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Other common
name(s): grape diet, grape cure, grape seed extract (GSE),
grape seed proanthocyanidin extract (GSPE), grape seed oil, grape
skins, proanthocyanidins, oligomeric proanthocyanidins (OPCs),
resveratrol
Scientific/medical
name(s): Vitis
vinifera, Vitis
coignetiae
Description
Grapes grow wild on vines or are cultivated. They are believed
to be native to northwest Asia although they have been grown throughout
Europe and the United States for centuries. The seeds, skin, leaves,
stems, and grape itself are used in herbal remedies. At times in the
past, diets consisting solely of grapes have been touted as an
alternative means of treating cancer. Some chemicals found in grape
extract (called proanthocyanidins) and in grape skins (called
resveratrol) are currently being studied for possible uses in the
prevention and treatment of cancer and other illnesses.
Overview
Available scientific evidence does not support claims that a
diet of grapes alone is effective for treating cancer or any other
disease. Some laboratory evidence suggests that certain chemicals in
grapes and their seeds and skins may help prevent heart disease and
cancer, but more research is needed in people to understand the
possible long-term benefits.
How is it promoted for use?
Alternative practitioners recommend the use of grapes and
parts of the grape plant for high blood pressure, menopause, varicose
veins, high cholesterol, skin rashes, and urination problems. They also
claim it works for inflammation of the gums, throat, eyes, and mouth.
Although used rarely today, the grape diet (see below) was promoted at
different times in the twentieth century as a treatment to flush toxins
from the body and protect the body against cancer and virtually all
other diseases. Some supporters believed that the diet cured cancer.
Evidence suggests that proanthocyanidins,the chemical found in
grape seed extract are powerful antioxidants. Antioxidants are
compounds that block the action of free radicals, activated oxygen
molecules that can damage cells. Proponents claim that these
antioxidants inhibit the development of some types of cancer, protect
against heart disease, and are useful for treating a variety of medical
conditions such as arthritis, allergies, circulatory problems,
diabetes, water retention, and vision problems.
A compound called resveratrol, which is found in the skins of
red grapes is being studied to see how it affects the development and
progression of heart disease and cancer.
What does it involve?
Fresh, preserved, and dried grapes are used as is or in the
form of liquid extracts, tinctures, gargles, enemas, douches, and
compresses. Grape skins are also used in making red wine. Grape seed
extract and resveratrol are available as dietary supplements in tablet
and capsule form. The amount of these substances in different
supplements varies by manufacturer.
The complete grape diet begins with fasting and daily enemas
for a few days and is followed by a diet of grapes and water for one to
2 weeks. Then, fresh fruits and sour milk can also be consumed. The
next stage of the diet includes raw vegetables, salads, nuts, dairy
products, honey, and olive oil. During the final stage of the diet, if
a person is doing well, he or she may be allowed to add one cooked meal
per day.
What is the history behind it?
Grapes have been associated with health for many centuries.
Evidence of fossilized grape leaves, stems, and seeds dating back 10 to
12 million years ago has been found in the Northern hemisphere. Grapes
from the Vitis vinifera
species were grown for thousands of years in the Old World before they
were brought to the United States.
Johanna Brandt, a South African dietitian, proposed the grape
diet in 1925. Brandt claimed to have cured herself of stomach cancer by
following the diet. After immigrating to the United States in 1927, she
opened the Harmony Healing Centre in New York City and began promoting
the treatment. She wrote a book that was first published in 1928 and
was republished several times throughout the 20th century. Because no
scientific evidence supported their claims that the treatment improved
health or cured disease, Brandt and some of her followers who
prescribed or promoted the grape diet as a cure for cancer eventually
became the targets of intense criticism and even legal action.
During the past few decades, interest in understanding the
role of antioxidants in health has begun to grow. Proanthocyanidins
were extracted from grape seeds in 1970. In the mid-1990s, a compound
called resveratrol, found mostly in the skins of red grapes, was first
suggested to be responsible for the "French paradox," the low
occurrence of heart disease among the French, who tend to eat a
high-fat diet.
What is the evidence?
While some substances in grapes may hold promise against
cancer, there is very little reliable scientific evidence available at
this time that drinking red wine, eating grapes, or following the grape
diet can prevent or treat cancer in people.
Several laboratory studies in cell cultures have shown that
proanthocyanidins, the chemicals found in grape seed extract, have
antioxidant properties. A small randomized clinical trial of grape seed
extract in healthy volunteers supported this finding. Some laboratory
studies have also found that proanthocyanidins may reduce the
body’s production of estrogen, which could possibly affect
hormone-sensitive tumors such as some types of breast cancer. It is not
yet clear whether these properties will translate into anticancer
benefits in people. Early clinical trials are currently in progress to
find the best dose of grape seed extract for suppressing estrogen
levels for breast cancer prevention.
Studies in laboratory animals have suggested that grape seed
extract may act against prostate, colon, and breast cancer. One
laboratory study found that grape seed extract seemed to make the
chemotherapy drug doxorubicin more effective against breast cancer
cells. Randomized clinical trials are needed to determine whether grape
seed extract can be helpful in cancer treatment.
Laboratory and animal studies have shown that resveratrol may
help prevent heart disease and cancer. It appears to have antioxidant,
anti-inflammatory, and possibly antiestrogenic properties. It also
seems to activate liver enzymes that are responsible for ridding the
body of unwanted chemicals. These properties may mean it will be active
against cancer in people, but randomized clinical trials are needed to
confirm this. Early clinical trials are now under way in healthy
volunteers to determine the amount of resveratrol that can be given
safely. This dose will then be used in studies of resveratrol for
cancer prevention. Note, however, that a study of extracted chemicals
would not be expected to have the same result as a study using the raw
plant.
Some population-based studies have found that people who drink
red wine may have lower incidences of lung and prostate cancer. As
always in these types of studies, many other factors could account for
the difference in cancer risk. In addition, several studies have found
that high intake of alcohol, regardless of the type, is linked to an
increase in breast cancer and some other types of cancer.
While the early research on some substances in grapes is
promising, it is very hard to determine the exact role a particular
food may have against cancer. A balanced diet that includes 5 or more
servings a day of fruits and vegetables along with foods from a variety
of other plant sources such as nuts, seeds, whole grain cereals, and
beans is likely to be more effective than eating one particular food in
large amounts.
Are there any possible problems or
complications?
This product is sold as a
dietary supplement in the United States. Unlike drugs (which must be
tested before being allowed to be sold), the companies that make
supplements are not required to prove to the Food and Drug
Administration that their supplements are safe or effective, as long as
they don't claim the supplements can prevent, treat, or cure any
specific disease.
Some such products may not
contain the amount of the herb or substance that is written on the
label, and some may include other substances (contaminants). Actual
amounts per dose may vary between brands or even between different
batches of the same brand.
Most such
supplements have not been tested to find out if they interact with
medicines, foods, or other herbs and supplements. Even though some
reports of interactions and harmful effects may be published, full
studies of interactions and effects are not often available. Because of
these limitations, any information on ill effects and interactions
below should be considered incomplete.
An exclusive grape diet is unhealthy and does not supply the
body with adequate amounts of protein and important nutrients. Grape
seed extract is believed to be safe, but additional research is needed
for confirmation.
The amount of resveratrol in red wine varies greatly, and
increased consumption of wine to raise resveratrol intake may pose
certain health risks. Alcohol is linked with a higher risk of cancer of
the mouth, esophagus, pharynx, larynx, and liver in both men and women,
and a higher risk of breast cancer in women. Cancer risk also increases
with the amount of alcohol consumed. However, the cardiovascular
benefits of moderate drinking (2 drinks a day for men, 1 drink a day
for women) may outweigh the risk of cancer in men over age 50 and in
women over age 60.
Some substances in grapes may affect how quickly enzymes in
the body get rid of certain chemicals, which could possibly affect the
blood levels of certain drugs. If you are thinking about taking a
grape-derived supplement, talk to your doctor.
The possible effects on pregnancy or breast-feeding have not
been well studied. Relying on this treatment alone and avoiding or
delaying conventional medical care for cancer, may have serious health
consequences.
Additional Resources
More information from your American Cancer
Society
The following information on complementary and alternative
therapies may also be helpful to you. These materials may be found on
our Web site (www.cancer.org)
or ordered from our toll-free number (1-800-ACS-2345).
References
American Cancer Society. Unproven methods of cancer
management. Grape diet.
CA Cancer J Clin. 1974;24:144-146.
Athar M, Back JH, Tang X, Kim KH, Kopelovich L, Bickers DR,
Kim AL. Resveratrol: a review of preclinical studies for human cancer
prevention. Toxicol
Appl Pharmacol. 2007;224:274-283.
Barrett S. The Grape Cure. 2001. Accessed at:
http://www.quackwatch.org/01QuackeryRelatedTopics/Cancer/grape.html on
June 10, 2008.
Eng ET, Ye J, Williams D, Phung S, Moore RE, Young MK, et al.
Suppression of estrogen biosynthesis by procyanidin dimers in red wine
and grape seeds. Cancer
Res. 2003;63: 8516-8522.
Kaur M, Singh RP, Gu M, Agarwal R, Agarwal C. Grape seed
extract inhibits in vitro and in vivo growth of human colorectal
carcinoma cells. Clinical
Cancer Research. 2006; 12:6194-202.
Kijima I, Phung S, Hur G, Kwok SL, Chen S. Grape seed extract
is an aromatase inhibitor and a suppressor of aromatase expression. Cancer Research.
2006;66:5960-5967.
Kim H, Hall P, Smith M, Kirk M, Prasain JK, Barnes S, Grubbs
C. Chemoprevention by grape seed extract and genistein in
carcinogen-induced mammary cancer in rats is diet dependent. J Nutr.
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Kushi LH, Byers T, Doyle C, Bandera EV, McCullough M,
McTiernan A, Gansler T, Andrews KS, Thun MJ, American Cancer Society
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American Cancer Society guidelines on Nutrition and Physical Activity
for cancer prevention: reducing the risk of cancer with healthy food
choices and physical activity. CA
Cancer J Clin 2006;56:254-281.
Memorial Sloan-Kettering Cancer Center. About herbs: Grape
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June 10, 2008.
Mitchell SH, Zhu W, Young CY. Resveratrol inhibits the
expression and function of the androgen receptor in LNCaP prostate
cancer cells. Cancer Res.
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Mantena SK, Baliga MS, Katiyar SK. Grape seed
proanthocyanidins induce apoptosis and inhibit metastasis of highly
metastatic breast carcinoma cells. Carcinogenesis.
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Mohan J, Gandhi AA, Bhavya BC, et al. Caspase-2 triggers
Bax-Bak-dependent and -independent cell death in colon cancer cells
treated with resveratrol. Journal
of Biological Chemistry. 2006; 281:17599-17611.
Moss RW. Herbs
Against Cancer. New York, NY: Equinox Press; 1998.
National Institutes for Health. IH636 Grape Seed Extract in
Preventing Breast Cancer in Postmenopausal Women at Risk of Developing
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on June 10, 2008.
Nuttall SL, Kendall MJ, Bombardelli E, Morazzoni P. An
evaluation of the antioxidant activity of a standardized grape seed
extract, Leucoselect. J
Clin Pharm Ther. 1998;23:385-389.
PDRhealth. Grape seed proanthocyanidins. Accessed at:
www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/gra_0129.shtml
on June 10, 2008.
PDRhealth. Resveratrol. Accessed at:
www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/res_0224.shtml
on June 10, 2008.
Ruano-Ravina A, Figueiras A, Barros-Dios JM. Type of wine and
risk of lung cancer: A case-control study in Spain. Thorax.
2004;59:981-985.
Sharma G, Tyagi AK, Singh RP, Chan DC, Agarwal R. Synergistic
anti-cancer effects of grape seed extract and conventional cytotoxic
agent doxorubicin against human breast carcinoma cells. Breast Cancer Res Treat.
2004;85:1-12.
Veluri R, Singh RP, Liu Z, Thompson JA, Agarwal R, Agarwal C.
Fractionation of grape seed extract and identification of gallic acid
as one of the major active constituents causing growth inhibition and
apoptotic death of DU145 human prostate carcinoma cells. Carcinogenesis.
2006; 27:1445-1453.
Note: This information may not cover
all possible claims, uses, actions, precautions, side effects or
interactions. It is not intended as medical advice, and should not be
relied upon as a substitute for consultation with your doctor, who is
familiar with your medical situation.
Last Medical Review: 11/01/2008
Last Revised: 11/01/2008
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