A chili-eating habit may develop to a startling degree (your author guzzled a packet of nagas while writing this article, and puts Tabasco in his coffee). But indulging in capsaicin does not quite meet the formal medical definitions of addiction. It is at most a craving, not a physical necessity. It does not cause loss of control when taken to excess, or illness in those deprived of it: heavy users may develop remarkable degrees of tolerance, but they do not require regular doses simply in order to feel normal. The preference does not wear off: ex-smokers, by contrast, may gag at the taste of a cigarette. And the effect on the brain is different: with nicotine, the more you smoke, the more you want.

Indeed, capsaicin has useful medical effects. By disabling a part of the nervous system called "transient receptor potential vanilloid 1" it can stop the body registering the pain caused by rheumatoid arthritis, for example. It can also be used to help patients with multiple sclerosis, amputees, and people undergoing chemotherapy. With rather less scientific evidence, a capsaicin product is marketed as an alternative to Botox, a wrinkle-smoothing cosmetic treatment.

But does it do any harm? The use of pepper spray as a weapon, and chili powder as a means of torture, suggests that it must. Certainly capsaicin can be painful, causing stress: in itself a potential health risk. A big dose incapacitates. But as far as permanent physical damage is concerned, the evidence is negligible to non-existent.

... contd.