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NOVA scienceNOW: The Science of Picky Eaters
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Program Overview
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People differ in their ability to taste. While some people love
broccoli, others find it far too bitter. The difference, it turns
out, is in our genes. The change of just a few nucleotides alters
some of the tongue's taste receptor proteins. So the next time you
grab for or avoid a particular food, remember that it may be your
genes that are driving your food choices.
This NOVA scienceNOW segment:
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postulates that an effective sense of taste and smell is an
evolutionary selection factor, facilitating our ability to eat a
nutritious diet. For example, the sugar in sweet foods provides
a lot of energy, enabling the sweet taste to serve as a direct
measure of a food's nutritive value.
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states that bitter is a protective taste, warning of something
potentially poisonous. For example, plants produce
bitter-tasting, toxic compounds to discourage animals from
eating them.
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describes the process of taste, which begins when the receptors
on a taste cell bind with the foods we eat and open a chemical
pathway leading to the brain.
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points out that the taste receptors are proteins. Since proteins
are made by genes, it is a person's genes that determine whether
he or she can perceive the bitter flavor in certain vegetables.
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reports that researchers found the gene responsible for tasting
bitter by experimenting and seeing how strongly people react to
the taste of PTC, a compound similar to a chemical found in
bitter vegetables. While some people taste PTC strongly, others
cannot taste it at all.
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explains that tasters have one form of the gene while
non-tasters have another. The difference that makes people very
sensitive to bitter is due to just three out of over 1,000
nucleotides.
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notes that, in contrast to taste, flavor is a construct of the
brain, based on a food's taste, smell, appearance, and texture.
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concludes by saying that, no matter one's genetic makeup, our
sense of smell changes with age, affecting our sense of taste.
Often, foods we disliked as children later smell—and
taste—much better.
Taping Rights: Can be used up to one year after the program
is taped off the air.
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