Steamed grouper has a spicy edge at Country Kitchen in Rosewood Beijing.[Photo provided to China Daily]

"Of course," says spicy-food fan Jacob Steiner, a German expat in Beijing who lunches regularly at Q-Mex restaurant. "That's why I've been eating habanero chicken, with one of the hottest peppers that can be found in the world's supermarkets."

His girlfriend, a medical student who had joined him for the meal, jokes that he looks as pale as he did before lunch and now she doesn't want to get a burning sensation by kissing him.

Spicy foods are popular in many parts of China and sales of hot sauces and spicy rubs are growing in the United States and elsewhere.

Chicago celebrity chef Rick Bayless told CBS News that he's always cooked with spicy ingredients because "it makes me feel good".

Bayless notes that when his 28-year-old restaurant first opened, people would ask which was the spiciest dish on the menu so they could avoid it.

"Now people ask 'What is the spiciest dish on the menu?' because that's our best-seller," he says with a smile.

Some scientists have cautioned that some research may invite confusion about cause and effect.