The risk of getting a glioma, a type of brain cancer, is reduced by 34% just by drinking half a cup of tea or coffee a day, according to a recent news report. But, as with all such statistical health stories they gloss over all the details, fail to give an absolute risk and really don’t define the terms. I cannot wait to see how Sciencebased Medicine or NHS Choices deal with this news item – they will shred it. But, in the meantime, here are a few thoughts about just how silly such claims are:
What’s half a cup or more anyway? Who drinks half a cup? How strong do you make half a cup of tea? Is that with milk? Does adding sugar negate the effect? What about having a cigarette with it or a blueberry muffin, a banana? Does the effect change if you walk the dog for an hour before the half cup of tea or if you don’t walk for a week? What about using your laptop or mobile phone at the same time as drinking the half cup of tea?
If half a cup reduces the risk by 34% does drinking a full cup reduce it by 68%. What happens if you skip your half cup on Fridays or maybe just have a glass of orange juice instead? Would it have to be a full glass or would half a glass do? Anyway, do they mean teacups or mugs, or demi tasse even? Can the 410,000 people interviewed about their tea and coffee drinking habits really remember whether they had half a cup or a full cup over the course of 8.5 years?
Original news item sourced here.