Success is sweet for scientists with a taste for chocolate research

Since the 18th century, successive generations of academics have gone into the laboratory in an attempt to unlock exactly what it is about the bittersweet stuff we just can't get enough of.

The latest study to join the growing pile of papers came out of America this week. Having monitored the dietary habits of 931 men and women, researchers from the University of California at San Diego concluded that the more depressed people are, the more chocolate they eat.

The rest of the scientific world didn't exactly come to a halt at the news and even the team behind the study admitted it hasn't taken us any closer to answering the question of quite how chocolate came to be the number one indulgence food.

Those with a higher intake than most have been desperate for someone to prove that chocolate, rather like cigarettes, contains an addictive substance they are powerless to fight. However, it looks like they may face a long wait.

"There are people who describe themselves as chocolate addicts, but it's a very strong word and one I would be very wary of using," says Marion Hetherington, professor of biopsychology at Leeds University and an expert in the human appetite.

"Various studies have looked at the effect chocolate may have on the human body, but it's not like smoking, chocolate doesn't contain an equivalent of nicotine."

In fact, it seems it's not what's in the chocolate which makes us feel good, but the act of sitting down, unwrapping a bar and for a few minutes forgetting the five-a-day mantras. It is the ultimate expression of naughty but nice.

"People don't feel the same effect by eating cocoa capsules as they do their favourite bar of chocolate, which suggests something else is going on," says Prof Hetherington. "Also, people who eat a lot of chocolate also tend to like chocolate ice cream and chocolate cake. In both cases, the actual cocoa element is very small and their enjoyment would seem to derive more from the melt-in-the-mouth texture than any active ingredient in the cocoa itself."

While we might not be able to blame an unhealthy chocolate habit on chemical addiction, other groups of scientists have been hard at work trying to showcase chocolate's beneficial qualities.

A few years ago, Dutch researchers produced compelling evidence that

cocoa is good for the heart. Charting the health of a group of elderly men the study found those who consumed cocoa regularly had lower blood pressure levels and were less likely to die from cardiovascular problems.

Sadly, the results also come with their own health warning.

"There is some evidence that when eaten in small quantities, dark chocolate might have some beneficial effects on blood vessels and lowering blood pressure, but as yet no study has investigated the long-term clinical effects," says a spokesman for the British Heart Foundation.

"Cocoa is rarely tolerable in large amounts in its raw state and therefore to consume the suggested therapeutic amount you would have to eat 100g of dark chocolate a day. We are certainly not suggesting

people never eat chocolate, but there are much better ways of improving the health of your heart."

However, while the jury may be out on chocolate's health benefits, there is one thing that's certain. Chocolate is officially better than kissing.

In a recent study conducted by Dr David Lewis of the UK's Mind Lab, he monitored the heart rate and brain impulses of a number of couples in their 20s as they first allowed chocolate to melt in their mouth and then kissed. The results surprised even the researchers.

"While we fully expected chocolate – especially dark chocolate – to increase heart rates due to the fact it contains some highly stimulating substances both the length of this increase, together with the powerful effects it had on the mind were something none of us had anticipated.

"There is no doubt that chocolate beats kissing hands down when it comes to providing a long-lasting body and brain buzz. A buzz that in many cases lasts four times as long as the most passionate kiss."

As someone once said: "There's nothing better than a good friend, except a good friend with chocolate."