History of
Research
Resveratrol is a
naturally occurring phytoalexin that is found in many plants and foods. It is
produced when the plant comes under attack from pathogens such as fungus or
bacteria, and the most significant natural source of resveratrol can be found
in a red wine. It began to receive recognition after a study published by Dr
Sinclair of Harvard found that it extended the lifespan of yeast, fish and
mice. Since these studies were published the focus of some researchers shifted
to resveratrol’s potential to increase human lifespan or healthspan.
Back in 1997, Jang reported that topical resveratrol applications
prevented skin cancer development in mice treated with a carcinogen. There have
since been many studies of the anti-cancer activity of resveratrol in animal
models. However, just recently the scientists started to get positive and
promising results for the cancer prevention in humans.
The strongest evidence of anticancer action of resveratrol exists for
tumors it can contact directly, such as skin and gastrointestinal tract tumors.
For other cancers, it proved to be more complicated to find the substantial evidence
for its positive effects, even in the studies when massive doses of resveratrol
were used.
Thus, resveratrol (1 mg/kg orally) reduced the number and size of
the esophageal tumors in rats treated with a carcinogen; and in several
studies, small doses (0.02–8 mg/kg) of resveratrol, given prophylactically,
reduced or prevented the development of intestinal and colon tumors in rats
given different carcinogens.
While resveratrol treatment appeared to prevent the development of mammary
tumors in animal models no significant effect was found on the growth of
existing tumors
How it Works?
The mechanism of the
cancer prevention by resveratrol is not absolutely clear to the scientists. Resveratrol
is a type of polyphenol called a phytoalexin, a class of compounds produced as
part of a plant's defense system against disease. It is produced in the plant
in response to an invading fungus, stress, injury, infection, or ultraviolet
irradiation.
Resveratrol has been
shown to reduce tumor incidence in animals by affecting one or more stages of
cancer development. It has been shown to inhibit growth of many types of cancer
cells in culture. Evidence also exists that it can reduce inflammation. It also
reduces activation of NF kappa B, a protein produced by the body's immune
system when it is under attack. This protein affects cancer cell growth and metastasis.
Resveratrol is also an antioxidant.
Pancreatic Cancer Prevention
One of the recent
flagman studies on resveratrol from the University of Rochester Medical Center
demonstrated that resveratrol can indeed help counteract the effects of
pancreatic cancer. In tandem with traditional procedures, the antioxidants
helped to boost the immunity system, fighting off free radicals and improving
circulation of healthy blood cells improving recovery time. The drug was said
to be the fighter of mitochondria in cells, which are the carriers of DNA. They
become the source of cellular energy, along with the regulation of a cell’s
life span.
The study also
showed that the resveratrol is very useful for more efficient pancreatic cancer
treatment as it is able to weaken the pancreatic cancer cells and increase
their vulnerability to chemotherapy treatment. Pancreatic cancer is known to be
resistant to chemotherapy due to the fact that the pancreas is always producing
enzymes which are pushed into the duodenum, hence flushing away the
chemotherapy treatment before it has time to combat the disease. The study
found that the pancreatic cancer cells which were treated with resveratrol
affected the cells membranes so that the flushing process was slowed down. This
made the cells more sensitive to chemotherapy treatment and less resistant so
that apoptosis occurred.
Similar results on
the significant positive effect on protection against pancreatic cancer development
were received by the clinical studies at Zhongda Hospital of Southeast
University, Nanjing, Jiangsu, China in 2011.
There are no
practical recommendations yet on how much you should drink red wine or consume
resveratrol from other sources, but one study published in 2006 found that men
who drink four or more glasses of red wine each week were half as likely to
develop prostate cancer compared to men who did not drink red wine. Moderate
red wine consumption of between 1 and 3 glasses a day has also been linked to
lower rates of colon cancer, lung cancer, skin cancer, and coronary heart
disease.
Other Natural Sources of Resveratol
For wine lovers, it
would be good news that the biggest quantities of resveratol were found in
certain brands of red wine. However, for those, who do not consume wine, there
are additional sources as well. First discovered in 1940 in the roots of the
white hellebore plant, reveratrol has since been found in higher concentrations
elsewhere. It is mainly found in 'seed producing' plants like grapes (a vine
plant), yucca, eucalyptus, spruce, lily, blueberries, cranberries, bilberries,
mulberries, peanuts and even chocolate.
In grapes, the skins
are the home of resveratrol, not the seeds or the fruit (though the vine itself
has some resveratrol in it).
Vitis vinifera,
labrusca and muscadine grapes carry the highest concentration of resveratrol,
but ultimately the cultivar, the geographic location and the exposure to fungus
and infection determine the concentration.
Juice and wines made
with red/purple grapes provide the most resveratrol. The amount of resveratrol
red wine and grape juice has is largely dependent on the duration the grape
skins remain in the production process. According to LeRoy Creasy, Professor of
Pomology at Cornell University, grape juice is not only a very consistent
source of resveratrol - but grape juice has more resveratrol than 60% of all
wines. Creasy indicates that red wine vinegar is another source of resveratrol,
but not as concentrated.
Japanese Knotweed
(also known as polygonum cuspidatum) is the major source of the resveratrol in resveratrol
supplements. Japanese Knotweed goes by many other names as well including:
fleeceflower, Himalayan fleece vine, monkeyweed, Hancock's curse, elephant
ears, pea shooters, donkey rhubarb (although it is not a rhubarb), sally
rhubarb, Japanese bamboo, American bamboo, and Mexican bamboo (though it is not
a bamboo). In Japanese, the name is "itadori", and is used in making itadori
tea.
Another strange
source of resveratrol is peanuts. One ounce of peanuts contains approximately
73 micrograms of resveratrol, which is equivalent to almost 2 pounds of grapes.
(A fluid ounce of red wine contains almost twice that).
You may find advertisement
on the resveratrol as natural supplement. Although, while it appears
to be well-absorbed by humans when taken orally, its bio-efficiency is
relatively low due to its rapid metabolism and elimination.
Sources and Additional Information:
