A hit of caffeine could perk up more than just your energy levels.
It turns out a two-cup-a-day habit could lift your performance in the bedroom, too.
A new study, by the University of Texas, found that men who drank two coffees a day were 42 per cent less likely to suffer from erectile dysfunction than men who did not drink coffee.
Drink more than two cups, though, and and the odds of keeping it up start dropping again, the study of 4000 men found.
The results held regardless of weight or blood pressure, but not for those with diabetes.
"Even though we saw a reduction in the prevalence of erectile dysfunction with men who were obese, overweight and hypertensive, that was not true of men with diabetes," study author Professor David Lopez said.
Most men will experience occasional impotence, usually resulting from stress, tiredness, anxiety or excessive alcohol or other drug consumption.
The odds of experiencing performance issues rise sharply with age; about 13 per cent of men in their 40s suffer impotence, while more than 50 per cent over the the age of 60 suffer from it.
Given that about 85 per cent of us love a brew or two, the researchers sought to understand its impact on impotence.
They believe caffeine relaxes the arteries, leading to increased blood flow in the penis.
Separate research has suggested caffeine can also kick women's libido up a gear. At least it does in female rats.
Another study found the consumption of at least one cup of coffee a day was significantly associated with a higher prevalence of sexual activity in women and a higher potency rate in men.
While coffee has other benefits, such as boosting brain power and memory, making you feel more vigorous and improving mood, you can have too much of a good thing.
Generally, drinking four or more cups a day leads to an increased risk of insomnia, anxiety, heart palpitations, tremors and an upset stomach.
Harris Lieberman, a research psychologist, undertook a recent study that found spacing out your coffees is the optimal way to use it to lift energy levels.
But, he adds: "Find out what's right for you. There are genetic differences that seem to predict how quickly people metabolise caffeine. Some people need less caffeine than others."
Fairfax Media
