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.
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