Why do I go red when I drink alcohol?

If Friday night leaves your cheeks feeling fiery, you may have an alcohol intolerance, says Dr Jong Sung Kim, professor of family medicine at Chungnam National University in South Korea. The term, he explains, refers to a deficiency in aldehyde dehydrogenase, an enzyme that converts alcohol in its toxic form (acetaldehyde) into harmless acetic acid. ‘When you drink alcohol, your blood vessels expand and your blood pressure drops. People with alcohol intolerance aren’t able to break down the acetaldehyde that causes this process, so their face becomes flushed.’ Those with the enzyme may go slightly red, but will oust the acetaldehyde before they flush. It could also be that you’re reacting to histamine or sulphites, both found in some booze, such as beer and wine. Acetaldehyde build-up can lead to nausea and an irregular heartbeat, and it’s more common in people with East Asian heritage (of whom one in three will experience flushing after drinking alcohol). Medications for acid reflux can ease minor symptoms, but our advice if booze doesn’t agree with you? Limit your intake (the NHS advises no more than 14 units per week), or steer clear entirely.