Scientists discover why some people get headaches from drinking red wine – and expensive bottles are MORE likely to cause them
A mystery about why red wine is more likely to give you headaches may have been solved by scientists.
Evidence shows that red wine causes more headaches than spirits, white or sparkling wine, or beer.
Headaches can start within half an hour of drinking, after just one or two glasses of wine.
Now researchers have identified the likely cause: an antioxidant called quercetin, which can prevent people from properly processing alcohol.
This antioxidant is more abundant in grapes exposed to more sunlight.
Researchers from the University of California say a so-called ‘red wine headache’ can start within 30 minutes and up to three hours after a small drink.
The good news for people who buy reasonably priced red wine from the supermarket is that it is less likely to give them a headache because more expensive varieties tend to be exposed to more sunlight.
Red wine from British vineyards may also cause fewer headaches because it is likely to receive less sunshine than New World wines from Australia.
However, more research is needed into this, and into the direct influence of quercetin on humans.
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 converted first into a compound called acetaldehyde and then into harmless acetate.
‘But we think quercetin prevents acetaldehyde from being converted into acetate, so it stays in the body and causes inflammation and headaches.
‘It means that in the future people might be able to look at the label to see the amount of quercetin in a bottle of red wine, to try to reduce the chance of a headache, or we might put something in the wine to bind to the quercetin . , so it can’t have this effect.’
Red wine has more quercetin because the full grapes remain 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 the sun have up to eight times as much of it as grapes grown in shaded vineyards.
Professor Waterhouse said: ‘We don’t know which red wines contain the most quercetin, and so pose a greater risk of headaches.
‘However, expensive wines are often exposed to more sunlight because this makes them taste better and people who buy cheaper wines are less likely to get headaches.
‘Wines that are more than ten years old tend to build up a residue that can contain higher levels of quercetin, which is not usually consumed, so these may also be safer for preventing headaches.’
Red wine headaches have been attributed to everything from alcohol to the tannins that give the wine its distinctive mouthfeel and the sulfites it contains.
However, researchers knew that many people of Asian background, such as people from Japan and Korea, are more likely to get headaches after drinking alcohol and that they have a genetic variation that prevents them from breaking down acetaldehyde properly.
They looked for an ingredient in red wine that could have a similar effect to this genetic variation.
Quercetin, they discovered in the laboratory, similarly blocked the enzyme mitochondrial aldehyde dehydrogenase, preventing the effect of acetaldehyde from being processed normally.
Morris Levin, professor of neurology and director of the Headache Center at the University of California, San Francisco, and another researcher behind the theory, published in the journal Scientific Reports, said: ‘We hypothesize that when sensitive people consume wine even in modest amounts from quercetin, they develop headaches, especially if they have a pre-existing migraine or other primary headache condition.
‘We think we are finally on the right track to explaining this millennia-old mystery.
‘The next step is to scientifically test it on people who develop these headaches, so stay tuned.’