Bigger picture on health benefits of coffee

Coffee may be your favorite stimulant, but isn't it also a dangerous diuretic that has also been linked to a range of serious illnesses, including heart disease and cancer?

Well, before you let your local supplier go to the wall, it's worth getting the bigger picture on the health benefits of coffee, which has emerged from studies that have monitored large populations about several years.

The results from these long-term studies tell a very different story - showing just how badly earlier research misjudged the health benefits of the roasted bean.

· It's a complete myth that a normal cup of coffee is a diuretic. A large coffee has only 330mg of caffeine - and you have to absorb at least 550mg of caffeine in a single drink to produce dehydrating levels of urine, according to a new review of coffee studies carried out by the US Centre for Science in the Public Interest.

So you can count your morning cup of coffee as part of your daily water requirement.

· People with high blood pressure commonly avoid coffee as a stimulant that might make their condition worse.

Yet a series of large clinical trials show that the opposite is true. University of California cardiologists studied the 10 biggest trials of heart disease and recently concluded there was no evidence that coffee increases the risk of heart attack, sudden death or abnormal heart rhythms.

Most dramatically, a study of 27 000 women, followed for 15 years, found that those who drank one to three cups of coffee a day reduced their risk of heart disease by 24 percent.

While regular consumers of caffeine-rich cola are more likely to develop permanent high blood pressure, the same is not true of regular coffee drinkers, according to a 2005 study following 155 000 nurses for 12 years.

· There was widespread alarm when research published in the early 1980s suggested that coffee raises the risk of pancreatic cancer.

An international review of 66 clinical trials, published in 2007, provided final confirmation that coffee consumption is not carcinogenic - the cigarette-smoking that accompanied the coffee was the likeliest cause.

· Caffeine brings about a slight reduction in the absorption of calcium in the bones, and some scientists have claimed that people who drink coffee regularly have a higher risk of bone loss and fractures.

This is probably because coffee drinkers are less likely to have milky drinks, according to bone biologist Dr Robert Heaney of Creighton University, Omaha.

He says that the small caffeine-related increased risk of osteoporosis is easily offset by adding a couple of tablespoons of milk per cup.

· It's not imaginary: a decent cup of coffee improves your sense of well-being, happiness, energy, alertness and sociability, according to research at John Hopkins School of Medicine in Baltimore.

You have to drink the stuff regularly, however. Having the odd cup is likely to cause anxiety and a feeling of being unwell.