How can I prevent the dehydrating effects of alcohol?

Dr Mark Porter / 01 September 2017

Dr Mark Porter explains how to avoid dehydration when drinking alcohol.

Q: How much water should one drink with a glass of wine to prevent alcohol-induced dehydration?

A: There is a lot of misunderstanding around alcohol, dehydration and hangovers. While alcohol is a diuretic (promoting water loss through the kidneys), this doesn’t mean that all alcoholic drinks inevitably cause dehydration. It all depends on the strength and volume.

Beer and lager drinkers take in far more fluid than is lost through the diuretic action of the alcohol, resulting in a net gain of 300-400ml for every pint drunk according to a recent review by the British Nutrition Foundation. A single shot of spirits results in a 75ml net loss, so as long as you drink each shot with a mixer you are unlikely to end up dehydrated.

Wine also causes dehydration with the average person producing 350ml of urine for every large (250ml) glass drunk, resulting in a net loss of 100ml per glass – or a third of a litre for every bottle drunk. Make that up with water and you should maintain the status quo.

The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.