Not all are fine, some people get headaches from drinking red wine?

In a new study, scientists at the University of California, Davis, examined "red wine headache" why this happens -- even to people who don't get headaches when drinking small amounts of other alcoholic beverages.

A red wine may pair nicely with the upcoming Thanksgiving meal. But for some people, drinking red wine even in small amounts causes a headache. Typically, a "red wine headache" can occur within 30 minutes to three hours after drinking as little as a small glass of wine.

Researchers report that a flavanol found naturally in red wines can interfere with the proper metabolism of alcohol and can lead to a headache. The study was published in the journal Scientific Reports.

This flavanol is called quercetin and it is naturally present in all kinds of fruits and vegetables, including grapes.It's considered a healthy antioxidant and is even available in supplement form. But when metabolized with alcohol, it can be problematic.

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

Scientists will next compare red wines that contain a lot of quercetin with those that have very little to test their theory about red wine headaches on people. It's unclear why some people seem more susceptible to them than others.

Researchers don't know if the enzymes of people who suffer from red wine headaches are more easily inhibited by quercetin or if this population is just more easily affected by the buildup of the toxin acetaldehyde.

Reference: Apramita Devi, Morris Levin, Andrew L. Waterhouse. Inhibition of ALDH2 by quercetin glucuronide suggests a new hypothesis to explain red wine headaches. Scientific Reports, 2023; 13 (1) DOI: 10.1038/s41598-023-46203-y.