Researchers from the United States claim they may have figured out why some individuals develop a headache after consuming a single small glass of red wine, despite the fact that they have no problem consuming other alcoholic beverages.

According to a team from the University of California, this is because of a compound in red grapes that can interfere with alcohol metabolism.

The flavanol antioxidant known as quercetin is the substance under scrutiny here. They argue that Cabernets from the warm and sunny Napa Valley have higher concentrations than wines from other regions.

The production of quercetin is increased in red grapes when they are subjected to sunshine.

This meant that headache-prone individuals would be more adversely affected by more expensive red wines as opposed to inexpensive ones, according to one of the researchers, Professor Andrew Waterhouse, who spoke to sources.

He explained that the inexpensive grape varieties receive less sunlight because they are grown on vines with dense foliage and immense canopies.

Conversely, superior grapes are derived from plants that are more compact in shape and possess a diminished quantity of foliage. In order to optimise the quality of the wine, the amount of sunlight is strictly regulated.

Professor Roger Corder, an authority on experimental therapeutics at Queen Mary University of London, told sources that anecdotal evidence suggested that inexpensive red wines were more detrimental to headaches. Therefore, it may be more enlightening to be aware of some of the additives used in the production of mass-market red wines at a lower price point.

Various hypotheses have been proposed to elucidate the phenomenon of red-wine migraines, which may manifest as early as 30 minutes after consuming even minute quantities.

Some have speculated that sulphites, which are preservatives used to maintain the freshness and storage life of wine, may be the cause. In general, however, saccharine white wines have a greater sulphite content than red wines.

while certain individuals may develop an allergy to sulphites and should therefore avoid them, there is little evidence that they are the cause of migraines.

Another potential offender is histamine, a compound that is more prevalent in red wine as opposed to white or rose.

Histamine is capable of dilatation of the blood vessels, which may result in a headache. Once more, however, absolute evidence is absent.

More than one in every three individuals with East Asian ancestry are intolerant to all forms of alcohol (beer, wine, and spirits), causing facial flushing, migraines, and nausea, according to experts. ALDH2, also known as aldehyde dehydrogenase, is an alcohol-metabolizing enzyme whose functionality is influenced by a gene.

In the body, alcohol is degraded in two stages: first, it is converted to acetaldehyde, a toxic compound; second, ALDH2 converts acetaldehyde to acetate, which is essentially vinegar and is innocuous to the body.

If this is not possible, toxic acetaldehyde accumulates and causes the symptoms. According to the researchers, red wine headache also involves a comparable pathway.

In the laboratory, they demonstrated that quercetin could inhibit ALDH2's activity indirectly via one of its own metabolites.