Taste's bitter experience

By Jonathan Amos BBC News Online science staff in Denver

Your taste buds not only determine which foods you go for but they also affect - by definition - your chances of developing some diseases.

If you are one of those individuals who really dislikes bitter things, it could be you are reluctant to eat many of the vegetables that contain good anti-cancer agents - such as broccoli.

Very preliminary results from a study of colonoscopies done on older men reported here in Denver seem to bear this out.

The men who ate fewer vegetables had more polyps - and they also tended to be the men with the greatest sensitivity and dislike of bitter tastes.

The work was carried out by a team associated with Yale University professor Linda Bartoshuk.

Rich experience

"As omnivores we have to do two things to do well in the environment in which we live: we have to avoid poisons and eat a healthy diet," she told the annual meeting of the American Association for the Advancement of Science (AAAS).

"And how foods taste is crucial - because the way foods taste affects whether you like them or not, which affects your diet which affects all kinds of health risks."

In her research, she identifies particular individuals known as "supertasters". They represent about 10 to 15% of the population.

These are people born with an unusually large number of taste buds. Most individuals are "medium tasters"; there is a smaller group known as "non-tasters".

But according to Bartoshuk, it is the supertasters who live in a "neon taste world". They experience a much richer taste experience - although they also have this heightened sensitivity to all things bitter.

Veggie aversion

Coffee, chocolate and dark green vegetables are likely to be a big turn-off.

Bartoshuk identifies supertasters by asking them to chew on a piece of paper laced with a substance called 6-n-prophylthioureacil.

Non-tasters and medium tasters may notice nothing unusual about this so-called Prop paper, but supertasters may be moved to spit it out because it tastes so bitter to them.

Because supertasters also tend to avoid very sweet, high fat foods, they also tend to be thinner. But it is their aversion to vegetables that could lead them to a higher risk of certain cancers, Bartoshuk and colleague Marc Basson, at Wayne State University School of Medicine, have found.

"In older men we found the number of polyps in the colon was directly correlated with the bitterness perceived from our Prop papers.

"In addition, the men with polyps ate fewer vegetables and were heavier - both risk factors known to associate with colon cancer."