REPORT by Elisabeth Holmgren

Elisabeth Holmgren is the Director of the Department of Research and Education at Wine Institute. She is responsible for developing and managing public policy, research and education programs related to the wide variety of health and social issues that impact the wine industry.

Wine Antioxidants and Health:
In Search of Answers

Wine has long had a certain mystique to it, due perhaps to its rich history and its subtle flavors and varieties. But when it comes to scientific research and health effects, mystery can be a detriment. If we are going to continue believing that wine offers benefits above and beyond those contributed by alcohol alone, scientists are going to have to fully identify, quantify and analyze wine's many complex compounds to determine which are responsible for wine's salutary effects.

Just a handful of years ago we thought of tannins and other phenolic compounds as elements that gave wine its flavor, color and character. Today we know that some of these are also powerful antioxidants capable of preventing disease. Scientists around the world have been hard at work these past few years trying to unlock the secrets of flavonoids and other compounds to determine what exactly it is about wine that appears to help moderate wine drinkers live longer, healthier lives.

Recently researchers at Harvard University suggested that all alcoholic beverages may offer uniform effects with respect to heart disease based solely on their ethyl alcohol content. Given the newly emerging research trends on wine-based antioxidants, many other scientists believe it is premature to discredit the hypothesis that wine's vast array of complex compounds may contribute to specific, positive benefits for wine drinkers.

At a symposium last month on wine and health sponsored by the American Society for Ecology and Viticulture, eminent cardiology researcher Dr. John Folts from the University of Wisconsin discussed recent research on antioxidants. Known for his work in the 1970s on the cardiovascular benefits of aspirin, Folts has been studying wine antioxidants this decade, basing his conclusions on animal models and human volunteers. His work has recently focused on platelet-mediated thrombosis (e.g. heart attacks) caused by a blood clot suddenly forming, breaking loose and blocking the blood flow in a vital coronary artery.

In their animal model, Folts and colleagues found that alcohol can prevent dangerous platelet activity only at very high levels of blood alcohol (BAC), but "when wine is given, activity drops at lower BAC levels." Other trials found red wine to inhibit human platelet activity as well. "Thus, there is something in wine besides the alcohol that inhibits platelets," Dr. Folts stated. Citing large-scale studies that found inverse relationships between flavonoid intake and death from coronary heart disease, Folts believes that the phenolic compounds found in wine and other sources have potential health benefits as both platelet inhibitors and antioxidants, and that there may be a future in commercial flavonoid supplements as a way to protect us from heart disease.

Other researchers from countries throughout the world have also been busy examining wine phenolics as well, and the evidence of positive effects is growing. Recent studies include the following:

  • In the United States, a study reported that a combination of phenolic compounds, depending on their structural makeup, play an important role in inhibiting damaging LDL cholesterol oxidation.

  • In Canada, a study found the certain wine compounds, particularly trans-resveratrol and quercetin, inhibit platelet aggregation and fatty acid synthesis. These phenolics blocked two forms of potentially detrimental platelet aggregation while ethyl alcohol alone blocked just one.

  • In the United Kingdom, a study reported that wine, particularly red wine, raised subjects' serum antioxidant capacity. This is another indicator of how wine phenolics are absorbed into the bloodstream and may reduce the risk of disease in a way that ethyl alcohol alone does not.

  • In Spain, a study showed that significant amounts of potentially beneficial phenolic compounds are also found in the grape seeds often present in the winemaking process.

While more research like this is needed to gain a more complete understanding of the active compounds in wine and their potential benefits, we must keep in mind that the whole subject area of antioxidants in health and nutrition is new. Many general questions still need to be addressed. For example, should antioxidants be considered required nutrients similar to vitamins and minerals? Can diet-based antioxidants, including those in wine, help prevent not only heart disease but cancer and increase immunity to other chronic diseases? Are antioxidants effective in isolation, as in commercially made supplements (there are already wine antioxidant pills) or are they only helpful if consumed from a natural source containing a team of antioxidants designed by nature to work synergistically?

In studies that find wine-specific benefits, many researchers have attributed the results to the possible interaction between alcohol and phenolic compounds in wine. Researcher Dr. Martin Weisse, whose recent study found wine to eradicate food-borne bacteria better than bismuth salicylate (the active ingredient in Pepto Bismol) as well as diluted alcohol and Tequila, wrote in the British Medical journal, "The antimicrobial agent in wine seems to be a polyphenol that is liberated during fermentation." We need to address this difficult area: Does the fermentation process "liberate" antioxidant activity? Does alcohol act as a solvent to release antioxidants or as a catalyst? Research on de-alcoholized wines has not yet yielded conclusive results.

Despite all the remaining questions, wine antioxidant research has resulted in some promising leads.

Despite all the remaining questions, wine antioxidant research has resulted in some promising leads. Different phenolic compounds have been isolated, identified, and associated with beneficial effects. Thanks to pioneering researchers Dr. Folts and from Drs. Frankel, Waterhouse and German at the University of California, Davis, we have learned that wine-based antioxidants appear to be beneficial in two ways: they help prevent unhealthy LDL cholesterol from being oxidized into artery-clogging plaque and they help prevent the formation of unhealthy internal blood clots.

These are important discoveries, but they signify only the beginning of a whole new area of scientific investigation for wine and health. Wine may lose a little mystery along the way as each of its hundreds of components is more fully understood. But mysterious or not, wine should continue to be a pleasing and healthy mealtime beverage choice.

For additional information on any of the research studies mentioned in this article, please contact the Department of Research and Education at Wine Institute at (415) 512-0151.

© 1996 Wine Trader. All rights reserved.

WineTrader Web Pages are designed, hosted and maintained by Wines on the Internet. HTML and graphics reproduction rights reserved.
Latest Update: September 22, 1996 E-Mail: