Coenzyme Q10 is a fat-soluble nutrient also known as CoQ10, vitamin Q10, ubidecarenone, or ubiquinone. It is a natural product of the human body that is primarily found in the mitochondria, which are the cellular organelles that produce energy. It occurs in most tissues of the human body; however, the highest concentrations are found in the heart, liver, kidneys, and pancreas.
Ubiquinone takes its name from a combination of the word ubiquitous, meaning something that is found everywhere, and quinone 10. Quinones are substances found in all plants and animals. The variety found in humans has a 10-unit side chain in its molecular structure.
Apart from the important process that provides energy, CoQ10 also stabilizes cell membranes and acts as an antioxidant. In this capacity, it destroys free radicals, which are unstable molecules that can damage normal cells.capacity, it destroys free radicals, which are unstable molecules that can damage normal cells.
It appears to improve patient health and wellbeing, and to increase cardiac efficiency. The dosage generally recommended for this condition is 100–300 mg a day, preferably in divided doses. According to Dr. Karl Folkers in Prevention’s Healing with Vitamins, it takes one to three months to achieve desired results from supplementation, and as long as six months to attain maximum benefit.
CoQ10 may also help people with some forms of cardiomyopathy. Patients should consult their physician about the possible benefits of supplementation for this condition.
The usefulness of CoQ10 in lowering blood pressure is not well documented. The supplement is helpful for hypertension. The dose recommended is 200–250 mg a day, with results taking several months to appear. It is possible that some patients with essential hypertension who are initially low in CoQ10 may eventually be able to decrease the amount of their other blood pressure medications. This must be done under the care of a health care provider.
Oral supplementation of CoQ10 has been shown to improve periodontal disease, as it decreases the size of abnormally deep pockets in the gums, and also reduces the extent of bacterial contamination.
Other possible benefits of CoQ10 are to decrease angina symptoms, improve immune function in patients with AIDS and other immune deficiencies, improve control of blood sugar, lower cholesterol, improve physical stamina, and help people with muscular dystrophy and Huntington’s disease.
A group of researchers at the University of California at San Diego reported in 2002 that coenzyme Q10 appears to slow the progress of Parkinson’s disease, Friedreich’s ataxia, and other conditions marked by degeneration of the central nervous system.
The supplement can also reduce the toxicity of some types of chemotherapy. Doxorubicin, a chemotherapeutic agent, is known to sometimes damage the heart. Concomitant supplementation seems to reduce this toxic effect.
The possible benefits of CoQ10 should be discussed with a nutritionally-oriented health care provider.
Patients with certain conditions tend to have lower levels of CoQ10, and may benefit from supplements. Some diseases that are associated with decreased amounts of this nutrient are AIDS, chronic fatigue, congestive heart failure, cardiomyopathy, and inflammatory gum disease. Levels of CoQ10 tend to decrease with age; tests for its presence in the body are not widely available. Adverse effects from this supplement are rare and mild, so anyone suffering from one of the listed conditions should consider discussing supplementation with a health care provider.
Food products are a good source of CoQ10, and provide approximately half of the body’s requirement. Cold-water fish such as mackerel, salmon, sardines, and tuna are particularly high in CoQ10. Vegetable oils and meats also provide good sources. The liver manufactures adequate amounts to fulfill the need not met in the diet.
People who are deficient in B vitamins, selenium, vitamin C, and vitamin E may not be able to make as much CoQ10 as they need because these nutrients are required for production.
Consumption of foods rich in CoQ10 and production of the nutrient in the liver will not provide the amounts needed to treat heart failure and other conditions that may contribute to a deficiency of this nutrient. In those cases, supplements are required.
Supplements of CoQ10 are widely available; however, its cost varies considerably. As of 2013, it is available in the United States, ranging in price from $5.99 for a bottle of 30 100-mg capsules to $40 for a bottle of 120 100-mg softgels. It is found in various forms including capsules, gelcaps, liquids, and tablets. The latter may be the best choice, as this form generally includes a source of fat that improves absorption. Vitamin E is a helpful stabilizing additive as well.
Preparations may have added vitamins, herbs, amino acids, minerals, or other compounds. Most of the CoQ10 products currently available on the market are manufactured in Japan.
Like other supplements, Co10 is best kept in a cool, dry place, out of direct light, and out of the reach of children.
As of 2013, the safety of CoQ10 for pregnant or breast-feeding women has not been established, and its use is not recommended under these conditions. It is also not recommended for young children. People diagnosed with heart failure, diabetes, kidney problems, or liver disease should use particular care with this supplement, as the dosage of other medications may require adjustment. These individuals should consult a physician before taking coenzyme Q10.
Reported adverse effects related to supplemental CoQ10 use include diarrhea, irritation of the stomach, poor appetite, insomnia, dizziness, nausea, sensitivity to light, irritability, headach, and exhaustion. These effects are rarely reported and are mild. CoQ10 is considered extremely safe for most people. If doses over 300 mg per day are taken, liver enzyme levels may be affected, and may need monitoring.
It is possible that CoQ10 decreases the action of sodium warfarin (known by the brand name Coumadin), which is prescribed to prevent the formation of blood clots in patients at risk of heart attack or stroke.
Some oral diabetes medications may also interfere with the action of CoQ10. Cholesterol-lowering drugs in the statin group may have this effect as well. Persons with bleeding disorders should be cautious in using CoQ10.
Caution is also advised in patients with low blood pressure or those taking low blood pressure medications.
Although the role of CoQ10 is unclear, organ damage from lack of oxygen or decreased blood flow to the heart has been reported in patients with heart disease, thus vigorous exercise is not recommended for those taking CoQ10.
Research and general acceptance
Preclinical studies in animals have found that CoQ10 boosts immune function and helps the body fight some infections and some cancers, helps to protect the heart during treatment with the anticancer drug doxorubicin, and may act to stop cancerous cells from growing.
Small clinical studies were done on breast cancer patients with promising results. In a study of 32 patients, some symptoms of cancer disappeared in six of the patients, and researchers reported that all studied patients used less pain medication, maintained their weight during treatment, and experienced an improved quality of life.
Further studies by the same authors reported a remission of cancer for several patients after high doses of CoQ10. More research is needed, however, as these studies were not randomized or controlled, and patients received standard treatment in addition to CoQ10.