Researchers at the University of California at Davis (USA) have discovered why some people cannot drink red wine, even in small quantities, without experiencing a headache. The culprit is quercetin, a flavanol found naturally in red wines that interferes with the proper metabolism of alcohol and causes headaches.
According to lead author Apramita Devi, when quercetin reaches the bloodstream, it is converted into quercetin glucuronide, which blocks the metabolism of alcohol and leads to an accumulation of acetaldehyde toxin in the body. This can cause redness, headache, and nausea.
The study also reveals that about 40% of the East Asian population has an enzyme that doesn’t work very well, allowing acetaldehyde to build up in their systems. This explains why people from this region may be more susceptible to experiencing negative reactions when consuming red wine.
The researchers believe that when susceptible individuals consume wine with even modest amounts of quercetin, they develop headaches, particularly if they have a preexisting migraine or other primary headache condition. They plan to conduct a clinical trial with red wines that contain a lot of quercetin and red wines with very little to test their theory about red wine headaches in people.
It’s important to note that levels of quercetin can vary dramatically in red wine. Quercetin is produced by grapes in response to sunlight and can differ depending on how the wine is made. Skin contact during fermentation, fining processes, and aging are all factors that can affect quercetin levels in red wine. The scientists are working on identifying specific factors that contribute to higher levels of quercetin in certain types of wines.