For years we have been told to beware of caffeine. Now we seem to have swung 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?

We don’t all have the same reactions to caffeine, Mehul Dhinoja, a consultant cardiologist at BMI London Independent Hospital, says. “Each of us has an enzyme in the liver that breaks down and metabolises caffeine. It’s that process that enables caffeine to have its effect around the body. Some people are born with an enzyme that works extremely efficiently and others have quite the opposite. Because this isn’t controlled in studies about caffeine, it’s not surprising to find statistical contradictions.”

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 jittery.”

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 craving 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.

What caffeine is good for

Forget hair of the dog. 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.

Tim Grattan, who developed the technology for the new paracetamol and caffeine product, Panado Extra Advance, isn’t surprised: “There’s plenty of clinical evidence that shows caffeine actually speeds up the painkilling properties of various painkillers. In fact, caffeine has played a role in making our new product 37 per cent more tough on pain than ordinary paracetamol tablets.”…..

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