L. L. Creasy
Department of Fruit and Vegetable Science
Cornell University, Ithaca, NY
Resveratrol is a phytoalexin of grape made by grapevines to protect themselves from disease. It is also an active ingredient of several traditional human medicines. It is found in all grapes and grape products but in greatly different concentrations. Epidemiological studies continue to report that wine consumers have a significantly lower rate of coronary heart disease than abstainers. Six years ago, we proposed that resveratrol could contribute to this wine health benefit. A report this year found that resveratrol has antioxidant, antimutagenic and anti-inflammatory properties and inhibits cellular events associated with tumor initiation, promotion, and progression. Therefore, resveratrol is implicated in the prevention of heart disease, cancer and grape diseases.
We have reported the resveratrol concentration in New York wines since 1991. We established general parameters for resveratrol concentrations in grapes, wine, raisins and juice. In 1996, we conducted an extensive vineyard experiment to stimulate resveratrol accumulation in Pinot noir grapes near harvest. We ran several preliminary experiments to assure that the timing would be correct. Three hundred resveratrol analyses are required to finish the main experiment. Due to shortage of personnel, these berry analyses are only partly finished but are progressing satisfactorily. We also analyzed producer supplied wines and again they demonstrated that year to year fluctuation in resveratrol concentration is a fact of life. We found new highs in resveratrol concentration for the varietals Baco noir, Cabernet Franc and Merlot although Pinot noir wines average the highest year to year. All grape products contain some resveratrol, but wines from New York contain more resveratrol than those from other locations. Our trials making white wine with skin contact confirmed that we could produce high resveratrol white wine if techniques were developed to modify which skin components were retained in wine.
G. S. Stoewsand
Department of Food Science and Technology
New York State Agricultural Experiment Station, Cornell University, Geneva, NY
Ethyl carbamate (EC; urethane), a known carcinogen, can be naturally present in small amounts in wine. This study, using growing male, inbred C3H strain mice fed EC in wine for 41 weeks, showed a lower frequency of EC induced tumors in liver and lungs than mice receiving the same level of EC in water. From comparable tumor development frequencies in other groups of mice fed restricted amounts of ethanol or water, it appeared that the ethanol portion of wine, as well as lowered body weights in the wine-treated animals, were responsible for reducing EC-induced tumour frequency. Thus, the results of this study indicates that the ethanol content of wine, and reduced food intake with lowered body weights, protects against liver and lung EC-induced carcinogenesis.