Alcohol, and especially red wine, occupies a unique place in our cultural and gastronomic heritage. Its history dates back to the arrival of the Phocaeans in Marseille, more than 2,600 years ago, marking the beginning of a wine-growing tradition that would transform our terroirs and our art of living. Even if the wines drunk by our ancestors from the ancient period had little to do with those we consume today, red wine remains popular in our region. According to Statistain 2022, 57% of French people preferred red compared to its white (40%), rosé (29%) or sparkling (26%) counterparts.
However, this has certainly not escaped some of you, drinking red wine can give you a headachenot to mention a hangover in the strict sense of the term. A somewhat less glorious phenomenon associated with the consumption of red wine, which can occur even without abuse. So where do these headaches come from?
Traditional suspects: a story of erroneous presumptions
The search for those responsible for these headaches has long focused attention on several compounds in red wine. Sulphites, since their mandatory mention on American labels in the 1990s, have long crystallized concerns. These are sulfur compounds naturally present in grapes, but they are also added to wine by winemakers for several reasons: to prevent the wine from oxidizing, to protect it from the proliferation of bacteria and to ensure that it retains its aromas.
This suspicion quickly extended to other compounds such as biogenic amines (nitrogenous compounds produced by certain bacteria present in wine) and tannins (molecules present in grapes which give wine its structure, its astringency and its ability to grow old), creating a veritable catalog of alleged culprits. However, these accusations were based on fragile foundations.
Examining the role of sulphites in our body reveals a very different reality. The latter naturally produces 700 mg of sulphites daily, a quantity significantly greater than the 20 milligrams contained in a glass of wine. Sulfite oxidases, specialized enzymes, effectively ensure their transformation into sulfate, invalidating their presumed role in the appearance of headaches. Furthermore, the equivalent presence of sulphites in white wines, rarely associated with headaches, further weakens this hypothesis.
Biogenic amines, compounds found in many fermented foods, have also been investigated. Although capable of causing headaches, their concentration in red wine remains too low to explain the symptoms observed. As for tannins, their presence in other foods such as tea or chocolate, consumed without causing similar headaches, calls into question their direct involvement.
Quercetin: the big culprit?
The real explanation lies in a biochemical interaction between alcohol and a specific phenolic compound: quercetin. It is a natural grape pigment, which plays a key role in the aromatic complexity of wines, providing floral and fruity nuances; during the maturation of the wine, this is released, which also gives it its color.
The metabolism of alcohol (ethanol) is carried out in a two-step processeach involving specific enzymatic mechanisms. First, ethanol transforms into acetaldehyde, a potentially toxic molecule. The second step, catalyzed by the enzyme ALDH (aldehyde dehydrogenase), then converts this acetaldehyde into acetate, a substance that is harmless to the body.
This research published in 2023 in the magazine Nature demonstrated that quercetin, particularly abundant in the skin of red grapes, specifically interferes with this second step by blocking the activity of ALDH. This discovery results from enzymatic analyzes carried out in vitro, which made it possible to evaluate the impact of different phenolic compounds on the activity of ALDH. Quercetin glucuronide, the form in which quercetin is metabolized by the liver, has been shown to be the most potent inhibitor of this key enzyme.
This interaction causes an accumulation of acetaldehyde in the body, triggering a cascade of inflammatory events. This phenomenon explains not only the headaches, but also the facial redness that some people experience after drinking red wine. Genetic variation in the effectiveness of ALDH between individuals also explains why some people are more sensitive than others to these effects.
On the other hand, quercetin alone, present in many foods such as apples, cabbage or capers, does not cause headaches. This is its association with alcohol which triggers the problematic mechanism. The quercetin content varies depending on the exposure of the vines to the sun: sunnier grapes produce more. Lighter vintages, often from less exposed vines, could be a gentler alternative for sensitive people. If you are affected by this problem, then avoid Bordeaux and Côtes du Rhône (notably Grenache, Syrah, Mourvèdre) and prefer fruity and light red wines. Pinot Noir, Gamay or Cabernet Francs from the Loire, for example. All in moderation, of course..
- Red wine headaches do not come from sulfites, tannins or amines, which are often wrongly blamed.
- A molecule called quercetin, interacting with alcohol, blocks a key enzyme, causing toxic buildup.
- Favoring light red wines made from grapes less exposed to the sun can limit these inconveniences.
