Scientists have finally uncovered why that glass of cabernet gives you a pounding headache – and it’s not the sulfites or tannins most people blame.
At a Glance
- Quercetin, a plant pigment in red wine, may block alcohol metabolism enzymes, causing headaches
- People with East Asian ancestry face higher risk due to genetic variants affecting alcohol processing
- Sun exposure increases quercetin in grapes, making premium wines potentially more headache-inducing
- White wines and staying hydrated may help wine lovers avoid the dreaded “red wine headache”
The Quercetin Connection
Researchers at the University of California have identified quercetin, a natural plant pigment and antioxidant found in red grapes, as the likely culprit behind those notorious red wine headaches. This compound, present in varying levels depending on grape variety and growing conditions, appears to interfere with how our bodies process alcohol, particularly by blocking an enzyme called ALDH2 that helps break down alcohol’s toxic byproducts.
“The most interesting aspect of this project is that the effect is not direct. In other words, we found quercetin glucuronide to be the ‘culprit,’ but if you consume it in another food, you would not get a headache,” explains Dr. Andrew Waterhouse from UC Davis research team. “According to our hypothesis, a headache will only occur when quercetin and alcohol are consumed simultaneously. I think that is why it has taken so long to sort this out.”
That red wine headache might have a scientific explanation.🍷🧠 A study from @UCSF & @UCDavisHealth suggests that quercetin could be the culprit behind wine-induced headaches. UCLA Health's Dr. Eve Glazier & Dr. Elizabeth Ko give insight: https://t.co/XfQsJjnnx7
— UCLA Health (@UCLAHealth) March 15, 2025
How Quercetin Triggers Headaches
When you drink red wine, quercetin enters your bloodstream and converts to quercetin glucuronide. This compound blocks ALDH2, an enzyme responsible for breaking down acetaldehyde, a toxic byproduct of alcohol metabolism. When acetaldehyde accumulates, it causes headaches, flushing, and nausea – symptoms many wine drinkers know all too well. The reaction is similar to what happens when people take disulfiram, a medication used to treat alcohol dependence.
“Acetaldehyde is a well-known toxin, irritant and inflammatory substance,” explains study co-author Apramita Devi from UC Davis. This inflammatory response likely triggers the pain pathways that result in those pounding headaches after enjoying a glass or two of red wine.
Genetic Factors and Higher Risk Groups
Not everyone experiences red wine headaches with the same intensity. Genetic factors play a significant role in determining who suffers most. People of East Asian descent, particularly those from Japan, China, and Korea, have a higher risk due to genetic variants affecting the ALDH2 enzyme. These individuals often experience more severe reactions to alcohol in general, including flushing and headaches.
“People of East Asian origin, primarily from Japan, China and Korea, are among those at higher risk for red wine headaches,” according to the UC Davis study. Women may also be more prone to wine-induced headaches due to differences in body fat composition and alcohol metabolism rates.
Premium Wines May Cause More Headaches
Ironically, that expensive bottle of red might be more likely to cause a headache than cheaper options. Premium vineyards use practices that increase sun exposure to grapes, such as trellising, crop-thinning, and leaf clearance. These techniques produce higher-quality wines but also increase quercetin production in the grapes. Napa Valley cabernets and certain Australian varieties, known for their bold flavors, may contain particularly high quercetin levels.
“Mass-produced wines were found to have lower levels of quercetin,” notes Dr. Morris Levin, a headache specialist involved in the research. Other factors affecting quercetin content include how long grape skins contact the wine during fermentation, aging methods, and filtration techniques.
Avoiding Red Wine Headaches
For those susceptible to wine-induced headaches, several strategies may help. Switching to white wine is effective since white wines contain significantly lower levels of quercetin and other potential headache-triggering compounds. If you prefer red wine, pinot noir may be a better option due to its lower tannin content. Staying well-hydrated before and while drinking wine can also help reduce headache risk, as can avoiding drinking on an empty stomach.
While the quercetin theory represents a significant breakthrough in understanding red wine headaches, researchers caution that the hypothesis still requires further scientific validation through controlled clinical trials with affected individuals.
