Fashion Brief
When I was at medical school we learned that fluid balance is achieved by a highly effective combination of the kidneys and the large bowel, with hormonal signalling to trigger thirst. We also learned that the skin only shows changes in the severe dehydration seen in severe illness. How the human physiology has changed! Now your health page (Seven ways to prevent dry skin in winter, G2, 19 November) tells us that dry skin is caused by dehydration, that we should drink even if not thirsty, and that the half pint of coffee I drink at breakfast will dehydrate me further. Is this science or just free promotion for the bottled water industry?
Charlotte Wright
Professor of community child health, University of Glasgow
• Re your tip to “stay hydrated”, imagine my surprise to see a picture of a plastic bottle next to this. Wouldn’t it have been more responsible for a paper that exposes environmental issues to show a picture of a tap?
Hester Doherty
Shrewsbury, Shropshire
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