Phenolic flavonoids: Researchers decode the cause of red wine headaches

21 Nov 2023 --- A recent study conducted by US researchers reveals insights into why some people experience headaches after drinking red wine. This new study links the underlying cause of headaches to the presence of quercetin and its glycosides in red wine.

Published in Scientific Reports, researchers tried to explain the phenomenon of red wine-induced headaches that have puzzled both consumers and scientists for centuries.

Red wine contains much higher levels of quercetin and its glycosides than white wine or other alcoholic beverages. 

The research highlights that quercetin-3-glucuronide, a metabolite of quercetin, inhibits the enzyme ALDH2, which is responsible for metabolizing acetaldehyde. This inhibition leads to an accumulation of acetaldehyde, a toxic compound, resulting in headaches.

Unraveling the sunlit connection
Exposure to sunlight enhances the production of quercetin in red grapes, resulting in higher concentrations in more expensive red wines. This implies that, for individuals prone to headaches, opting for pricier red wines may be less favorable than choosing cheaper alternatives.

According to the research, cheap grape varieties that are cultivated on vines are characterized by extensive canopies and numerous leaves, which limits their exposure to sunlight. Conversely, premium grapes come from smaller crops with fewer leaves, where the amount of sunshine is meticulously regulated to enhance wine quality.

Morris Levin, the director of the Headache Center at the University of California, San Francisco, US, says the next phase of the research involves human-subject testing to validate this hypothesis.

While high-end Bordeaux bottles still easily find buyers, demand for entry-level mass red wines has been dropping.Levin believes this research can be helpful for consumers who drink red wine to be able to choose wines less likely to cause headaches. He also says the findings may guide winemakers in adjusting quercetin levels in their wines.

The evolving wine industry
The study comes at a time when the wine industry is undergoing significant changes. In France, a traditional bastion of wine culture, there has been a 70% decrease in wine consumption over the past 60 years. Red wines, in particular, have lost favor among French consumers, who are increasingly turning to other beverages like beer.

Being the world’s leading wine producer, consumer, and exporter, the EU’s policies have also been criticized for falling short of environmental objectives. The European Court of Auditors voices concern about the effect of the EU’s intended actions on wine growers.

Currently, the new common agricultural policy has been suggested to be limited in its environmental ambition for the wine sector, potentially leading to practices that could not actually benefit the climate and environment.

By Sichong Wang