The flavonoid interferes with the metabolism of alcohol.
The intense hangover after drinking large amounts of alcohol is related to genetics, metabolism of alcohol (ethanol), sulphites, and congeners (compounds created by ethanol fermentation).
But wine products also contain other substances including tannins and histamine that can trigger headaches.
But when it comes to the “red wine headache” phenomena, there might be a different explanation.
Quercetin
Scientists think there must be other reasons that some people who are not heavy drinkers experience red wine headaches.
These headaches can occur 30 minutes to three hours after drinking a small glass of red wine.
Researchers came up with a theory that an antioxidant called quercetin may trigger headaches by interfering with the metabolism of alcohol.
That makes sense since quercetin levels are much higher in red wine than other alcoholic drinks, including white wine.
Professor Andrew Waterhouse, the study’s senior author, explains how this healthy flavonoid interferes with alcohol:
“When it gets in your bloodstream, your body converts it to a different form called quercetin glucuronide.
In that form, it blocks the metabolism of alcohol.”
Toxin acetaldehyde
Ethanol is converted to toxic acetaldehyde in the body and than is metabolized by the ALDH2 enzyme to acetate.
If this fails than the acetaldehyde toxin would build up in the body causing symptoms such as headache, nausea, facial flushing, and excessive sweating.
Ms Apramita Devi, the study’s first author, said:
“Acetaldehyde is a well-known toxin, irritant and inflammatory substance.
Researchers know that high levels of acetaldehyde can cause facial flushing, headache and nausea.”
Nearly half of East Asian population experience these symptoms after a drink because their enzyme doesn’t work properly and so toxins builds up in their body.
Alcoholics who take drugs such disulfiram to overcome drinking also experience similar symptoms because the medication blocks the enzyme that breaks down acetaldehyde.
This study suggests that quercetin produces similar adverse effects by blocking ALDH2 which would result in accumulation of the toxin.
Professor Morris Levin, study co-author, said:
“We postulate that when susceptible people consume wine with even modest amounts of quercetin, they develop headaches, particularly if they have a preexisting migraine or another primary headache condition.”
Grapes and the sunshine
The higher the exposure to sunlight, the more flavanol in red grapes.
Normally red wines with better quality are produced from grapes that are grown with care and in sunnier climates.
Therefore, these type of grapes contain greater levels of quercetin.
The levels are also influenced by the process of wine making such as removing unwanted material known as fining, skin contact during fermentation, and aging.
Professor Waterhouse said:
“Quercetin is produced by the grapes in response to sunlight.
“If you grow grapes with the clusters exposed, such as they do in the Napa Valley for their cabernets, you get much higher levels of quercetin.
In some cases, it can be four to five times higher.”
Related
- Different types of alcohol are linked to different emotions.
- A diet low in flavanols is linked to age-related memory loss.
- ‘Good’ Wine Increases Food Consumption by 12%.
- One or two glasses of wine can make the drinker look more attractive.
The study was published in the journal Scientific Reports (Devi et al., 2023).
