In recent years, scientists have been interested in a plant-based molecule called resveratrol. Found in the skins and seeds of dark-colored fruits, and in peanuts, resveratrol is especially noticeable in red-skinned and purple-skinned grapes, and in the red wine made from those grapes.
Many diseases associated with aging are thought to be caused by oxidation of free radicals in the body, which ultimately causes cell death. Science is seeking new plant sources of antioxidants to fight such diseases as coronary heart disease, cancer, neurodegenerative diseases, obesity, diabetes, and others. Resveratrol appears to be among the most promising such sources.
Numerous studies, both in test tubes and with animals, have supported the therapeutic potential of resveratrol in coronary heart disease. Researchers are also discovering that resveratrol also appears to be a strong candidate for cancer chemoprotection. Studies on breast cancer, skin cancer, pancreatic cancer, and prostate cancer have all provided evidence of such chemoprotection.
Another promising area of resveratrol study is its ability to activate the sirtuins, a class of proteins found in many organisms from bacteria to humans. Sirtuins link nutrients and energy metabolism. Dietary calorie restriction activates sirtuin; and calorie restriction has been shown to increase lifespan and benefit age-related diseases. Thus, research is focusing on the development of chemicals that are sirtuin activators – like resveratrol.
The SIRT1 gene that is activated by resveratrol is not only a “longevity gene,” but also a powerful fat burner. Since resveratrol increases metabolic activity and physical stamina, it has potential for enabling overweight and obese individuals to perform more, and more strenuous, exercise. Resveratrol has therefore been taken up by many companies that advertise weight loss products. However, these products are of widely-varying quality, and the consumer should be careful when choosing among them.
With regard to neurodegenerative diseases like Alzheimer’s disease, ongoing research strongly supports resveratrol’s potential ability to slow or stop disease progression. It also may lead to the development of powerful synthetic analogs of resveratrol that may enable us, in the near future, to reverse the symptoms of Alzheimer’s, and other diseases such as Parkinson’s disease and Huntington’s disease.
Resveratrol is widely available from drugstores and the Internet in the form of supplements. As with the weight loss products mentioned above, it is wise to keep several points in mind when you shop for resveratrol supplements. Look for the letters “NSF GMP” on the label, to ensure that the supplements are manufactured to the standard of the National Sanitation Foundation. Also, be sure the label specifically indicates trans-resveratrol in the supplements. This is the more active, un-degraded isomer of the resveratrol molecule, and the only one that provides any health benefits.
Some recent research has suggested that another polyphenol, quercetin, may enhance resveratrol’s performance. Significant quantities of both quercetin and resveratrol are present in red wine. Some studies indicate that quercetin increases the bioavailability of resveratrol, making it more easily absorbed by the body. Other studies focus on the fact that quercetin and resveratrol, given together, suppressed the formation of fat cells and induced programmed cell death in mature fat cells better than either compound did alone.
Alone or in combination with other plant chemicals, resveratrol continues to be the focus of a great deal of ongoing research. It seems probable that resveratrol will play a significant part in the future, both in preventing and in treating the diseases of aging.
During the past twenty years or so, the scientific community has paid increasing attention to a plant-based molecule called resveratrol. The function of resveratrol in plants is to act as an antifungal agent, especially in crops that have not been treated with man-made fungicides. In laboratory studies, however, the antioxidant properties of resveratrol have been of greater interest to scientists.
Research has determined that many diseases of aging may be caused by oxidative damage from free radicals. These unstable molecules can damage parts of cells (for example, DNA or lipids), ultimately causing cell death. Since the body’s natural antioxidant mechanism becomes less effective as we grow older, science has sought new plant sources of antioxidants to help fight these diseases. Resveratrol seems to be the most promising of these.
Resveratrol has been found in the skins and seeds of dark-colored fruits like blueberries, cranberries, strawberries, and pomegranates, as well as in peanuts. Especially rich in resveratrol are red-skinned and purple-skinned grapes. It is because of the presence of resveratrol in the skin of red grapes that the compound has become popularly known as a “red wine ingredient”. The production of red wine requires that the skins of the grapes soak in the juice as it ferments; whereas in the production of white wine, the skins are removed. The longer the skins soak in the liquid, the darker the color of the wine will be. Because fungal infections of grapes are more common in cooler climates, it follows that greater amounts of resveratrol will be found in the skins of grapes grown in cooler climates.
Since it appears that resveratrol may be the main bioactive compound in red wine, scientists have begun to associate it with the “French Paradox.” This term comes from an article written in 1992 by Dr. Serge Renaud from the University of Bordeaux. Renaud speculated on why the French, with their high-fat diet (lots of cheese, liver paté, and cream) and daily levels of wine consumption, nevertheless have a relatively low occurrence of both obesity and heart disease. The apparent cardioprotective property of red wine has been discussed in such popular magazines as Fortune (February 23, 2007) and Discover (September 16, 2008), as well as in scholarly journals such as Journal of Medicinal Food (June 2009). CBS News, in a “60 Minutes” presentation in January 2009, speculated whether resveratrol might turn out to be the long-sought “fountain of youth”. And study after study is being carried out on resveratrol to find out as much as possible about its potential protection against heart disease.
Several recent studies have investigated resveratrol’s ability to provide protection against neurodegenerative diseases by counteracting the effects of oxidation. One example is discussed in a review in the September 2009 issue of Alcoholism: Clinical & Experimental Research of a study from the University of Queensland, Brisbane, Australia. According to associate professor Lindsay Brown, corresponding author for the study, “resveratrol turns on the cell’s own survival pathways, preventing damage to individual cells (and) removing very reactive oxidants in the body.”
In the following sections, we will discuss briefly the latest findings on resveratrol and its effects on heart disease, cancer, the aging process, Alzheimer’s disease, and obesity. We will also discuss research on resveratrol supplements, their effectiveness, and how to be sure your resveratrol supplements are of the highest quality. Finally, we will discuss the way another polyphenol called quercetin can work in synergy with resveratrol to improve its performance.
Throughout the 20th century and into the 21st century as well, coronary heart disease (CHD) has been among the top five causes of death for Americans. CHD is a narrowing of the arteries or blood vessels supplying oxygen and blood to the heart. Its immediate cause is usually atherosclerosis, or the build-up of plaque on the inner walls of the arteries. From the 1920s onward, as our lifestyle became more sedentary and our diet more crammed with fats and sugars, heart disease took – and held – first place in the competition. Currently, coronary heart disease affects more than 14 million people in the United States, and its mortality rate is very high: CHD kills more people than the next seven causes of death combined.
The so-called “French Paradox” presented a tantalizing puzzle to scientists. How was it that the French – many of whom are heavy smokers – were able to maintain a diet almost as fat-laden as that of Americans, and yet failed to develop heart disease at a similar rate? Early research done during the last decade of the century seemed to indicate unequivocally that protective agents from red wine were what made the difference. Further research identified the plant chemical resveratrol, a polyphenol plentiful in the skins of red grapes, as the most likely candidate for the specific cardioprotective agent they were seeking.
Numerous in vitro and animal studies have supported the therapeutic potential of resveratrol in coronary heart disease. For example, a 2000 study in Taiwan (Hung et al.) showed that resveratrol’s antioxidant activity and the increase in nitrous oxide production it caused protected rats from arrhythmia (variation from the normal rhythm of the heartbeat) during ischemic reperfusion (the restoration of normal blood flow to an area experiencing obstruction of blood flow). In 2001, a study from the New York Medical College (Wu et al.) described the
mechanisms that may enable resveratrol to protect the heart. Other studies have demonstrated that resveratrol can help lower levels of “bad cholesterol,” or low-density lipoprotein (LDL), which causes atherosclerosis. A placebo-controlled Greek study in 2005 (Lekakis et al.), one of the few studies of resveratrol and CHD to use human subjects, demonstrated that an extract of red-grape polyphenols (including resveratrol) caused a significant improvement in cardiac endothelial function.
Subsequent research, like the 2009 Australian study cited in the Introduction, continues to bear out resveratrol’s effectiveness as an antioxidant. However, since most resveratrol research has been conducted on animals, it will be necessary to confirm those findings through clinical trials with human subjects. Also, it seems certain that merely drinking red wine will not provide sufficient resveratrol to protect the heart: a person would have to drink literally hundreds of bottles of wine daily to match the resveratrol dosage reported in the studies on mice.
Second only to coronary heart disease as a killer of Americans is cancer, in all its various forms. According to CA: A Cancer Journal for Clinicians, nearly 1,500,000 new cases of cancer and nearly 562,400 deaths from cancer are projected to occur in the United States in 2009. It is encouraging to note that research studies are discovering that resveratrol appears to show therapeutic potential not only for protection against heart disease, but also for cancer chemoprevention.
This was one of the most exciting findings of the Australian study previously cited – and one that has been independently verified by numerous other studies in the past few years. Associate professor Lindsay Brown, corresponding author for the study, says that “studies on the actions of resveratrol… were uncommon until research around 1997 showed prevention of cancers. This led to a dramatic interest in this compound."
In describing the connection found between resveratrol and cancer, Brown says that high doses of resveratrol increase “the process of apoptosis or programmed cell death to remove cellular debris… high-dose resveratrol prevents cancers.” Apoptosis is defined as “a form of cell death in which a programmed sequence of events leads to the elimination of cells without releasing harmful substances into the surrounding area.” Sometimes called “cell suicide,” apoptosis enables the human body to replace something like one million cells per second. The process gets rid of old or unhealthy cells, as well as cells that are unnecessary; but to maintain health, it is critical that just the right amount of apoptosis should take place. In this way, a high dose of resveratrol prevents cancers by tipping the delicate balance of apoptosis and killing cancerous cells.
One of those early studies in 1997, from the University of Illinois (Jang et al.), demonstrated that resveratrol acted as a chemical agent to prevent cancer in three major stages of its growth:
These results were obtained from in vitro assays.
From the University of Maryland School of Pharmacy in 1999 came a study showing that resveratrol had the ability to act against estrogen, to inhibit the growth of human breast cancer cells (Lu and Serrero). Currently in press, and due to be published soon in Cancer Letters (2009), is an article titled “Resveratrol and Chemoprevention” (Goswami and Das). These authors remind us that estrogen has often been associated with breast cancer in the scientific literature. They point to the fact that in breast cancer, resveratrol binds to estrogen receptors and prevents estrogen’s function of “inducing proliferation of human breast cancer cells”.
The benefits of resveratrol have also been documented in other forms of cancer. For example, in a 2005 study performed on hairless mice at the University of Wisconsin (Aziz et al.), researchers determined that a topical preparation of resveratrol had chemopreventive properties that protected against skin damage from ultraviolet-B (UVB) rays. The authors pointed out that “according to the World Cancer Report, skin cancer constitutes approximately 30% of all newly diagnosed cancers in the world, and solar ultraviolet (UV) radiation (particularly, its UVB component…) is an established cause of approximately 90% of skin cancers.” The urgency for developing new methods of preventing and treating skin cancer is clear. This study demonstrated for the first time that resveratrol has a strong chemoprotective effect against the transformation of normal skin cells into cancer cells through exposure to UVB. Aziz and his colleagues believe that this work may be the basis for the design of protective emollient creams or patches, as well as sunscreen and skin-care products, containing resveratrol.
Resveratrol has also been studied recently in relation to pancreatic cancer, or cancer of the pancreas. The survival rate for patients diagnosed with pancreatic cancer is very low. By the time of diagnosis, the cancer has generally spread to other organs, most often through the lymphatic system; therefore only a few patients can be saved by surgery. In a 2008 study at the University of Rochester Medical Centre on pancreatic cancer, resveratrol was found not only to cause apoptosis, but also to deprive cancer cells of their energy source. Chief of Radiation Oncology Dr. Paul Okunieff, who headed the study, stated: “Resveratrol seems to have a therapeutic gain by making tumor cells more sensitive to radiation, and making normal tissue less sensitive.” Researchers induced apoptosis by pre-treating cancer cells with resveratrol prior to irradiation.
An additional benefit of resveratrol observed in this study was that resveratrol was able to reach into and react with the mitochondria. Mitochondria convert nutrients into energy in the body, and are the main source of power for the cell when they are fully functioning. Since resveratrol can stop the flow of power to the cell, it can therefore help stop pancreatic cancer.
Of course, clinical trials will be necessary to confirm these data gleaned from laboratory studies. However, it seems certain from these and many other studies that resveratrol may be one of our most promising future treatments for cancer.
Human beings have always dreamed of finding a medicine that would act like the mythical “fountain of youth” and extend life indefinitely. To slow the aging process and add years to human life has been a goal of many biological scientists. New tests on resveratrol, along with several similar chemicals, were recently announced in the Science Times section of The New York Times (August 18, 2009). The article by Nicholas Wade stated that among a group of drugs called sirtuin activators, resveratrol seems to show the most promise.
The sirtuins are a class of proteins that are found in organisms ranging from bacteria to humans. Their function is to provide a link between available nutrients and energy metabolism. Calorie restriction helps to increase lifespan and provides benefits in various age-related diseases; and calorie restriction also activates sirtuin. For this reason, major research efforts are being focused on the development of chemicals and drugs that are sirtuin activators. Resveratrol appears to be at the top of the list of these.
Clinical trials of resveratrol have been initiated by Sirtris Pharmaceuticals, of Cambridge, Massachusetts. Sirtris was co-founded in 2004 by Dr. David Sinclair of the Harvard Medical School (who first identified the red wine ingredient resveratrol as a possible anti-aging drug) and Dr. Christoph Westphal, an MD/PhD described in Wade’s article as a “scientific entrepreneur.” GlaxoSmithKline, the world’s second largest pharmaceutical company, purchased Sirtris in 2008 for $720 million, to facilitate its studies of the sirtuins and enable more rapid development of sirtuin-related drugs to treat the many diseases associated with aging.
Animal studies preceding these new clinical studies have indicated that resveratrol, in addition to some small-molecule drugs that act in a similar manner, may be useful in treating such diseases as cancer, adult-onset diabetes, heart disease, Alzheimer’s disease, and Parkinson’s disease. Both Sinclair and Westphal strongly emphasize that their company is “working to cure diseases of aging, not to cure aging itself.” It is worth noting that the US Food and Drug Administration does not consider aging to be a disease, and therefore does not give its approval to any drugs that purport to “cure aging.”
It may be overly simplistic to say that resveratrol slows aging. However, there is mounting evidence that as a potent sirtuin activator, resveratrol is likely to be effective against one or more of the diseases that make aging difficult and unpleasant for many people. A person who is 80 years old, taking a resveratrol dosage prescribed by a doctor, and totally free of any of the “aging diseases,” might be living life with as much zest and energy as a person of 40! In such a case, that person might feel justified in insisting that resveratrol does slow aging.
Scientists have many points of view in discussions about the human lifespan. As Wade says in his article: “All that seems clear about life span is that it is not fixed. And if it is not fixed, there may indeed be ways to extend it.” The newest tests on resveratrol show that biological scientists are exploring that possibility – right now.
Alzheimer’s disease (AD), a progressive and fatal brain disorder, is presently the seventh leading cause of death in the United States. Currently, some 35 million people worldwide are living with Alzheimer’s and dementia. As the global population of older people continues to grow, Alzheimer’s has become an urgent healthcare problem, and the focus of a great deal of scientific research. Among recent discoveries that may have a bearing on AD, resveratrol seems to show a great deal of promise.
Perhaps the most important of these studies focusing specifically on resveratrol and Alzheimer’s was published in the Journal of Biological Chemistry (Marambaud et al., November 11, 2005). Dr. Philippe Marambaud’s team at New York’s Litwin-Zucker Research Center for the Study of Alzheimer’s Disease and Memory Disorders began their research on the basis of an earlier “large body of epidemiological evidence linking wine consumption to lower risk of dementia.” They tested resveratrol and several other antioxidant compounds against beta-amyloid, a protein in the brain that has led some researchers to develop “the amyloid hypothesis” as a possible explanation for the cause of Alzheimer’s disease. Marambaud reported that resveratrol’s neuroprotective power did not stop the production of beta-amyloid, but it did stimulate its breakdown. Of all the antioxidants tested against beta-amyloid, only resveratrol had this effect. Such destruction of beta-amyloid could be a useful mechanism for therapy against Alzheimer’s disease, according to Marambaud.
It is important to note that only red wine – not liquor, beer, or other alcoholic products – shows the link between resveratrol and Alzheimer’s. Other alcoholic beverages do not contain grapes, and so do not contain resveratrol. The Canadian Study of Health and Aging in 2002 determined that the risk of AD could be reduced by as much as 50% by moderate wine consumption. In this five-year study and in this population, wine intake “was found to be even more protective than the use of nonsteroidal anti-inflammatory drugs (NSAIDs)”.
A more recent study titled “Therapeutic potential of resveratrol in Alzheimer’s disease” (Vingtdeux et al., 2008) stated that “in vivo data have clearly demonstrated the neuroprotective properties of the naturally occurring polyphenol resveratrol in rodent models for stress and diseases.” Although the notion that resveratrol may lower the risk of Alzheimer’s disease still remains somewhat controversial, resveratrol’s neuroprotective power continues to be borne out by scientific investigation like that of Valérie Vingtdeux and her team at the Litwin-Zucker Research Center in New York.
Ongoing research strongly supports the idea that for many diseases associated with aging – including Alzheimer’s disease and other neurodegenerative diseases like Parkinson’s and Huntington’s – resveratrol may have the potential to slow or stop disease progression. Such research also offers the possibility for developing powerful synthetic analogs – drugs based on resveratrol, and possessing resveratrol’s neuroprotective power. These analogs may provide us in the near future with a way to reverse the symptoms of Alzheimer’s disease.
The red wine ingredient resveratrol has been shown in many research studies to have a positive effect on such diseases of aging as coronary heart disease, hypertension, cancer, stroke, and diabetes. According to David Byrne, the European Union Commissioner for Health and Consumer Protection, all these diseases may be triggered by obesity. “Obesity is the major emerging threat to public health in Europe,” said Byrne, writing in the Spring 2003 issue of EuroHealth. And we already know that Americans are shockingly overweight:
Even in people who are not suffering from any of the above diseases, but who are obese, overweight, or just thinking of taking off a few pounds, there seem to be other connections between resveratrol and obesity. In some studies, it has been observed that metabolic activity was increased by resveratrol. The compound is a sirtuin activator: that is, it has the ability to activate the gene called SIRT1. This gene has been identified as a powerful fat burner, as well as a “longevity gene.”
In November 2006, Dr. David Sinclair of Harvard Medical School , co-founder of Sirtris Pharmaceuticals ( see page 8 ), along with other scientists from Sirtris, published a ground-breaking paper in the journal Nature. It described a study on resveratrol that demonstrated its potency as a SIRT1 activator: it was able to increase the stamina of mice two-fold and extend their lifespan by 40%, even though they were maintained on a high-fat diet. In fact, states the article, “resveratrol shifts the physiology of middle-aged mice on a high-calorie diet towards that of mice on a standard diet and significantly increases their survival.”
The very next month, a French team of researchers published a study in Cell showing that feeding large amounts of resveratrol to healthy young mice almost doubled their physical endurance during exercise. In addition, resveratrol treatment “protected mice against diet-induced obesity and insulin resistance.” Implications here for resveratrol and weight loss in humans might be that if physical endurance were increased, more exercise could be helpful in losing weight.
Numerous studies by international researchers followed in the wake of these two articles. Resveratrol was suddenly the “compound du jour,” of interest to almost everyone. For example, in April 2009 Spanish scientists Francisco Alcaín and José Villalba, at the Universidad de Córdoba, published a study discussing the activation of the sirtuin genes by the restriction of caloric intake. The article in Expert Opinion on Therapeutic Patents states their conclusion that “to date, resveratrol is the most potent natural compound able to activate SIRT1, mimicking the positive effect of calorie restriction.”
Although clinical trials in humans have not yet been conducted for resveratrol as a treatment for obesity, animal studies continue to suggest that resveratrol might assist in weight loss. If it mimics “the positive effect of calorie restriction” – read calorie-reduced dieting – and it also increases physical stamina, thus making it possible for overweight and obese individuals to exercise more… it certainly seems plausible that resveratrol could be beneficial in this way. Talk with your physician if you’re considering taking resveratrol for weight loss, as you would before taking any other non-prescription health preparation.
In the last few years, the phytochemical compound resveratrol has gained a great deal of attention, both from researchers and from the general public. Clinical studies appear to show that resveratrol benefits the heart, helps control weight, increases energy, and may be effective against many of the so-called “diseases of aging.” The media have picked up on resveratrol as the fabled “fountain of youth”: CBS’s “60 Minutes” interviewed Dr. David Sinclair and Dr. Christoph Westphal in January 2008 and again in January 2009, updated in May 2009.
In the wake of this wave of publicity, the number of resveratrol supplements available online and in health food stores has increased almost exponentially. Now the big question seems no longer to be “Do the benefits of resveratrol justify taking resveratrol supplements?” Instead, it’s “How can I be sure I’m buying high-quality resveratrol supplements?”
The first thing to look for on the label of resveratrol supplements – as well as on the labels of any other dietary supplements you may be considering – is the circular logo of the National Sanitation Foundation’s Food Manufacturing Practices. Since its founding in 1944, NSF International has been working in the areas of safety, public health, and environmental protection. It develops standards, provides product testing, and certifies products that meet its standards. Where you see “NSF GMP,” you can be confident that the product comes from production and packaging facilities that have been inspected by NSF. In addition, NSF annually retests certified resveratrol supplements (and other products) to ensure that compliance with stringent testing standards continues. When you choose an NSF-certified supplement, you can be sure
Next, to make sure you’re getting high-quality resveratrol supplements, you should check the label to be certain the product contains trans-resveratrol. The resveratrol molecule can break down if it is exposed to heat, light, and oxygen during the production and storage of supplement capsules. When this degradation occurs, the more active form, trans-resveratrol, can modify to the less-active cis-resveratrol. Trans-resveratrol and cis-resveratrol are two isomers of the resveratrol molecule. Therefore, to make sure you’re getting the greatest benefits of resveratrol, you’ll want to be taking a supplement that provides you with trans-resveratrol.
Finally, if you’re serious about finding high-quality resveratrol supplements, stay away from any online company that offers free trials of its resveratrol supplements, or that promotes the marvelous properties of resveratrol with “celebrity endorsements.” According to an article in the New York Times Science section (August 18, 2009), “After resveratrol received attention on “60 Minutes” … the Internet swelled with Web sites making unproven health claims and using false celebrity product endorsements for anti-aging and weight-loss pills made from resveratrol.”
The free-trial offers always have (in very tiny print) a caveat that ordering the free trial sets you up with an auto-delivery program, usually to begin 30 to 60 days after you receive the free trial supplements. These can be very difficult to cancel; several companies have no way to contact them directly and speak to a representative to cancel an auto-delivery shipment.
As for the “celebrity endorsements,” these advertisements may include a photograph of the celebrities, and give the impression that these individuals not only use the product themselves, but recommend its use by others. Steer clear of such advertisements. It’s all hype.
If you’re careful about the resveratrol supplements you select; read the labels carefully and know what you’re looking for; and if you avoid being too credulous of the ads you’ll see on television and the World Wide Web, you should be able to locate high-quality resveratrol supplements. And if you take them as directed, you may find yourself feeling better, more energetic, and confident that you’re doing something that recent research shows to be beneficial and healthful.
Resveratrol seems to be everywhere in the news these days. But another plant-based chemical, quercetin, has begun to attract attention from researchers as well. Recent studies suggest that resveratrol and quercetin might actually be more effective when taken together.
Both resveratrol and quercetin are polyphenols, a group of antioxidant chemicals found in many fruits and vegetables. As previously mentioned, an “antioxidant” is a compound that destroys free radicals in the body, those atoms with unpaired electrons that cause damage to tissues and cells as they roam the body scavenging electrons from other atoms. The polyphenols have been found to have such health benefits as lowering low-density lipoprotein (LDL = “bad”) cholesterol in the body, and reducing the risk of heart disease and cancer.
In fact, many scientists believe that the polyphenols may be some of our most powerful natural agents for the prevention of chronic diseases of aging, and even for slowing the aging process. Resveratrol is found in the skins of red and purple grapes, and in dark-colored berries and peanuts. Good sources of quercetin are onions, especially red onions, cranberries, tomatoes, and the skins of apples. Significant quantities of both quercetin and resveratrol are present in red wine. Although both resveratrol and quercetin are polyphenols, of the two, only quercetin is classed as a flavonoid. These plant pigments provide color in fruits, vegetables, and flowers – and wine as well.
Some recent research has suggested that quercetin boosts resveratrol. Impressive as the effects of resveratrol may be alone, it seems they may be enhanced by working together with quercetin. Although resveratrol shows a high rate of absorption when taken orally, its bioavailability is relatively low, because it is metabolized and eliminated very rapidly. Several in vitro studies point to the flavonoid quercetin, which inhibits some of the enzymes that enable the conversion of resveratrol to its metabolites in the body. In addition, quercetin appears to prevent the sulphation (conversion to a salt of sulphuric acid) of resveratrol within the gut. Both of these actions increase the rate and amount of the compound that is absorbed by the gastrointestinal tract.
Another example of a way in which resveratrol is enhanced by quercetin is reported in a 2008 in vitro (test tube) study (Yang et al.). Researchers investigated the effects of various combinations of quercetin and resveratrol on adipogenesis and apoptosis. Adipogenesis is the formation of fat cells, or adipocytes; and apoptosis is the process of programmed cell death, by which the body naturally rids itself of old, unhealthy, or excess cells. When maturing fat cells were treated with resveratrol and quercetin separately, resveratrol suppressed fat accumulation by 9%, while quercetin suppressed it by 15%. However, when given in combination, fat accumulation in the cells was decreased by more than 68%.
In addition, resveratrol and quercetin, administered individually, induced programmed cell death in mature fat cells by 18% and 15%, respectively. Given together, they increased apoptosis in mature adipocytes more than the single compounds did. These data may have significant implications for the development of products using resveratrol and quercetin for weight loss. The researchers stated, “Taken together, our data indicate that combinations of resveratrol and quercetin can exert potential anti-obesity effects by inhibiting differentiation of preadipocytes and inducing apoptosis of mature adipocytes.”
Some research scientists believe that the combination of resveratrol and quercetin may not be the only synergistic possibility. It may be that a group of five compounds can work together in synergy to offer protection against heart disease and cancer. Resveratrol and quercetin, vitamin E, vitamin C, and selenium (a trace mineral) are being investigated together with this goal in mind.
Resveratrol, a molecule that is found in many plants, has attracted much attention by the scientific community in recent years. Both in vitro and in vivo studies (the latter mostly in rodents) have shown that large doses of resveratrol show some efficacy in delaying the aging process in yeasts, short-lived fish, and mice. Scientists hope that past and current studies may help in developing new drugs based on resveratrol and its metabolites, which will benefit humans by protecting against heart disease, cancer, diabetes, and other so-called “diseases of aging.”
Clinical trials of resveratrol have only begun. Many more such studies will be necessary before we can assess the true action and value of Resveratrol to humans. The long duration of any clinical trial that would be required to evaluate the anti-aging properties of resveratrol or a resveratrol-like drug has been a prohibitive factor.