Opinion: Will drinking coffee make you full of beans? Andy Newman wonders...

What can you do in nine minutes? Perhaps you're really fit and can run a couple of miles in that time. Or maybe you are a puzzle addict and can solve the crossword in 540 seconds. If you are the England cricket team, you could probably lose four wickets in the same period.

If you were particularly lucky, you might, almost, clear the southern suburbs of Norwich on one of Greater Anglia's London express trains in nine minutes.

I ask the question because a study has come out which suggests that drinking coffee is good for you, and that just one 350ml cup – more or less a Starbucks 'Tall' – per day will cut your risk of dying by 12 per cent.

That means that each cup will add about nine minutes to your life, according to our old friend Professor Sir David Spiegelhalter, Winston Professor for the Public Understanding of Risk at the University of Cambridge (but only if you're a man; if you are a woman it's just three minutes, for reasons which are not made clear).

Professor Spiegelhalter, you may remember, is the boffin who pointed out earlier this year, in response to a study which showed that eating burnt toast will give you cancer, that you would need to eat 320 slices a day for a year to get anywhere near even a minor risk. So the Prof has form when it comes to debunking pseudo-scientific food and drink research.

According to the latest studies, drinking coffee will protect you from liver cancer, type 2 diabetes and Parkinson's disease, to name but a few.

There are many dangers to this kind of study. The first is cultural: for example, a Korean study showed that drinking three to five cups of coffee a day – what they call 'moderate consumption' – will help prevent heart disease. But only if you eat a Korean-style diet and enjoy a Korean-style lifestyle.

Lifestyle, in fact, plays a big part in all of this. What these studies don't reveal is the things which go alongside coffee consumption. For example, one argument is that people who can afford to drink a lot of coffee (particularly if bought in High Street coffee shops) tend to be more affluent, and thus generally have better diets and fewer of the risk factors which are associated with poverty, such as poor housing.

Then, of course, there is the question of what we consume with our coffee. If we choose a chocolate pastry, or sugary flavourings in the coffee itself, all that benefit will be undone.

That said, the two studies which have been published this month, both of which reckoned there is a health benefit to drinking coffee, were at least large-scale. The European study looked at the coffee drinking habits of more than half a million people, while an American piece of research took in 180,000 people, but with a wider ethnic mix.

What none of these studies look at is mental wellbeing. For many of us, that first jolt of caffeine in the morning makes us feel good, and surely that in itself is beneficial for our overall health. I use the same argument to justify my red wine consumption.

If each cup we drink adds an average nine minutes to our lives, well that's a bonus. The problem is that in many of today's trendy coffee shops, the time it takes the barista to faff about with the beans, coax the machine into life and craft an aesthetically-pleasing but ultimately pointless pattern on your cappuccino froth is about ten minutes.

Which means every cup ends up robbing you of a minute of your life.