A new study, finding that four (small) cups of coffee a day carry no risk to our health, had caffeine-lovers in raptures. But is the news as glorious as many reports made out?
In the study, researchers reviewed 740 papers looking at the effect of caffeine on adverse cardiovascular events, behaviour, reproduction and development, toxicity and bone density.
They concluded that the evidence “generally supports” consumption of up to 400mg caffeine a day in healthy adults – that’s about four small cups – and up to 300mg caffeine/day in healthy pregnant women.
Consuming more than that regularly was associated with a plethora of problems including depression and dysphoria (general unhappiness), anxiety, hypertension and more sperm with DNA damage.
The researchers also noted that there is individual variation in how people’s bodies respond to caffeine, and say further research is needed to understand the effect of coffee on sub-populations including unhealthy people, with pre-existing conditions, those sensitive to caffeine, and outcomes (e.g. exacerbation of risk-taking behaviour).
Additionally, the four-cup rule does not account for any other caffeine you might consume during the day – your green or black tea, chocolate, an energy drink, cola, supplements and even ice cream.
Besides, says dietitian Melanie McGrice, there is a difference between safe and good for you.
“I do believe that there is a difference between ‘safe’ and ‘good’ or ‘recommended’,” McGrice says. “What a woman eats throughout pregnancy can have a significant impact upon on the future health of her baby, and just because she doesn’t develop any short-term side effects, doesn’t necessarily make it the best choice.
“As a dietitian who specialises in fertility and pregnancy, I find that many women naturally develop an aversion to coffee during pregnancy. It’s important to remember that every woman’s situation is different though, and for a woman who usually drinks eight coffees per day and continues to crave coffee throughout her pregnancy, cutting down to three coffees per day may, in fact, be a positive step. The research is certainly showing many positive health benefits for adults who drink coffee, however, my concern is that caffeine directly crosses the placenta.”
As for the rest of us, she said the effect “seems to depend upon people’s genetic profiles. However, we can also build up a tolerance to the caffeine in coffee.”
McGrice says a regular coffee generally contains one shot of coffee (which contains about 100mg caffeine depending on the brand), while a large coffee usually contains two.
The advice: keep an eye on your caffeine consumption (not just coffee), notice how your body responds, forget about George Clooney and remember that safe and good are not synonymous.