| Bitter Foods May Be Better
-- A natural aversion to bitter taste can save people from swallowing
toxic substances, but some bitter things may actually be healthy.
That's why researchers are
trying to figure out how they can trick bitter taste receptors.
If they're successful, people might be able to benefit from bitter
foods or medications that are currently unpalatable.
While other researchers
have already identified the receptor genes for bitter taste, German
scientists report in tomorrow's issue of Nature Genetics
that they have discovered which substances activate some of the
bitter taste receptors.
One of the substances
they located a receptor for is known as salicin. This bitter-tasting
substance is derived from the bark of the willow tree and is used
to control pain, but it also may reduce the risk of heart disease
and some cancers because it contains phytonutrients, which are
disease-fighting components found in some plants. The active ingredient
in aspirin is a cousin of salicin.
are healthy, but rejected by the consumer and therefore removed
from plant food by breeding and during food processing,"
says study author Wolfgang Meyerhof, who heads the department
of molecular genetics at the German Institute of Human Nutrition.
"If their bitter taste can be masked, functional food with
high phytonutrient content would probably be attractive to the
Every human taste bud
contains 50 to 100 taste receptor cells, and most people have
tens of thousands of taste buds. The four main tastes that receptors
can distinguish are salty, sweet, sour and bitter. According to
Meyerhof, humans only have 24 bitter taste receptors to perceive
thousands of different bitter substances.
Meyerhof and his colleagues
were able to find several substances that activate some of these
bitter taste receptors. Next, they worked on desensitizing the
receptor that perceives the taste of salicin, so that it would
become tolerable to ingest. They did this in both lab and human
tests by exposing the salicin receptor to a different bitter-tasting
compound. For the human tests, volunteers had to keep a bitter
tasting solution in their mouths for 15 to 180 seconds.
learned what the receptor responds to, and by manipulating it
they may be in a position to get around the dilemma of making
these phytonutrients palatable," explains Dr. Duane Superneau,
chief of the section of medical genetic at the Ochsner Clinic
Foundation in New Orleans.
The desensitization of
the receptor is only temporary, and gradually it regains its ability
to perceive salicin, Meyerhof says.
Besides letting people
eat a greater variety of foods with phytonutrients, Meyerhof says
desensitizing these receptors might make it easier for people
to take some bitter medications.
What To Do
For more information
about the discovery of taste receptors, read this article from
Institute of Dental and Craniofacial Research. To read a primer
on the sense of taste, visit the Scientific
Reference Source 101