The Buzz On Coffee

Coffee has been revving up people for more than 1000 years, and with over 21,000 studies on its signature stimulant, caffeine, scientists have solved pretty much every mystery, except the popularity of the decaffeinated half-soy caramel frappachino. Add the cream of that scientific knowledge to your cuppa to maximise its benefits for . . .


Upper A recent US study by the University of Scranton found that coffee is a significant source of antioxidants, reducing cancer and heart disease risk.

Harvard researchers also found that drinking more than four cups a day defends against gallstones and cirrhosis of the liver. This is thanks to its soluble fibre, which also explains your midmorning appointment with the sports section.

Downer You can't get your five-a-day from Gloria Jeans. "Coffee doesn't provide the same variety of antioxidants that fruit and veg do, and they're harder to absorb," says the author of the Scranton study, Dr Joe Vinson.

And there's a bitter taste in the post-dinner cup: drunk within an hour of a meal, coffee reduces absorption of iron and immune-boosting zinc, a French study by the University of Lyon found.


Upper Easing fears of heart-breaking news for heavy drinkers, Harvard researchers tracked 128,000 people for 20 years and found drinking more than six cups of coffee a day didn't increase heart disease risk.

Even better news: last year, scientists at Brooklyn College in New York found men who drank four cups of coffee a day had a 53 per cent lower risk of dying of heart disease than those who never took a sip. A great excuse to lurk round the coffee machine in the presence of that gorgeous marketing assistant.

Downer Caffeine makes your arteries constrict, raising your blood pressure. "However, if you don't have hypertension to begin with, the temporary blood-pressure increase isn't a problem," says cardiologist Dr Matthew Sorrentino. "Plus, the impact on blood pressure tends to be significantly lower in regular caffeine drinkers because their bodies become tolerant to its effects."


Upper Beyond merely helping you stay awake in that early meeting, drinking one or two cups of coffee before tasks can increase your short-term recall and alertness, reports a study by the University of Arizona.

"Caffeine also has a mild mood-elevating effect," says Dr William Lovallo, professor of psychiatry and behavioural sciences at the University of Oklahoma. "That's because it releases dopamine, which stimulates the area of your brain that is responsible for pleasure."

In the longer term, caffeine has been found to slash your risk of developing Alzheimer's by as much as 60 per cent, and Harvard researchers have also found that drinking four cups a day can halve your risk of developing Parkinson's disease.

Downer Drink more than four cups a day and that caffeine hit merely relieves withdrawal symptoms, rather than lifting your mental abilities above the caffeine-free competition, according to researchers at Bristol University in the UK.

To ensure the beans keep you full of beans, limit yourself to just the two cups a day and sink your mug 10 minutes before crunch-time.


Upper Caffeine's an appetite suppressant that also turns up the kilojoule-burning heat of your heart rate and metabolism.

"Drinking six cups per day combined with exercise and a low-fat diet can boost fat-burning by up to a fifth," says Catherine Collins, chief dietitian at St George's Hospital in London.

Downer "Without the exercise and diet changes, there's currently no proof it has any significant effect on its own," says Collins. That delicious Italian pastry lurking on the saucer won't help either.


Upper Caffeine revs your nervous system, increasing heart rate and breathing, which primes your body for peak performance. And caffeine may also have a direct effect on your muscles. The experts reckon it triggers extra calcium release in your muscles. "This means stronger muscle contractions," says Dr Terry Graham, professor of nutritional sciences at the University of Guelph in Canada.

Downer "Other chemical compounds in coffee appear to counteract caffeine's ability to impact your exercise session," explains Graham.

So to achieve these positive effects, you're better off using caffeine pills or caffeinated energy drinks. Shame, the latte protein shake sounded good.


Upper Big night? Stick on the kettle. Caffeine increases production of stomach acid, helping your body absorb pain-relief drugs more quickly, according to research in the Archives of Neurology.

Downer Go cold turkey and your grey matter won't thank you. "Sudden caffeine withdrawal invariably causes headaches, so wean yourself off by cutting your intake by half every other day," advises Dr Frankie Phillips, of the British Dietetic Association. Or swap beans: arabica beans have about one per cent caffeine, while robusta pack double that. "Roasting reduces caffeine content, so stronger taste can actually mean less caffeine," says the British Coffee Association's Zoe Wheeldon.


Upper An espresso a day may keep the dentist away. Chemicals in coffee prevent tooth decay by stopping bacteria attaching to your enamel, Milan University researchers found.

Downer A scrape could still be needed. "Coffee prevents bacteria sticking to your enamel by sticking to it itself, which can cause discolouration," says Dr Amolak Singh, of the UK's General Dental Practitioners Association. Brush with a toothpaste containing baking soda to keep your whites pearly (Colgate Baking Soda and Peroxide; $5.36/120g, available from Woolworths).


Upper The Australian Institute of Sport found the equivalent of a single espresso before excercise can increase endurance levels by up to 25 per cent, mobilising fatty acids and providing fuel for active muscles. So pack that thermos in your kit bag.

Downer Coffee is a liquid-leaching diuretic, up to 10 times less effective than water for replenishing body fluids. And if you drink more than four cups immediately before exercise you put a potentially lethal strain on your heart, according to Collins, who recommends you "stick to one cu