Coenzyme Q10

 
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Coenzyme Q10
Coenzyme Q10

Background

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, but remains controversial as a treatment in many areas.

 

Synonyms

AndelirŽ, CoenzymeQ, Co-enzyme Q10, Coenzyme Q (50), CoQ, CoQ10, CoQ(50), Co-Q10, CoQ-10, 2,3 dimethoxy-5 methyl-6-decaprenyl benzoquinone, HeartcinŽ, idebenone (synthetic analogue), mitoquinone, NeuquinoneŽ, Q10, TaidecanoneŽ, ubidecarenone, ubiquinone, ubiquinone-10, ubiquinone-Q10, UdekinonŽ, 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 Grade*
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. Well-designed long-term research is needed to strengthen this recommendation.

B
Alzheimer's disease

Promising preliminary evidence 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 these results before a firm recommendation can be made.

C
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.

C
Anthracycline chemotherapy heart toxicity

Anthracycline chemotherapy drugs, such as doxorubicin (AdriamycinŽ), 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.

C
Breast cancer

Supplementation with CoQ10 has not been proven to reduce cancer, and has not been compared to other forms of treatment for breast cancer.

C
Cardiomyopathy (dilated, hypertrophic)

There is conflicting evidence from research on the use of CoQ10 in patients with dilated or hypertrophic cardiomyopathy. Better research is needed in this area before a recommendation can be made.

C
Exercise performance

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.

C
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.

C
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. Better research is needed before a conclusion can be drawn.

C
Heart attack (acute myocardial infarction)

There is preliminary human study of CoQ10 given to patients within three days after a heart attack. Better research is needed before a firm conclusion can be drawn.

C
Heart conditions (mitral valve prolapse in children)

There is early data to support the use of CoQ10 in children with mitral valve prolapse. Well-designed clinical trials are needed before a recommendation can be made.

C
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). Better research is needed in this area, studying effects on quality of life, hospitalization, death rates, before a recommendation can be made.

C
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 are necessary before a recommendation can be made.

C
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.

C
Increasing sperm count (idiopathic spermatozoa)

There is early evidence that supports the use of CoQ10 in the treatment of increasing sperm count and motility. Better studies are needed before a strong recommendation can be made.

C
Kidney failure

There is initial data to support the use of CoQ10 in the treatment of kidney (renal) failure. More research is needed before a recommendation can be made.

C
Migraine

There is fair evidence to support the use of CoQ10 treatment in migraine prevention or treatment. However, more well-designed studies are needed to confirm these findings.

C
Mitochondrial diseases and Kearns-Sayre syndrome

CoQ10 is often recommended for patients with mitochondrial diseases, including myopathies, encephalomyopathies, and Kearns-Sayre syndrome. Better studies are needed before a strong recommendation can be made.

C
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.

C
Parkinson's disease

There is promising human evidence for the use of CoQ10 in the treatment of Parkinson's disease. Better-designed trials are needed to confirm these results.

C
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.

D
Huntington's disease

There is negative evidence from studies that used CoQ10 in the treatment of Huntington's disease.

D

 

*Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use;
F: Strong scientific evidence against this use.

 

Grading rationale

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.

Abnormal heart rhythms, amyotrophic lateral sclerosis (ALS), antioxidant, asthma, atherosclerosis, Bell's palsy, blood flow disorders, breathing difficulties, cancer, cerebellar ataxia, chronic fatigue syndrome, chronic obstructive pulmonary disease (COPD), deafness, gingivitis, hair loss (and hair loss from chemotherapy), hepatitis B, high cholesterol, immune system diseases, infertility, insomnia, leg swelling (edema), life extension, liver enlargement or disease, lung cancer, lung disease, macular degeneration, MELAS syndrome, metastatic disease, MIDD (maternally inherited diabetes mellitus and deafness), muscle wasting, nutrition, obesity, Papillon-Lefevre Syndrome, 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, swelling.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older)
50-1200 milligrams of CoQ10 have been taken in divided doses by mouth daily.

 

85 milligrams of CoQ10 per milliliter of soybean oil suspension has been applied to the surface of affected areas once weekly using a plastic syringe for gum disease.

 

Most studies of CoQ10 for heart protection during bypass surgery have used CoQ10 taken by mouth. One study used intravenous CoQ10, 5 milligrams per kilogram of body weight, given two hours prior to surgery. Safety is not clear. Any therapies used close to the time of surgery should be discussed with the surgeon and a pharmacist prior to starting.

 

Children (younger than 18 years)
There is not enough scientific information to recommend the safe use of CoQ10 in children. A qualified healthcare provider should be consulted before considering use.

 

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies
In theory, allergic reactions to supplements containing CoQ10 may occur.

 

Side Effects and Warnings
There are few serious reported side effects of CoQ10. Side effects are typically mild and brief, stopping without any treatment needed. Reactions may include nausea, vomiting, stomach upset, heartburn, diarrhea, loss of appetite, skin itching, rash, insomnia, headache, dizziness, irritability, increased light sensitivity of the eyes, fatigue, or flu-like symptoms.

 

CoQ10 may lower blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Serum glucose levels may need to be monitored by a healthcare provider, and medication adjustments may be necessary.

 

Low blood platelet number was reported in one person taking CoQ10. However, other factors (viral infection, other medications) may have been responsible. Lowering of platelets may increase the risk of bruising or bleeding, although there are no known reports of bleeding from CoQ10. Caution is advised in people who have bleeding disorders or who are taking drugs that increase the risk of bleeding. Dosing adjustments may be necessary.

 

CoQ10 may decrease blood pressure, and caution is advised in patients with low blood pressure or taking blood pressure medications. Elevations of liver enzymes have been reported rarely, and caution is advised in people with liver disease or taking medications that may harm the liver. CoQ10 may lower blood levels of cholesterol or triglycerides. Thyroid hormone levels may be altered based on one study.

 

Organ damage due to lack of oxygen/blood flow during intense exercise has been reported in a study of patients with heart disease, although the specific role of CoQ10 is not clear. Vigorous exercise is often discouraged in people using CoQ10 supplements.

 

Pregnancy and Breastfeeding
There is not enough scientific evidence to support the safe use of CoQ10 during pregnancy or breastfeeding.

 

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs
In theory and based on a human case report, coenzyme Q10 may reduce the effectiveness of warfarin (CoumadinŽ), and may limit or prevent effective anticoagulation (blood "thinning"). CoQ10 may reduce blood pressure and may add to the effects of other blood pressure lowering drugs. In theory, CoQ10 may affect thyroid hormone levels and alter the effects of thyroid drugs such as levothyroxine (SynthroidŽ), although this has not been proven in humans.

 

Based on theory and human research, a number of drugs may deplete natural levels of CoQ10 in the body. It has not been shown that there are benefits of CoQ10 supplements in people using these agents. Examples include: diabetes drugs, tricyclic antidepressants, antipsychotics, beta-blockers, HMG-CoA reductase inhibitors ("statins"), and diuretic drugs ("water pills").

 

Interactions with Herbs and Dietary Supplements
CoQ10 may reduce blood pressure and may result in additive effects when taken with other herbs or supplements that also lower blood pressure. Diuretic herbs such as licorice and horsetail may also decrease blood pressure and therefore interact with CoQ10.

 

Vitamin E may reduce CoQ10 blood levels. In theory, red rice yeast may decrease CoQ10 levels. CoQ10 may add to the effects or side effects of L-carnitine.

 

CoQ10 may also theoretically reduce the effectiveness of warfarin or other blood-thinning agents, such as garlic ( Allium sativum ),  Ginkgo biloba , or saw palmetto ( Serenoa repens ).

 

CoQ10 may also interact with vitamin A or vitamin C.