• Posted November 21, 2023

Solving the Mystery of Why Red Wine Gives Some Folks Headaches

Countless corks will pop and wine will flow freely during the upcoming holiday season, but some people will pay a price for even the slightest bit of revelry.

For those unlucky folks, drinking red wine even in small amounts causes a headache, typically within 30 minutes to three hours after imbibing just a small glass.

But researchers now think they've cracked the mystery of why some people get "red wine headaches,"even if no other alcoholic drinks do the same.

Quercetin, a flavanol found in fruits and vegetables, appears to be the culprit, according to findings published Nov. 20 in the journal Scientific Reports.

Quercetin is considered a healthy antioxidant, but it can cause problems when the body processes it alongside alcohol, researchers say.

"When it gets in your bloodstream, your body converts it to a different form called quercetin glucuronide,"said co-researcher Andrew Waterhouse, a wine chemist and professor emeritus with the University of California, Davis Department of Viticulture and Enology. "In that form, it blocks the metabolism of alcohol."

In turn, quercetin's interaction with alcohol causes the body to start accumulating a toxin called acetaldehyde, explained lead author Apramita Devi, a postdoctoral researcher with the university's department of viticulture and enology.

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

Essentially, quercetin produces effects similar to Antabuse (disulfiram), a drug prescribed to alcoholics to deter drinking, Devi said.

Antabuse also causes acetaldehyde to build up in the body, blocking the action of an enzyme that would normally break the toxin down.

"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 co-researcher Morris Levin, director of the Headache Center at the University of California, San Francisco.

"We think we are finally on the right track toward explaining this millennia-old mystery,"Levin added. "The next step is to test it scientifically on people who develop these headaches, so stay tuned."

This small human clinical trial will compare the effects of red wines that contain high amounts of quercetin to those that have little, researchers said.

Levels of quercetin can vary dramatically in red wine, depending on the amount of sunlight that the wine-producing grapes are exposed to prior to harvest, Waterhouse said.

"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."

Quercetin levels in red wine also can differ depending on how the wine is made, researchers added.

Even if the link to quercetin is proven in clinical trials, it's still unclear why some people seem more susceptible to red wine headaches than others, researchers said.

It could be that some people have enzymes that are more easily inhibited by quercetin, or it might be that these folks are more sensitive to the buildup of acetaldehyde.

"If our hypothesis pans out, then we will have the tools to start addressing these important questions,"Waterhouse said.

More information

Harvard Medical School has more on red wine headaches.

SOURCE: University of California, Davis, news release, Nov. 20, 2023