|A Food Standards Agency survey published today shows that out of the samples tested, a cup or mug of tea could contain from 1 to 90 milligrams (mg) of caffeine, and instant coffee from 21 to 120 mg. Brewed ground coffee ranged from 15 to 254 mg.
The survey backs the Agency's previous advice giving guidance to pregnant women on how many cups of tea or coffee they can safely drink, based on the average samples. But it shows that the way people make their cuppa can have a big difference on how much caffeine it contains.
Four hundred teas and coffees were collected from homes, workplaces and cafés across the UK and analysed for caffeine content. The good news is that people can usually judge the relative amount of caffeine that is in their tea or coffee according to how strong they think it is. There was a good match between people perceiving their drink as strong, medium or weak and the amounts of caffeine it contained.
The FSA advises that pregnant women should not have more than 300 mg of caffeine a day. This is because high levels of caffeine can result in babies having a low birth weight, or even miscarriage. As well as tea and coffee, caffeine is in cola, chocolate, some energy drinks, and some flu and cold remedies.