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.
History of Grapes
Description
Grapes are a type of fruit that grow in clusters of 15 to 300, and can be crimson, black, dark blue, yellow, green, orange and pink. "White" grapes are actually green in color, and are evolutionarily derived from the purple grape. Mutations in two regulatory genes of white grapes turn off production of anthocyanins which are responsible for the color of purple grapes. Anthocyanins and other pigment chemicals of the larger family of polyphenols in purple grapes are responsible for the varying shades of purple in red wines. Grapes are typically an ellipsoid shape resembling a prolate spheroid.
The cultivation of the domesticated grape began 6,000-8,000 years ago in the Near East. The earliest archeological evidence for a dominant position of wine-making in human culture dates from 8,000 years ago in Georgia.
Yeast, one of the earliest domesticated microorganisms, occurs naturally on the skins of grapes, leading to the innovation of alcoholic drinks such as wine. The earliest known production occurred around 8,000 years ago on the territory of Georgia.[4] During an extensive gene-mapping project, archaeologists analyzed the heritage of more than 110 modern grape cultivars, and narrowed their origin to a region in Georgia, where wine residues were also discovered on the inner surfaces of 8,000-year-old ceramic storage jars.[5] The oldest winery was found in Armenia, dating to around 4,000 BC. By the 9th century AD the city of Shiraz was known to produce some of the finest wines in the Middle East. Thus it has been proposed that Syrah red wine is named after Shiraz, a city in Persia where the grape was used to make Shirazi wine. Ancient Egyptian hieroglyphics record the cultivation of purple grapes, and history attests to the ancient Greeks, Phoenicians and Romans growing purple grapes for both eating and wine production. The growing of grapes would later spread to other regions in Europe, as well as North Africa, and eventually in North America.
In North America, native grapes belonging to various species of the Vitis genus proliferate in the wild across the continent, and were a part of the diet of many Native Americans, but were considered by European colonists to be unsuitable for wine. Vitis vinifera cultivars were imported for that purpose.
Scientific evidence has proven that grapes have grown wild since at least prehistoric times, and there's human evidence that they were cultivated in Asia in 5000 b.C. There were several references in the bible, with grapes being referred to as "fruits of the vine".
The first reference of wine production was found in ceramic jars in today's Georgia, in what was once a Neolithic village dating back to 6000 b.C. Several other references can be found in Iran, dating back to 5000-5500 b.C. This evidence may suggest that winemaking originated in present-day Georgia and then spread south.
It is very likely that at that time, wine was made from wild grape varieties, and the first references pf domestication of grapes can only be found from 3,200 b.C. onwards, in the Near East.
Wine and Grapes in Roman Times
Several hieroglyphics depict vines in ancient Egypt's burial tombs: winemaking was widely practiced in Egypt in 3000 b.C., and almost all the wine was red, with some notable and rare exceptions.
In Greek and Roman times, grapes were widely known and used to make wines: at the time more than 90 varieties were known, and the Rhine valley (ancient Gallia, modern Germany) was widely covered with grape plantations as early as 100 A.D.
Romans, in particular, developed most of the techniques for winemaking: several provinces began competing with Rome itself for the production of wine, and this led to the development of harvesting techniques, as well as the usage of barrels and bottles and a denomination system to refer to wines grown in different Italian regions.
At the end of the 19th century, archaelogists found a bottle of Roman wine in a sarcophagus in Germany. The bottle dates back to around 327 A.D., and it is topped with what appears to be olive oil: this was a common technique in antiquity, since oil floated on top of the wine and prevented it from evaporating.
Medieval History of Grapes
In medieval times, peasant classes mainly drank ale, while wine was enjoyed by richer classes such as royalty, nobility, priests and merchants. At this time, the main producers of wine were priests, especially the the Benedictines in France and Germany. White wine was as widespread as the red variety, but they were usually drunk young, flavored with spices or honey, and watered down.
Grapes and the American Conquest
During the discovery of Americas, Spanish settlers brought grapes to America, planting them in North America in the early 17th century in what was probably a mission in New Mexico.
Thanks to the Spaniars, grapes rapidly spread to California, where the favorable habitat (perfect climate and absense of predators) made grapes a very successful crop in that zone.
Grapes in Modern Times
In the end of 1800, French production of wine suffered a terrible blow because almost all the wine-producing grape varieties were killed by an insect that found its way to France from North America. This led some botanists to cross-breed French grapes with the American labrusca cultivar, rendering the new hybrid resistant to the insect and preserving the production of wine in France.
For several decades, American wine was considered inferior to European varieties, but in a wine-tasting contest that took place in 1976, in Paris, American wines beat European wines.
With the development of medicine and technology, grapes have been found to possess several health-promoting qualities, which has lead to a large amount of research and increased popularity for this fruit. Nowadays, the largest producers of grapes are Italy, France, Spain, the USA, Mexico and Chile.
Today, as researchers continue to investigate the health-promoting polyphenolic compounds found in grapes, this fruit is gaining even more attention. Currently, Italy, France, Spain, the United States, Mexico and Chile are among the largest commercial producers of grapes.
Seedless grapes
Although grape seeds contain many nutrients, some consumers choose seedless grapes; seedless cultivars now make up the overwhelming majority of table grape plantings. Because grapevines are vegetatively propagated by cuttings, the lack of seeds does not present a problem for reproduction. It is an issue for breeders, who must either use a seeded variety as the female parent or rescue embryos early in development using tissue culture techniques.
There are several sources of the seedlessness trait, and essentially all commercial cultivators get it from one of three sources: Thompson Seedless, Russian Seedless, and Black Monukka, all being cultivars of Vitis vinifera. There are currently more than a dozen varieties of seedless grapes. Several, such as Einset Seedless, Benjamin Gunnels's Prime seedless grapes, Reliance and Venus, have been specifically cultivated for hardiness and quality in the relatively cold climates of northeastern United States and southern Ontario.
An offset to the improved eating quality of seedlessness is the loss of potential health benefits provided by the enriched phytochemical content of grape seeds.
Grapes Juice
Grape juice is obtained from crushing and blending grapes into a liquid. The juice is often sold in stores or fermented and made into wine, brandy or vinegar. In the wine industry, grape juice that contains 7–23 percent of pulp, skins, stems and seeds is often referred to as "must". In North America, the most common grape juice is purple and made from Concord grapes while white grape juice is commonly made from Niagara grapes, both of which are varieties of native American grapes, a different species from European wine grapes. In California, Sultana (known there as Thompson Seedless) grapes are sometimes diverted from the raisin or table market to produce white juice.
Medieval History of Grapes
Scientific evidence has proven that grapes have grown wild since at least prehistoric times, and there's human evidence that they were cultivated in Asia in 5000 b.C. There were several references in the bible, with grapes being referred to as "fruits of the vine".
The first reference of wine production was found in ceramic jars in today's Georgia, in what was once a Neolithic village dating back to 6000 b.C. Several other references can be found in Iran, dating back to 5000-5500 b.C. This evidence may suggest that wine making originated in present-day Georgia and then spread south.
It is very likely that at that time, wine was made from wild grape varieties, and the first references pf domestication of grapes can only be found from 3,200 b.C. onwards, in the Near East.
Wine and Grapes in Roman Times
Several hieroglyphics depict vines in ancient Egypt's burial tombs: wine making was widely practiced in Egypt in 3000 b.C., and almost all the wine was red, with some notable and rare exceptions.
In Greek and Roman times, grapes were widely known and used to make wines: at the time more than 90 varieties were known, and the Rhine valley (ancient Gallia, modern Germany) was widely covered with grape plantations as early as 100 A.D.
Romans, in particular, developed most of the techniques for wine making: several provinces began competing with Rome itself for the production of wine, and this led to the development of harvesting techniques, as well as the usage of barrels and bottles and a denomination system to refer to wines grown in different Italian regions.
At the end of the 19th century, archaeologist found a bottle of Roman wine in a sarcophagus in Germany. The bottle dates back to around 327 A.D., and it is topped with what appears to be olive oil: this was a common technique in antiquity, since oil floated on top of the wine and prevented it from evaporating.
Medieval History of Grapes
In medieval times, peasant classes mainly drank ale, while wine was enjoyed by richer classes such as royalty, nobility, priests and merchants. At this time, the main producers of wine were priests, especially the the Benedictines in France and Germany. White wine was as widespread as the red variety, but they were usually drunk young, flavored with spices or honey, and watered down.
Grapes and the American Conquest
During the discovery of Americas, Spanish settlers brought grapes to America, planting them in North America in the early 17th century in what was probably a mission in New Mexico.
Thanks to the Spaniars, grapes rapidly spread to California, where the favorable habitat (perfect climate and absence of predators) made grapes a very successful crop in that zone.
Grapes in Modern Times
In the end of 1800, French production of wine suffered a terrible blow because almost all the wine-producing grape varieties were killed by an insect that found its way to France from North America. This led some botanists to cross-breed French grapes with the American labrusca cultivar, rendering the new hybrid resistant to the insect and preserving the production of wine in France.
For several decades, American wine was considered inferior to European varieties, but in a wine-tasting contest that took place in 1976, in Paris, American wines beat European wines.
With the development of medicine and technology, grapes have been found to possess several health-promoting qualities, which has lead to a large amount of research and increased popularity for this fruit. Nowadays, the largest producers of grapes are Italy, France, Spain, the USA, Mexico and Chile.
Today, as researchers continue to investigate the health-promoting polyphonic compounds found in grapes, this fruit is gaining even more attention. Currently, Italy, France, Spain, the United States, Mexico and Chile are among the largest commercial producers of grapes.
Health Benefits of Grapes
The bulk of grapes' health benefits comes from their high content in flavonoids and phytonutrients in general: they give the color to grapes, and the more vibrant the color, the higher the content in phytonutrients.
Among these, the most important are quercitin and resveratrol (which is chemically a stilbene), which are responsible, in particular, for the heart-protecting effects: they appear to reduce blood clotting due to an antiaggregant effect on platelets, as well as protecting LDL cholesterol from oxidation (which has been linked to arterial damage).
French Paradox
What is currently known as the "French paradox" consists of the unusually high life expectancy of Frenchmen, if we take into account their diets, exceptionally high in fats. Many nutritionists believe this to be caused by their high consumption of red wine, and in particular the high quantities of antioxidants and flavonoids contained within.
In a study involving 20 healthy volunteers, they had their blood drawn before and after drinking grape juice. After drinking it, their blood contained higher levels of nitric oxide (a compound known to reduce the formation of clots), as well as a decrease in platelet aggregation. A third effect was t e increase of alpha-tocopherol, a member of the antioxidant vitamin E, and general antioxidant levels in blood were found to be 50% higher.
This study confirms what was discovered in a previous study, where an additional effect of drinking grape juice consisted of protecting LDL cholesterol from oxidation: normally, oxidized LDL acts on arteries damaging their walls and increasing the risk of developing atherosclerosis.
It also appears that some phenolic compounds contained in grape skins inhibit protein tyrosine kinases: this is a class of enzymes that regulates cells, inhibiting production of a vessel-constricting hormone (endothelin-1) believed to be a key component in the development of several heart conditions.
The journal Hypertension has published a study showing the way resveratrol inhibits production of endothelin-1 (ET-1): it appears to regulate ET-1 genes, preventing them from being expressed. ET-1 is normally synthesized by endothelial cells when they are damaged by free radicals: resveratrol greatly reduces the formation of free radicals, in turn reducing the expression of the ET-1 genes.
Saponins in Grapes
The American Chemical Society presented research, at its 226th national meeting, showing another explanation for grapes' health benefits: saponins. These phytonutrients appear to lower blood cholesterol, by binding to its molecules and preventing their absorption, as well as reducing inflammation (which may also suggest a cancer-protecting effect). Additionally, the researchers, led by Andrew Waterhouse, PhD, from the University of California, Davis, think that alcohol may improve the bioavailability of saponins, making them more easily absorbed in wine.
Chemically, saponins are glucose-based compounds, in the class of phynutrients, and they're being actively researched and found in several foods such as soybeans and olives: Waterhouse also tested six California grape cultivars (two white and four red) for their saponin content.
He proved that red wines contain 3 to 10 times the amount of saponins contained in white wines, as well as showing a positive correlation between alcoholic concentration and saponin concentration (stronger wines had more saponins), with red Zinfandel (16% alcohol) containing the highest levels. In order of saponins, Syrah was second, followed by Pinot noir and Cabernet Sauvignon, wihle the white varieties (Sauvignon blanc and Chardonnay) contained much less.
Quoting Waterhouse: Average dietary saponin intake has been estimated at 15 mg, while one glass of red wine has a total saponin concentration of about half that, making red wine a significant dietary source
Pterostilbene
Grapes also contain another antioxidant compound called Pterostilbene, known for its cancer-fighting and cholesterol-lowering properties.
In a study carried out by the USDA Agricultural Research Service on animal liver cells, pterostilbene was tested versus ciprofibrate (a drug that lowers blood lipids) and resveratrol for its cholesterol-lowering effects.
The comparison was based on these compounds' ability to activate PPAR-alpha, which is a family of cell membrane receptors involved in the transport of several energy-related compounds (including cholesterol) in and out of the cell.
As it turned out, the effects of Pterostilbene were higher than resveratrol, and on par with ciprofibrate in activating PPAR-alpha. Pterostilbene can not only be found in grapes, but also in blueberries and cranberries.
Polyphenols and effects in Women
A study, published in the Journal of Nutrition, was carried out by having 24 pre and 20 post-menopausal women drink a glass of water with 36g of freeze-dried grape powder, every day, for 4 weeks.
After this period, several cardiovascular benefits could be demonstrated, including:
Lower blood levels of LDL cholesterol and apolipoproteins class B and E (they are involved in the formation of atheromas, precursors of clots in atherosclerosis)
Lower triglyceride levels, by 15% and 6% in pre and postmenopausal women (respectively)
15% lower activity of Cholesterol ester transfer protein (inhibiting this protein has been shown to increase HDL levels, decreasing LDL at the same time)
Significant lower blood levels of urinary F(2)-isoprostanes (a marker of damage cause by free radicals) and TNF-alpha (a major component the inflammatory process)
These protective effects can be explained by the presence of several important antioxidants in grapes, including kaempferol, resveratrol, myriceting, quercetin, flavans and anthocyanins.
Effects of Wine on Hypertension
It has been suggested by several studies that drinking 1 to 2 glasses of red wine per day significantly lowers your risk of hypertension. According to research published in the American Journal of Clinical Nutrition, this is caused by the presence of important antioxidant polyphenols and phytonutrients, but also by the usage of moderate quantities of ethanol (alcohol) that causes a slight vasodilation.
Resveratrol Health Benefits
Resveratrol and your Heart
Research published by Northeastern Ohio Universities College of Medicine in the American Journal of Physiology, and carried out by a team of researchers led by Gary Meszaros and Joshua Bomser, showed that resveratrol inhibits production of endothelin-1 and it directly affects hearth cells by inhibiting antiotensin II, one of the most powerful vasocontricting hormones in our body.
This hormone is physiologically released by the renin-angiontensin-aldosterone pathway, in response to low blood pressure, and has the effect of increasing blood pressure: in people with hypertension, this causes the heart muscle to undergo hyperplasia, producing more fibroblasts and collagen, which cause the myocardium to stiffen and become more bulky, hindering its pumping activity.
Another effect of resveratrol is the prevention of differentiation of fibroblasts into myofibroblasts, which produce lots of collagen.
Cancer Prevention Properties of Resveratrol
While several studies have been carried out on the cancer-preventing action of resveratrol, one of the best was published in the Journal of Applied Toxicology.
Resveratrol Molecule
This study shows how resveratrol protects against benzopyrene (the main carcinogen found in cigarette smoke, and one of the prime causes of lung cancer). Resveratrol apparently blocks a cell receptor (aryl hydrocarbon receptor or AhR) that benzopyrene and several other carcinogenic polycyclic aromatic hydrocarbons use to bind to cell membranes. Their binding to AhR causes the expression of several cancer-promoting genes.
This study showed how animals exposed to high levels of benzopyrene underwent significant DNA damage, but the damage was cut in half when they were also given resveratrol. In addition, resveratrol promoted apoptosis (induced cell death) in cancerous cells, which causes cancerous cells to die before having a chance to replicate and become a large tumor.
Other independent studies also suggest a protective effect against liver and breast cancer cells.
Resveratrol and Lung Health
Professor Juan Barros-Dios and his team at the University of Santiago de Compostela, Spain, published a study carried out on hospital case-controls. A daily glass of white wine provided 20% higher risks of lung cancer, while red wine lowered the risk by 13%, with no effect being linked to consumption of beer and spirits.
It has been hypothesised that the different in effects between red and white wine is linked to red wine's higher concentrations of resveratrol: another study published in the American Journal of Physiology: Lung, Cellular and Molecular Physiology has shown, in fact, that resveratrol can provide a potent anti-inflammatory effect on the cells found in nasal and airway mucosas, blocking several inflammatory molecules, including NF-kB, inducibile nitric oxide synthase and IL-8. It is noteworthy that for NF-kB, resveratrol had a higher inhibiting effect that a commonly used, potent glucocorticoid drug, dexamethasone.
Another effect of resveratrol is inhibition of the production of Cyclooxigenase-2 (COX-2) in airway mucosas: this compound is pro-inflammatory, and is commonly inhibited with drugs like Vioxx and Celebrex. These drugs are being removed from the market due to their tendency of increasing risks of cardiovascular disease, but resveratrol has no such effects, making it a better alternative.
Quoting the researchers: This study demonstrates that resveratrol and quercetin have novel nonsteroidal anti-inflammatory activity that may have applications for the treatment of inflammatory diseases. Louise Donnelly, the lead researcher in the study, has begun investigating resveratrol use in an aerosol spray to treat chronic obstructive pulmonary disease and asthma.
Catechins and Epicatechins
Lawrence M. Szewczuk and Trevor M. Penning from the University of Pennsylvania, have pointed out in a study published in the Journal of Natural Products that not only resveratrol is responsible for the health benefits of red wines: other nutrients found in far greater amounts in grapes as well as red wine, catechins and epicatechins, might be due the most credit!
Much of the health promoting effects of resveratrol are carried out by its modifying effect on the activity of cyclooxygenase (both COX-1 and COX-2 have been studied extensively by pharmaceutical companies, in order to develop new drugs with fewer digestive side-effects.
In particular, Resveratrol blocks COX-2 activity through changes in another system of messaging molecules called NF-kappaB and I-kappaB kinase (indirectly), while COX-1 is blocked directly. Catechins and epicatechins, which are present in much greater amounts in grapes as well as red wine, have been proven to have a higher potency in reducing activity of COX-1 and COX-2, in much smaller amounts than resveratrol.
Anti-Aging effect of Resveratrol
It is widely known that the events that lead to cancer are also the same that lead to aging (referring specifically to cell DNA damage).
In a recently published study, resveratrol has been proven to activate Sir2, and enzyme that has been shown to be the cause for increased lifespan in animals places on calorie-restricted diets.
Several studies were carried out on Saccharomyces cerevisiae (the common yeast): its life was extended through calorie restriction, with a biochemical pathway involving Sir2, and it's been proven that overproduction of this enzyme can longer the lifespan of yeast grown with a normal caloric intake. The same results have been observed in the more biologically advanced worm Caenorhabditis elegans.
Sir2 is an enzyme of the family of sirtuins: these enzymes are found in all life forms, including mammals, since they are necessary for the regulation of cell differentiation and death.
Knowing that Sir2 was the main compound responsible for prolonged lifespans in calorie-restricted animals, Howitz et al. wanted to find a molecule that could activate the enzyme directly: they found two molecules, both belonging to plant polyphenols, of which resveratrol was by far the most potent. Resveratrol increased lifespan in yeast by 70%, and the effect was totally related to the increased activation of Sir2 (in fact, yeast lacking the Sir2 enzyme and given resveratrol did not benefit from a prolonged lifespan).
But what about humans? Resveratrol has been found to stimulate sirtuin activity at low doses, but it had the opposite effect at high doses. However, due to the extremely low concentration of resveratrol in food, it is unlikely for a person to ingest too much. Drinking several glasses of grape juice will only yield low doses, and might be just perfect to benefit from resveratrol's health benefits.
Resveratrol as an Anti-Microbial Agent
Research carried out in Turkey, at Erciyes University, found that an extract made from grape seeds, skin and stems had a potent anti-microbial efect against 14 bacteria, including the common Escherichia coli and Staphylococcus aureus. The extract had bacteriostatic properties against all bacteria at concentrations of 2.5, 5, 10 and 20%. The only bacterium that was uninhibited was Yersinia enterocolica, and only at a concentration of 2.5%
