Coenzyme Q10

by National Cancer Institute

Overview

Coenzyme Q 10 is a compound that is made naturally in the body. The body uses it for cell growth and to protect cells from damage that could lead to cancer.

Animal studies have shown that coenzyme Q10 helps the immune system work better and makes the body better able to resist certain infections and types of cancer.

Clinical trials have shown that coenzyme Q10 helps protect the heart from the damaging side effects of doxorubicin, a drug used to treat cancer.

In 3 small studies of coenzyme Q10 in breast cancer patients, some patients appeared to be helped by the treatment. Weaknesses in study design and reporting, however, made it unclear if benefits were caused by the coenzyme Q10 or by something else (see Question 5 3).

Coenzyme Q10 may not mix safely with other treatments. It is important that patients tell their health care providers about all therapies they are currently using or thinking of using.

Coenzyme Q10 has not been carefully tested to see if it is safe and effective. Because coenzyme Q10 is sold as a dietary supplement rather than a drug, it is not regulated by the US Food and Drug Administration.

Questions and Answers About Coenzyme Q10

1. What is coenzyme Q10?

Coenzyme Q 10 is a compound that is made naturally in the body. The Q and the 10 in coenzyme Q10 refer to the groups of chemicals that make up the coenzyme. Coenzyme Q10 is also known by these other names:

• CoQ10.
• Q10.
• Vitamin Q10.
• Ubiquinone.
• Ubidecarenone.

A coenzyme helps an enzyme do its job. An enzyme is a protein that speeds up the rate at which natural chemical reactions take place in cells of the body. The body's cells use coenzyme Q10 to make energy needed for the cells to grow and stay healthy. The body also uses coenzyme Q10 as an antioxidant. An antioxidant is a substance that protects cells from chemicals called free radicals. Free radicals can damage DNA (deoxyribonucleic acid). Genes, which are pieces of DNA, tell the cells how to work in the body and when to grow and divide. Damage to DNA has been linked to some kinds of cancer. By protecting cells against free radicals, antioxidants help protect the body against cancer.

Coenzyme Q10 is found in most body tissues. The highest amounts are found in the heart, liver, kidneys, and pancreas. The lowest amounts are found in the lungs. The amount of coenzyme Q10 in tissues decreases as people get older.

2. What is the history of the discovery and use of coenzyme Q10 as a complementary or alternative treatment for cancer?

Coenzyme Q10 was first identified in 1957. Its chemical structure was determined in 1958. Interest in coenzyme Q10 as a possible treatment for cancer began in 1961, when it was found that some cancer patients had a lower than normal amount of it in their blood. Low blood levels of coenzyme Q10 have been found in patients with myeloma, lymphoma, and cancers of the breast, lung, prostate, pancreas, colon, kidney, and head and neck.

Studies suggest that coenzyme Q10 may help the immune system work better. Partly because of this, coenzyme Q10 is used as adjuvant therapy for cancer. Adjuvant therapy is treatment given following the primary treatment to increase the chances of a cure.

3. What is the theory behind the claim that coenzyme Q10 is useful in treating cancer?

Coenzyme Q10 may be useful in treating cancer because it boosts the immune system. Also, studies suggest that CoQ10 analogs (drugs that are similar to CoQ10) may prevent the growth of cancer cells directly. As an antioxidant, coenzyme Q10 may help prevent cancer from developing.

Refer to the PDQ health professional summary on Coenzyme Q10 6 for more information on the theory behind the study of coenzyme Q10 in the treatment of cancer.

4. How is coenzyme Q10 administered?

Coenzyme Q10 is usually taken by mouth as a pill (tablet or capsule). It may also be given by injection into a vein (IV). In animal studies, coenzyme Q10 is given by injection.

5. Have any preclinical (laboratory or animal) studies been conducted using coenzyme Q10?

A number of preclinical studies have been done with coenzyme Q10. Research in a laboratory or using animals is done to find out if a drug, procedure, or treatment is likely to be useful in humans. These preclinical studies are done before any testing in humans is begun. Most laboratory studies of coenzyme Q10 have looked at its chemical structure and how it works in the body. The following has been reported from preclinical studies of coenzyme Q10 and cancer:

Animal studies found that coenzyme Q10 boosts the immune system and helps the body fight certain infections and types of cancer.

Coenzyme Q10 helped to protect the hearts of study animals that were given the anticancer drug doxorubicin, an anthracycline that can cause damage to the heart muscle.

Laboratory and animal studies have shown that analogs of coenzyme Q10 may stop cancer cells from growing.

6. Have any clinical trials (research studies with people) of coenzyme Q10 been conducted?

There have been no well-designed clinical trials involving large numbers of patients to study the use of coenzyme Q10 in cancer treatment. There have been some clinical trials with small numbers of people, but the way the studies were done and the amount of information reported made it unclear if benefits were caused by the coenzyme Q10 or by something else. Most of the trials were not randomized or controlled. Randomized controlled trials give the highest level of evidence:

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