A new University of California study published on November 20 in Scientific Reports found a possible link between red wine consumption, flavanols, and headaches. The compound to blame? A specific type of flavanol known as quercetin.

Quercetin is considered a healthy antioxidant, but it can cause issues during the metabolization process with the alcohol content in red wine. Study co-author Dr. Andrew Waterhouse, PhD, a wine chemist and professor emeritus at the University of California, Davis, said the research could help give consumers more information about how certain wines may impact their health.

“It’d be much better for consumers if there is some specific information available,” Waterhouse told Healthline. Although the research is still in its early stages, the results are compelling enough to lead to the next step in the research, human trials, which will be led by researchers at the University of California, San Francisco.

“I think if the human studies show a real effect, then it’ll be important for consumers to know which ones are high and which ones are low,” Waterhouse said.

What causes red wine headaches?

Red wine headaches typically occur within 30 minutes of consuming a glass. Prior theories have shown red wine headaches may be caused by:

According to the authors of the new study, however, flavanols could also be a possible cause. The flavanol quercetin — found in many different fruits and vegetables, including grapes and red wine — may affect how alcohol is metabolized. The researchers say that a common enzyme that helps metabolize alcohol in red wine, ALDH2, may be affected by the presence of quercetin in red wine, interfering with its role in the process.

This disruption in metabolization could increase toxic acetaldehyde levels, which may cause symptoms such as:

“When [quercetin] gets in your bloodstream, your body converts it to a different form called quercetin glucuronide,” Waterhouse said in a press release. “In that form, it blocks the metabolism of alcohol.”

More studies on flavanols and red wine headaches needed

Waterhouse’s interest in what causes red wine headaches began during a trip to Napa Valley, CA. “I’ve known about red wine headaches for some time, but I was talking to a winemaker in Napa Valley about other things. And he brought this up, mentioned that he got red wine headaches and was wondering what could cause it. So that sort of piqued my interest,” he said.

From there, Waterhouse and his colleagues explored the connection between inflammation, headaches, and who tends to get them after drinking certain types of alcohol. Interestingly, this research was funded via the crowdfunding program at UC Davis, and the Wine Spectator Scholarship Foundation will fund the next stage of the work.

Waterhouse said this approach was taken partly because his team believes that the early stages of this type of research should reduce their reliance on funding meant for projects with the potential for broader impact. “Suffering headaches after drinking red wine isn’t something, I think, that the government should be supporting, and they should be funding research that’s [about] more urgent diseases and things like that,” he said. “Now, when we get to the stage of taking those results and investigating what causes headaches, that would be appropriate for government-funded research.”

Research on the health effects of flavanols is ongoing

Research on the health properties of flavanols — particularly those found in chocolate — has been ongoing for decades, but it seems public interest in flavanols has recently surged.

In February 2023, flavanols reached its highest rating on Google Trends since Google launched the service in 2004.

Dr. Adam Brickman, PhD, a professor of neuropsychology at Columbia University who has studied the connection between flavanols, cocoa, and cognition, told Healthline the ongoing interest in studying flavanols makes sense as more information about the compound becomes known. Brickman was not involved in the new study.

“My take on it is that it’s not really surprising that many compounds in our food have bioactive properties. It’s where we get our energy from,” Brickman said.

“I think there’s been a lot of interest in whether there are aspects and foods or things that we consume that have beneficial effects on how we feel or how we think and other aspects that might be somewhat harmful.”


New research suggests that a type of flavanol, quercetin, which typically has health benefits, may cause red wine headaches. The findings suggest that quercetin may affect how alcohol is metabolized, which could lead to inflammation and cause nausea, flushing, and headaches. More studies are needed to determine this effect in humans.

By John Loeppky

Source: Healthline Media

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