Researchers at Johns Hopkins say they have discovered the way in which red wine consumption may protect the brain from damage following a stroke. Two hours after feeding mice a single modest（谦虚的，适度的） dose of resveratrol（白藜芦醇） , a compound found in the skins and seeds of red grapes, the scientists induced（引诱，说服） an ischemic（缺血的） stroke by essentially¹ cutting off blood supply to the animals' brains. They found that the animals that had preventively ingested（咽下，摄取） the resveratrol suffered significantly less brain damage than the ones that had not been given the compound.

Sylvain Doré, Ph.D., an associate professor of anesthesiology（麻醉学） and critical care medicine and pharmacology（药物学，药理学） and molecular² sciences at the Johns Hopkins University School of Medicine, says his study suggests that resveratrol increases levels of an enzyme³ (heme oxygenase血红素氧化酶) already known to shield nerve cells in the brain from damage. When the stroke hits, the brain is ready to protect itself because of elevated enzyme levels. In mice that lacked the enzyme, the study found, resveratrol had no significant protective effect and their brain cells died after a stroke.

"Our study adds to evidence that resveratrol can potentially build brain resistance to ischemic stroke," says Doré, the leader of the study, which appears online in the journal Experimental Neurology.

Red wine has gotten a lot of attention lately for its purported⁴ health benefits. Along with reducing stroke, moderate wine consumption has been linked to a lowered incidence of cardiovascular disease（心血管疾病，冠心病） — the so-called French paradox⁵（法国悖论） . Despite diets high in butter, cheese and other saturated⁶ fats（饱和脂肪） , the paradox goes, the French have a relatively⁷ low incidence of cardiovascular events, which some have attributed to the regular drinking of red wine.

Doré cautions against taking resveratrol supplements, available alongside vitamins and minerals and on websites touting⁸（兜售，招徕顾客） its benefits, because it is unclear whether such supplements could do harm or good. He has not tested resveratrol in clinical trials. And while resveratrol is found in red grapes, it's the alcohol in the wine that may be needed to concentrate the amounts of the beneficial compound. Doré also cautions that drinking alcohol carries risks along with potential benefits.

He also notes that even if further research affirms the benefits of red wine, no one yet knows how much would be optimal⁹ to protect the brain, or even what kind of red wine might be best, because not all types contain the same amount of resveratrol. More research is needed, he says.

Doré says his research suggests that the amount needed could end up being quite small because the suspected beneficial mechanism¹⁰ is indirect. "Resveratrol itself may not be shielding brain cells from free radical¹¹ damage directly, but instead, resveratrol, and its metabolites（代谢物，代谢分子） , may be prompting the cells to defend themselves," he suggests.

"It's not likely that brain cells can have high enough local levels of resveratrol to be protective," he says. The resveratrol is needed to jump-start this protective enzymatic¹² system that is already present within the cells. "Even a small amount may be sufficient," Doré says.

Doré says his ongoing¹³ research also suggests some therapeutic¹⁴ benefits to giving resveratrol to mice after a stroke to limit further neuronal（神经原的） damage.