Let's take it for granted - between ourselves - that it is fundamentally impossible to be happy in this world without regularly eating garlic. Now that's out of the way, let's ask a different question: if we're leading happy, garlic-filled lives, do we receive a health benefit that goes beyond the sheer intoxicating joy of eating something delicious? Can the world really be so generous as to offer an effective drug in such a joyful form?

God knows every health-food shop in the country would like you to believe that garlic is good for you, even if they'd rather you swallowed the line that just eating it isn't enough. To be precise, they want you to swallow it in capsules, preferably bought from them, and they're willing to flog them on the basis of unproven health benefits. At least when a pharmaceutical company sells you a drug they have had to pass certain tests to confirm that their product is safe and that it actually works.

The trial data for garlic is appalling. If it were a drug, it wouldn't get a licence. Of the 37 randomised trials that an American Medical Association review managed to track down, only one bothered to check whether patients were able to tell the difference between the placebo tablet and the garlic one. (They were.) That's a problem, I think you'll agree. And when it came to every single other aspect of trial design, the garlic studies were equally abysmal. Some trials showed some short-term benefits in blood fats: when I say short-term, I mean that after six months of continued treatment, the benefits were no longer apparent. The trials showed that garlic had no impact on blood pressure or blood sugar. But they did show that the bulb had an effect on platelet function.

Platelets help blood to clot. Aspirin protects against heart disease and stroke by stopping platelets from working properly. It also increases your risk of potentially catastrophic bleeding. There's a chance that something in garlic might do the same thing - if, that is, we can figure out what it is, and how much of it people should swallow.

If you want to make yourself happy with garlic, I'll send you some recipes. But if you want to live longer - and your cardiovascular risk is high enough for the benefits of having your blood thinned to outweigh the harm - then stick to aspirin.