- A ‘red-wine headache’ can cause migraines, flushes and nausea after a glass
- Experts say wines from sunnier regions are more likely to prompt a headache
A mystery of why red wine is more likely to give you a headache may have been solved by scientists.
Red wine is more of a trigger for headaches than spirits, white or sparkling wine, or beer, evidence shows.
A headache can start within only half an hour of drinking, after only one or two glasses of wine.
Now researchers have identified the likely cause – an antioxidant called quercetin which may prevent people processing alcohol properly.
This antioxidant is more abundant in grapes exposed to more sunlight.
Researchers at the University of California say a so-called ‘red wine headache’ can start in under 30 minutes and up to three hours after a small glass
So the good news for people who buy reasonably priced supermarket red wine is that it might be less likely to give them a headache – as more expensive varieties tend to be exposed to more sunlight.
Red wine from British vineyards may also be less likely to cause a headache, as it likely gets less sunshine than New World wines from Australia.
However more research is needed on this, and on how quercetin affects people directly.
So far scientists have only confirmed that it blocks an enzyme needed to break down alcohol in the body – and that inefficient breakdown can cause headaches.
Andrew Waterhouse, co-author of a study on the phenomenon, and professor emeritus at the University of California, Davis, said: ‘Alcohol is first converted into a compound called acetaldehyde, then into harmless acetate.
‘But we think quercetin stops the acetaldehyde being made into acetate, so it stays in the body, causes inflammation and a headache.
‘It means in the future people might be able to check the label for the amount of quercetin in a bottle of red wine, to try and reduce the chances of getting a headache, or we could put something into the wine to bind with the quercetin, so it can’t have this effect.’
Red wine has more quercetin because the full grapes are kept in the wine, while white wine has the skins and seeds removed.
Grapes produce quercetin to protect themselves from the sun, so those exposed to sun have up to eight times the level of it compared to those grown in shady vineyards.
Professor Waterhouse said: ‘We don’t know which red wines have the most quercetin, so are more of a headache risk.
‘However expensive wines tend to be exposed to more sunlight, as this makes them taste better, so people buying cheaper wines may have less risk of a headache.
‘Wines aged for more than a decade tend to build up a residue which may contain higher levels of quercetin, which is not usually consumed, so these might be safer for avoiding a headache too.’
Red wine headaches have been blamed on anything from alcohol to the tannins which give the wine its distinctive mouthfeel and the sulphites it contains.
However researchers knew that many people from Asian backgrounds, like people from Japan and Korea, are more likely to develop headaches after drinking alcohol and that they have a genetic variation which stops them breaking down acetaldehyde properly.
They started hunting for an ingredient in red wine which might have a similar effect to this genetic variation.
Quercetin, they found in the lab, similarly blocked the enzyme called mitochondrial aldehyde dehydrogenase, with the effect of acetaldehyde not being processed normally.
Morris Levin, professor of neurology and director of the Headache Centre at the University of California, San Francisco, and another researcher behind the theory, published in the journal Scientific Reports, said: ‘We postulate that when susceptible people consume wine with even modest amounts of quercetin, they develop headaches, particularly if they have a pre-existing migraine or another primary headache condition.
‘We think we are finally on the right track toward explaining this millennia-old mystery.
‘The next step is to test it scientifically on people who develop these headaches, so stay tuned.’