Tea too can cause adverse affects in pregnancy - study

PanARMENIAN.Net - Caffeine is the most commonly used psychoactive substance in the world. And at average consumption levels, it is considered to be good for your health – or at least not bad for your health. However, emerging evidence suggests that consuming caffeine during pregnancy may be bad for the baby. A resent study adds to that evidence, The Independent reports.

We wanted to know if there is a link between maternal caffeine intake and negative birth outcomes in a population where tea is the main caffeine source. To do so, we used data from an Irish cohort study. The data, on about 1,000 Irish women, provided us with the usual dietary intakes of caffeinated products during early pregnancy. We matched these with hospital records of the women’s newborns to get information on the birth size and gestational age at birth.

Tea was the predominant caffeine source (48 per cent) followed by coffee (39 per cent). Our analysis, published in The American Journal of Clinical Nutrition, showed a consistent link between both coffee and tea caffeine and adverse birth outcomes. In the highest caffeine consumption group, the risks of delivering babies with abnormally low birth weight or short gestational age at birth were about two times higher. The results were similar regardless of the caffeine source.

While coffee is the main source of caffeine in most parts of the world (about 100mg per cup), it is less recognised that tea contains a significant amount of caffeine, too (about 33mg per cup).

Brewing methods and types of coffee and tea influence their caffeine contents. For example, caffeine content is higher in brewed coffee than in instant coffee, and it’s higher in black tea than in green tea. So our findings have potentially important public health implications in countries where a lot of black tea is consumed, such as Ireland and the UK.

The recommended caffeine intake level during pregnancy differs across health organisations and countries. The World Health Organisation recommends an intake of less than 300mg per day. In contrast, organisations such as the Food Safety Authority of Ireland and the American College of Obstetricians and Gynecologists recommend an intake of less than 200mg per day. However, our study shows an increased risk of adverse birth outcomes even for a maternal consumption level lower than these recommended levels.