of anthracyclines, and CoQ10 has been suggested to protect the heart. However, studies in this area are small and not high quality and the effects of CoQ10 remain unclear.

Breast cancer

Several studies in women with breast cancer report reduced levels of CoQ10 in diseased breast tissue or blood. It has been suggested by some researchers that raising CoQ10 levels with supplements might be helpful. However, it is not clear if CoQ10 is beneficial in these patients, or if the low levels of CoQ10 may actually be a part of the body's natural response to cancer, helping to fight disease. Supplementation with CoQ10 has not been proven to reduce cancer, and has not been compared to other forms of treatment for breast cancer.

Cardiomyopathy (dilated, hypertrophic)

There is conflicting evidence from research on the use of CoQ10 in patients with dilated or hypertrophic cardiomyopathy. Different levels of disease severity have been studied (New York Heart Association heart failure classes I through IV). Some studies report improved heart function (ejection fraction, stroke volume, cardiac index, exercise tolerance), while others find no improvements. Most trials are small or not well designed. Better research is needed in this area before a recommendation can be made.

Exercise performance

The effects of CoQ10 on exercise performance have been tested in athletes, normal healthy individuals, and in people with chronic lung disease. Results are variable, with some research suggesting benefits, and other studies showing no effects. Most trials have not been well-designed. Better research is necessary before a firm conclusion can be drawn.

Friedreich's ataxia

Preliminary research reports promising evidence for the use of CQ10 in the treatment of Friedreich's ataxia. Further evidence is necessary before a firm conclusion can be drawn.

Gum disease (periodontitis)

Preliminary human studies suggest possible benefits of CoQ10 taken by mouth or placed on the skin or gums in the treatment of periodontitis. Improvements in bleeding, swelling, and pain are reported. However, available studies are small and not high quality. Better research is needed before a conclusion can be drawn.

Heart attack (acute myocardial infarction)

There is preliminary human study of CoQ10 given to patients within three days after a heart attack. Reductions in deaths, abnormal heart rhythms, and second heart attacks are reported, although better research is needed before a firm conclusion can be drawn.

Heart failure

The evidence for CoQ10 in the treatment of heart failure is controversial and remains unclear. Different levels of disease severity have been studied (New York Heart Association classes I through IV). Several studies have shown benefits of coenzyme Q10 in people who have been diagnosed with chronic heart failure (with or without cardiomyopathy), including in transplant recipients. Some studies report improved heart function (ejection fraction, stroke volume, cardiac index, exercise tolerance), while others find no improvements. Most trials are small or not well designed. In some parts of Europe, Russia, and Japan, CoQ10 is considered a part of standard therapy for congestive heart failure patients. Better research is needed in this area, studying effects on quality of life, hospitalization, death rates, before a recommendation can be made.

Heart protection during surgery

Several studies suggest that the function of the heart may be improved after major heart surgeries such as coronary artery bypass graft (CABG) or valve replacement when CoQ10 is given to patients before or during surgery. Better studies that measure effects on long-term heart function and survival are necessary before a recommendation can be made.

HIV/AIDS

There is limited evidence that natural levels of CoQ10 in the body may be reduced in people with HIV/AIDS. There is no reliable scientific research showing that CoQ10 supplements have any effect on this disease.

Mitochondrial diseases and Kearns-Sayre syndrome

COQ10 is often recommended for patients with mitochondrial diseases, including myopathies, encephalomyopathies, and Kearns-Sayre syndrome. Several early studies report improvements in metabolism and physical endurance in patients with these conditions after treatment with CoQ10, although most available research is not high quality or definitive. Better studies are needed before a strong recommendation can be made.

Muscular dystrophies

Preliminary studies in patients with muscular dystrophy taking COQ10 supplements describe improvements in exercise capacity, heart function, and overall quality of life. Additional research is needed in this area.

Diabetes

Preliminary evidence suggests that CoQ10 does not affect blood sugar levels in patients with type 1 or type 2 diabetes, and does not alter the need for diabetes medications.

Uses based on tradition or theory

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Amyotrophic lateral sclerosis (ALS), antioxidant, asthma, Bell's palsy, breathing difficulties, cancer, cerebellar ataxia, chronic fatigue syndrome, chronic obstructive pulmonary disease (COPD), deafness, decreased sperm motility (idiopathic asthenozoospermia), gingivitis, hair loss (and hair loss from chemotherapy), heart irregular beats, hepatitis B, high cholesterol, Huntington's chorea/disease, immune system diseases, infertility, insomnia, kidney failure, leg swelling (edema), life extension, liver enlargement or disease, lung cancer, lung disease, macular degeneration, MELAS syndrome, MIDD (maternally inherited diabetes mellitus and deafness), mitral valve prolapse, nutrition, obesity, Papillon-Lefevre Syndrome, Parkinson's disease,physical performance, prevention of muscle damage from "statin" cholesterol-lowering drugs, psychiatric disorders, QT-interval shortening; reduction of phenothiazine drug side effects, reduction of tricyclic antidepressant (TCA) drug side effects, stomach ulcer.

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