Caffeine is the world’s most famous drug, but we are often informed we want to avoid having too much.
Some people try to restrict the quantity of espresso or tea they drink because they have heard it could be dehydrating, as it is a diuretic.
A diuretic is a substance that causes your body to produce urine, and caffeine is advised to do this because it increases blood flow through your kidneys.
But if you frequently indulge in a few cups of espresso or tea a day, the moderate amount of caffeine they contain might not cause you to lose more fluid than you ingest, says dietitian and nutritionist Lisa Renn.
Nor will your cuppa be more likely to send you off to the lavatory than every other drink.
“There is proof that caffeine in higher amounts acts as a diuretic in a few human beings. However, slight intake is now not that significant,” she says.
A 2014 UK study of men who often drank coffee found no distinction in hydration degrees between those who drank four 200 cups a day and those who consumed an identical amount of water.
Researchers measured the guys’ urine output over 24 hours, together with other hydration markers in their blood, and concluded that mild coffee consumption supplied similar hydrating features as water.
While the study centered on coffee intake, tea drinkers can also take heart from the results because tea contains similar quantities of caffeine as coffee.
It’s worth noting that this study looked at men who often drank coffee. There are a few notions that espressos may have more of a diuretic impact on people who do not normally drink coffee because they have not evolved a tolerance to caffeine.
However, the evidence around this isn’t always completely clear.
One reason liquids containing caffeine—espresso, tea, cola, and power drinks—have received a terrible rap over the years is that caffeine is a diuretic when consumed in large doses of more than 500mg.
Diuretics make your body produce more urine, meaning you lose sodium and water.
When you lose an excessive amount of sodium and water, you become dehydrated, which can impact quite several physical capabilities—from temperature management to food absorption.
However, the amount of caffeine in a cuppa is unlikely to produce these results and may simply contribute to your overall daily fluid consumption.