In Summary
- Researchers from California University say it is due to a compound in red grapes that can mess with how the body metabolises alcohol.
- The compound is an antioxidant or flavanol called quercetin.
Some people usually suffer from headache immediately after drinking red-wine which they don’t know the reason as to why it is happening.
US researchers say they may have discovered why some people get a headache after just one small glass of red wine,even though they are fine drinking other types of alcohol.
Researchers from California University say it is due to a compound in red grapes that can mess with how the body metabolises alcohol.
The compound is an antioxidant or flavanol called quercetin.
Some of the reasons why Red-wine causes headache
High-quality grapes

Red grapes make more quercetin when they are exposed to sunshine.
And that means more expensive red wines,rather than cheap reds,would be worse for headache-prone people.
The cheap grape varieties are grown on vines with very large canopies and lots of leaves, so they don’t get as much sun whereas the high-quality grapes are from smaller crops with fewer leaves.
The amount of sunshine is carefully managed to improve the quality of the wine.
Amount of Sulphite
Several theories have been put forward to explain red-wine headaches, which can strike within 30 minutes of drinking even small amounts.
Some have suggested the cause might be sulphites – preservatives to prolong shelf-life and keep wine fresh.
Generally though, the sulphite content is higher in sweet white wines rather than reds.
And while some people can be allergic to sulphites and should avoid them, there is little evidence they are to blame for headaches.
Another possible culprit is histamine – an ingredient more common in red wine than white or rose.
Histamine can dilate blood vessels in the body, which might trigger headache. But again, absolute proof is lacking.
Toxic compound

Experts do know more than one in three people with East Asian heritage are intolerant of any type of alcohol – beer, wine and spirits – and will experience facial flushing,headaches and nausea when they drink.
This is because of a gene affecting how well an alcohol-metabolizing enzyme called ALDH2 or aldehyde dehydrogenase works.
Alcohol is broken down in the body in two steps – it is converted into a toxic compound called acetaldehyde, which ALDH2 then changes into harmless acetate, basically vinegar.
If this cannot happen, harmful acetaldehyde builds up, causing the symptoms.
And the researchers say a similar pathway is involved in red-wine headache.
They showed in the lab quercetin could indirectly block the action of ALDH2,through one of its own metabolites.