A recent study published in ‘Science Advances’ provides insight into why some individuals cannot drink red wine, even in small quantities, without experiencing a headache.
Researchers from the University of California at Davis (USA) have discovered that a flavanol compound found naturally in red wines can interfere with the proper metabolism of alcohol and cause headaches. This flavanol is called quercetin and is present in all types of fruits and vegetables, including grapes. It is considered a healthy antioxidant and is consumed as a supplement, but when metabolized with alcohol, it can be problematic.
When quercetin reaches the bloodstream, it converts into quercetin glucuronide, which blocks the metabolism of alcohol. As a result, the buildup of acetaldehyde toxin causes redness, headache, and nausea. Acetaldehyde is a known irritant and inflammatory substance that can also cause facial redness and nausea when consumed in high levels. The medication disulfiram, prescribed to alcoholics to prevent them from drinking, causes these same symptoms because it also causes acetaldehyde to build up in the body when normally an enzyme would break it down.
The study suggests that susceptible individuals who consume wine with even modest amounts of quercetin may develop headaches, particularly if they have a preexisting migraine or other primary headache condition. However, there are still many unknowns about the causes of red wine headaches. It is not clear why some people seem more susceptible than others or if their enzymes are more easily inhibited by quercetin or if this population is simply more easily affected by the buildup of acetaldehyde toxin.
Furthermore, levels of this flavanol can vary dramatically in red wine depending on how it is made. Quercetin levels can differ depending on factors such as skin contact during fermentation, fining processes