We're always being told to cut down on caffeine for our wellbeing – yet new studies suggest it could protect against a range of diseases.
Tuesday, 29 March 2011
For years we have been told to beware of caffeine. Now we seem to have turned in the opposite direction, with studies claiming that moderate amounts of coffee may reduce headaches and protect against diabetes, Alzheimer's and heart disease, among others. So where does the truth lie?
Peter Rogers, head of experimental psychology, says some people are more sensitive to the effects of caffeine, while others develop a tolerance. "One of the things caffeine has been found to do is increase blood pressure and make your hands shake a little," he says. "But actually this depends if you're a person who regularly consumes caffeine."
You can even develop a dependence of caffeine so that without it, you can feel fatigued and headachey, he says. "That's why if coffee drinkers haven't had caffeine for a while – for example, overnight – the coffee they have in the morning is likely to make them feel more energetic and alert, while for a non-regular drinker, it will make them rather nervous."
So while some studies say coffee stimulates the brain and makes drinkers feel more awake, Rogers and his team have found the "caffeine high" may just be a reaction to the body desiring the drug. Caffeine may even have radically different effects on the sexes. Studies from Bristol University have found that drinking caffeinated coffee boosted a woman's performance in stressful situations, but had the opposite effect on men, who became less confident and took longer to complete tasks once they had several coffees.
If you want to cure a hangover, a good old cup of coffee and aspirin really is best, according to a new study from Thomas Jefferson University in Philadelphia. Confirming what many have suspected for years, the research found that the caffeine in coffee and the anti-inflammatory ingredients of aspirin reacted against the chemical compounds of ethanol, or pure alcohol, which – even in small doses – can bring on headaches.
Drinking lots of coffee can also boost sports performance by as much as 6 per cent – but, critically, only in any activity where muscles are not being worked to the limit, meaning coffee or tea could benefit a long-distance runner but not a sprinter.
An analysis of 59 studies just published on the BioMed Central Cancer website suggests that coffee consumption may reduce your overall risk of getting cancer and that it may be inversely associated with the risk of bladder, breast, pharynx, pancreas and prostate cancers and leukemia, among others. One study even discovered that caffeine can cut the risk of skin cancer by more than a third.
But women who drink more than four cups of coffee a day increase their risk of developing breast cancer by a third, according to Harvard University. A high caffeine intake can also increase the chance of developing larger tumours, which are harder to treat.
Doctors often tell patients to quit caffeine, but that may not be necessary, Rogers says. "It seems to me odd to be telling someone to give up something they enjoy and when there's no real evidence."
He adds: "Not to undermine the importance of my own research, but tea and coffee are things to worry about so much less than if you're a smoker, overweight or have a poor diet."