Why red wine gives some people a headache

Red wine, a popular choice for festive occasions like Thanksgiving, is known for its rich flavor and potential health benefits. However, it also brings an unpleasant experience for some – the dreaded “red wine headache.”

A recent study by scientists at the University of California, Davis, delves into the reasons behind this phenomenon, particularly in individuals who do not experience headaches from other alcoholic drinks.

Quercetin and red wine headaches

The research focuses on a specific flavanol found in red wine — quercetin. Commonly present in various fruits and vegetables, quercetin is a celebrated antioxidant, even available as a dietary supplement.

However, its interaction with alcohol in the bloodstream can cause issues. Wine chemist Andrew Waterhouse is a professor emeritus at UC Davis’s Department of Viticulture and Enology. He explains, “When it gets in your bloodstream, your body converts it to a different form called quercetin glucuronide. In that form, it blocks the metabolism of alcohol.”

The study’s lead author is Apramita Devi, a postdoctoral researcher at UC Davis. Devi points out that this interference leads to the accumulation of acetaldehyde, a well-known toxin.

“Acetaldehyde is a well-known toxin, irritant and inflammatory substance,” said Devi. “Researchers know that high levels of acetaldehyde can cause facial flushing, headache and nausea.”

These symptoms are similar to the effects experienced by individuals taking disulfiram, a medication prescribed to deter alcohol consumption.

Genetics and red wine headaches

Co-author Morris Levin, a neurology professor and director of the Headache Center at the University of California, San Francisco, suggests a link between these red wine headaches and genetic factors. Approximately 40% of the East Asian population possesses an enzyme less effective at breaking down acetaldehyde, increasing their vulnerability to these symptoms.

“We postulate that when susceptible people consume wine with even modest amounts of quercetin, they develop headaches, particularly if they have a preexisting migraine or another primary headache condition,” said Levin. “We think we are finally on the right track toward explaining this millennia-old mystery.  The next step is to test it scientifically on people who develop these headaches, so stay tuned.”

Wine production and grape cultivation

Waterhouse notes that quercetin levels in red wine can vary significantly, influenced by factors like grape exposure to sunlight and wine production methods. For example, grapes grown with exposed clusters, as in Napa Valley cabernets, tend to have higher quercetin levels.

“Quercetin is produced by the grapes in response to sunlight,” Waterhouse said. “If you grow grapes with the clusters exposed, such as they do in the Napa Valley for their cabernets, you get much higher levels of quercetin. In some cases, it can be four to five times higher.”

A small human clinical trial, funded by the Wine Spectator Scholarship Foundation and led by UCSF, is in the pipeline. This trial aims to test the red wine headache theory on people, comparing wines with high and low quercetin levels.

Unanswered questions

Despite these findings, several questions remain. The exact reason why some individuals are more prone to red wine headaches than others is still unclear. Researchers are uncertain whether it’s the individual’s enzymes being more susceptible to quercetin’s effects or a higher sensitivity to acetaldehyde buildup.

In summary, this study marks a significant step in unraveling the mystery behind red wine headaches. As Waterhouse concludes, “If our hypothesis pans out, then we will have the tools to start addressing these important questions.”

The research not only sheds light on a long-standing enigma but also paves the way for more personalized approaches to enjoying red wine without the fear of headaches.

The full study was published in the journal Scientific Reports.

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