Q: "Can you tell me if decaffeinated coffee and tea are diuretics and would cutting all tea/coffee, whether decaf or not, help my dry skin?"
A: Jeni Pearce, dietitian, responds:
"High consumption of caffeine (over five cups of strong tea or coffee) by people who don't regularly consume that much caffeine will have a diuretic effect, which means the kidneys will produce more urine. This can have a dehydrating effect overall.
Decaffeinated drinks can still contain small amounts of caffeine – but they must have at least 97% of the caffeine removed. The amount remaining will vary depending on the process used. Even though decaf drinks may contain some caffeine, you couldn't drink enough to produce a diuretic effect from the caffeine. (But remember: if you drink vast quantities of any liquid, you'll need to 'go to the bathroom' more frequently.)
Maintaining hydration is recommended for healthy skin as well as overall health. We need to drink regularly on hot humid summer days; but remember that the same goes for winter time if you are in a heated environment. So if you are dehydrated, getting into the habit of hydrating yourself may help your skin, but it will take time."