- What is Coenzyme Q10?
Coenzyme Q10 (also known as CoQ10,
Q10, vitamin Q10, ubiquinone, or
ubidecarenone) is a compound that is made naturally in the body. A
coenzyme is a substance needed for the proper functioning of an
enzyme, a
protein that speeds up the rate at which chemical reactions
take place in the body. The Q and the 10 in coenzyme Q10
refer to parts of the compound’s chemical structure.
Coenzyme Q10 is used by
cells to produce energy needed for cell growth and maintenance.
It is also used by the body as an
antioxidant. An antioxidant is a substance that protects cells
from chemicals called free radicals.
Free radicals are highly reactive chemicals that can damage
important parts of cells, including
deoxyribonucleic acid (DNA).
(DNA is a
molecule inside cells that carries
genetic information and passes it from one generation to the
next.) This damage may play a role in the development of 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. Tissue levels of coenzyme Q10 decrease as
people get older.
- 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 potential treatment for
cancer began in 1961, when a deficiency of the enzyme was noted in
the
blood of cancer patients.
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 have yielded information about how coenzyme Q10
works in the body to produce energy and act as an antioxidant.
Some studies have suggested that coenzyme Q10
stimulates the
immune system and increases
resistance to disease. In part because of this,
researchers have theorized that coenzyme Q10 may be
useful as an
adjuvant therapy for cancer. (Adjuvant therapy is treatment
given following the primary treatment to enhance the effectiveness
of the primary treatment.)
Researchers have
theorized that coenzyme Q10 may be useful as an
adjuvant therapy for cancer
(HealthWorks
2000 CoQ10 Recommendation)
- 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.
- Have any preclinical (laboratory and
animal) studies been conducted using coenzyme Q10?
Laboratory studies of coenzyme Q10
have focused on describing its chemical structure and how it works
in the body. Animal studies have found that coenzyme Q10
stimulated the immune system and increased resistance to disease.
Coenzyme Q10 helped to protect the hearts of animals
given the anticancer drug
doxorubicin, which can cause damage to the heart muscle.
Coenzyme Q10 helped to protect the hearts of animals
given the anticancer drug
doxorubicin, which can cause damage to the heart muscle.
(HealthWorks
2000 CoQ10 Recommendation)
- Have any
clinical trials (research studies in humans) been conducted
with coenzyme Q10?
The promising results from animal studies
of coenzyme Q10 and the anticancer drug doxorubicin led
researchers to test coenzyme Q10 in a
randomized clinical trial with 20 patients. (A
randomized
clinical trial is a study in which the participants are
assigned by chance to separate groups that compare different
treatments; neither the researchers nor the participants can
choose which group.) The researchers examined whether
coenzyme Q10
would protect the heart from the damage caused by doxorubicin. The
results of this trial and others have confirmed that coenzyme Q10
decreases the effects of doxorubicin on the heart. However, no
report of a randomized clinical trial of coenzyme Q10
as a treatment for cancer has been published in a peer-reviewed,
scientific journal.
- Have other studies of coenzyme Q10
been conducted in people?
Three other small studies were conducted
using coenzyme Q10 as a dietary supplement in patients
undergoing conventional cancer treatment. In these studies, the
researchers explored the potential use of coenzyme Q10
as an adjuvant therapy for cancer.
 | The first study, which was conducted
in Denmark, involved 32 breast cancer patients. All of the
participants received coenzyme Q10 and several
other dietary supplements, in addition to their standard
treatment. Six of the patients were reported to show some
signs of
remission (disappearance of the signs and symptoms of
cancer). However, the data were not complete, and information
that suggested remission was presented for only three of the
six patients. All of the participants reported decreased use
of painkillers, improved
quality of life, and absence of weight loss during
treatment.
|
| In a followup study, one new patient
and one of the patients who had a reported remission were
treated with high
doses of coenzyme Q10 for 3 to 4 months. Both
of the patients had breast cancer remaining after
surgery. After the period of high-dose coenzyme Q10
supplementation, both patients appeared to experience
complete
regression (decrease in the size or extent) of their
remaining cancer. However, it is not known which of the six
patients with a reported remission in the first study took
part in the followup study.
|
| In a third study conducted by the
same researchers, three breast cancer patients were given
high-dose coenzyme Q10 and followed for 3 to 5
years. One patient had
complete remission of cancer that had spread to the liver,
another had remission of cancer that had spread to the chest
wall, and the third had no evidence of breast cancer remaining
after surgery. |
The first study,
which was conducted in Denmark, involved 32 breast cancer patients....The
first study, which was conducted in Denmark, involved 32 breast
cancer patients
After the period
of high-dose coenzyme Q10
supplementation, both patients appeared to experience
complete
regression (decrease in the size or extent) of their
remaining cancer
One patient had
complete remission of cancer that had spread to the liver,
another had remission of cancer that had spread to the chest wall,
and the third had no evidence of breast cancer remaining after
surgery
(HealthWorks
2000 CoQ10 Recommendation)
It is important to note that problems with
the design of these studies may have influenced their results. For
example, the studies did not have
control groups (all patients received coenzyme Q10),
and there may have been differences in the characteristics of
patients who were selected for the follow
up study and those who
were not. Other factors that may have affected the results include
the following: the participants received a variety of supplements
in addition to coenzyme Q10, and they received standard
treatment either during or just before coenzyme Q10
supplementation. Therefore, it is impossible to determine whether
any of the beneficial results was directly related to coenzyme Q10
therapy.
There have also been
anecdotal reports that coenzyme Q10 has increased
the survival of patients with cancers of the pancreas, lung,
colon,
rectum, and prostate. (Anecdotal reports are incomplete
descriptions of the medical and treatment history of one or more
patients.) The patients described in these reports also received
treatments other than coenzyme Q10, including
chemotherapy,
radiation therapy, and surgery.
Coenzyme
Q10 has increased
the survival of patients with cancers of the pancreas, lung,
colon,
rectum, and prostate.
(HealthWorks
2000 CoQ10 Recommendation)
- Have any side effects or risks been
reported from coenzyme Q10?
No serious side effects have been reported
from the use of coenzyme Q10. Some patients using
coenzyme Q10 have experienced mild
insomnia (inability to sleep), elevated levels of liver
enzymes, rashes, nausea, and upper
abdominal pain. Other reported side effects have included
dizziness, visual sensitivity to light, irritability, headache,
heartburn, and fatigue.
Patients should talk with their health
care provider about possible interactions between coenzyme Q10
and
prescription drugs they may be taking. Certain drugs, such as
those that are used to lower cholesterol or blood sugar levels,
may reduce the effects of coenzyme Q10. Coenzyme Q10
may also alter the body’s
response to
warfarin (a drug that prevents the blood from clotting) and
insulin.
- Are there any other potential drawbacks
to taking coenzyme Q10?
As noted in question 1, coenzyme Q10
is used by the body as an antioxidant. Antioxidants protect cells
from free radicals, which are highly reactive chemicals that can
damage cells. Some conventional cancer therapies, such as
anticancer drugs and
radiation treatment, kill cancer cells in part by causing free
radicals to form. Researchers are studying whether using coenzyme
Q10 along with conventional therapies is positive
(i.e., does not interfere with the effects of the conventional
therapies, or increases the therapies’ beneficial effects on
cancer cells while protecting normal cells) or negative (i.e.,
interferes with the therapeutic effects).
- Has the Food and Drug Administration
(FDA) approved coenzyme Q10 for use in the United
States?
Several companies distribute coenzyme Q10
as a dietary supplement. In the United States, dietary supplements
are regulated as foods, not drugs. This means that evaluation and
approval by the FDA are not required before marketing, unless
specific health claims are made about the supplement. It should be
noted that, because dietary supplements are not formally reviewed
for manufacturing consistency, there may be variation in the
composition of the supplement from one batch to another.
Also, to conduct clinical drug research
with humans in the United States, researchers must file an
Investigational New Drug (IND) application with the FDA.
Because an IND application is highly confidential, it is not known
whether one has been submitted or approved for the study of
coenzyme Q10 as a treatment for cancer.
- When considering complementary and
alternative therapies, what questions should patients ask their
health care provider?
| What benefits can be expected from this
therapy? |
| What are the risks associated with this
therapy? |
| Do the known benefits outweigh the
risks? |
| What side effects can be expected?
|
| Will the therapy interfere with
conventional treatment? |
| Is this therapy part of a clinical
trial? If so, who is sponsoring the trial? |
| Will the therapy be covered by health
insurance?
|
- How are complementary and alternative
approaches evaluated?
It is important that the same scientific
evaluation which is used to assess conventional approaches be used
to evaluate complementary and alternative therapies. A number of
medical centers are evaluating complementary and alternative
therapies by developing clinical trials to test them.
More information about how CAM approaches
are evaluated can be found in the
National Cancer Institute (NCI)
fact sheet Complementary and Alternative Medicine in Cancer
Treatment: Questions and Answers. This fact sheet can be
accessed at
http://cis.nci.nih.gov/fact/9_14.htm on the Internet, or by
calling the
Cancer Information Service (CIS)
at 1–800–422–6237.
- How can patients and their health care
providers learn more about complementary and alternative
therapies?
Patients and their doctor or nurse can
learn about complementary and alternative therapies from the
following Government agencies:
The National Center for Complementary
and
Alternative Medicine (NCCAM) at the
National Institutes of Health (NIH)
facilitates research and evaluation of complementary and
alternative practices, and provides information about a variety
of approaches to health professionals and the public.
Therapeutic
Dosage
