Red Wine Headache? Blame the Sun

Haunted by red wine headaches? Then this new study is for you. Researchers from the University of California say that headaches caused by even a small glass of red wine may be linked to a compound called quercetin that's found in red grape skins, the BBC reports. Quercetin is an antioxidant, so it isn't problematic on its own, but it may disrupt how we metabolize alcohol. Per the New York Times, the study suggests that quercetin causes a toxic buildup from drinking that leads to headaches. "This puzzle has been around for literally thousands of years," said Dr. Morris Levin, an author on the paper and director of the Headache Center at the University of California, San Francisco.

Analysis from the study, published in the journal Scientific Reports, suggests that increased exposure of red grapes to sunlight results in higher quercetin levels (it's referred to as the "sunscreen for grapes" by Professor Andrew Waterhouse, an author on the study). This particularly applies to Cabernet wines from sunny regions like Napa Valley, and in an interesting turn, more expensive bottles. "The cheap grape varieties are grown on vines with very large canopies and lots of leaves, so they don't get as much sun," Waterhouse said. "Whereas the high-quality grapes are from smaller crops with fewer leaves."

Dr. Lara Ray, a specialist in alcohol use disorders, says the theory is a "compelling argument," but not everyone thinks it's a magic bullet. Factors like the additives in cheaper wines, allergies, and preservatives are other theories being looked into. "There are a lot of ingredients in wine that could conceivably cause a headache, not the least of which is just alcohol itself," Levin said. He told the Times that this scientific question hits home, as he recently developed an intolerance to reds. He hopes to identify which varieties cause better reactions. "I think I know which wines might be the more tolerable ones, but I'm not quite sure yet," he said. "So it's another experiment." (There's a new top wine-producing nation).