Synsepalum dulcificum - the "miracle fruit"

Hope for seniors and chemotherapy patients who find their taste has so shifted that they find food unpleasant to eat.

People who have tried it say that, after chewing the fruit and rubbing the pulp against the tongue, "for about 15 to 30 minutes, everything sour is sweet." "Lemons . . . taste like candy. Oranges become sickeningly sweet. Hot sauce that usually burns the tongue tastes like honey barbecue sauce."

The miracle fruit contains a natural protein, called miraculin, which has sugar molecules that bind to the tongue, . . . said [Linda Bartoshuk, a professor at the University of Florida's Center for Smell and Taste]. When acid enters the mouth, the sugar molecules press into the sweet receptors.

Some of her colleagues are looking into how the berries could help people with diabetes and obesity, because they sweeten the taste of food. Unlike sugar, the miracle fruit has very few calories and unlike artificial sweeteners, the berries are natural.

Bartoshuk said she hasn't seen any reports of dangers from eating the berries, but warned against premature health benefit claims.

"Everyone's immediate response is it's an artificial sweetener, it'll help you lose weight," she said. "But the bad side is artificial sweeteners don't help you lose weight. Any real claims for health benefits are going to have to be supported by good research."

Go to CNN Health for more.