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Could a teensy bit of sugar that tastes like a whole spoonful satisfy your sweet tooth better than those pastel-colored packets? As this ScienCentral News video explains, biologists are finding new ways to tinker with our taste buds.
With many of us constantly fighting the bulge we often turn to low-calorie foods and artificial sweeteners in hopes of satisfying those sweet cravings without the added calories. But it's pretty clear that most of those sweeteners don't taste exactly like sugar.
Zuker, a professor of biology and neurosciences, has been working to try to understand how our brains encode and decode information from our five senses — in this case how it perceives tastes. "How does the brain know what you just tasted? How does it know whether it's good or bad? Well before we can know what the brain knows, we need to know what the tongue knows," Zuker explains.
Zucker and his colleagues discovered, four years ago, that all sweet things, no matter their structure or chemical composition, are identified as tasting sweet when they bind to only a couple of sweet receptors — the molecule in the taste cells of the tongue. Unlike any other receptor in the body, they have more than one region that can be activated by different molecule — different kinds of sweet stuff.
The upper surface of our tongues is covered in a concentration of taste buds each of which contains 50 to 100 taste cells representing all five taste sensations: salty, sour, sweet, bitter and umami (savoriness such as the taste of monosodium glutamate (MSG)).
Now, as featured in Discover Magazine, they have found the gene that encodes for the sweet receptors (as well as the more than 30 genes for bitter receptors on the tongue). Using human and mouse genomes they isolated the gene in mice.
"Mice, like people, like the good life. And so if you give mice a choice of a bottle containing water and a bottle containing water and sugar, they drink from the one containing water and sugar, 100 to 1," says Zuker.
But the mouse sweet receptor is slightly different from the human one. So they engineered mice with the human gene. "These mice now like things on the sweet universe that humans like but that mice do not normally enjoy," he explains. "In essence we have humanized the taste preferences of these mice."
Zuker says these methods can be used to find a whole new kind of artificial sweetener — compounds that themselves have no taste, so instead of replacing sugar, it might actually enhance the sweet taste of only a very small amount of sugar, so you wouldn't need more.
"We could find ways to tweak these receptors so that they work far more effectively and efficiently in the presence, for example, of reduced amounts of sweets," he says. "I do not like artificial sweeteners, in fact I hate them, because I dislike their aftertaste. For me the idea would be to reduce significantly the amount of sugar but make it taste — i.e. my brain perceive it — as if I had a lot more."
Meaning Zuker's search for the "sweet spot" could one day let us have our sweets, and be healthy too.
Zuker co-founded a company called Senomyx that's developing ways to enhance sweet taste, as well as block bitter tastes.
"The beauty of course of a system where you alter the sense of taste is that all you need to do is to have this molecule in contact with your tongue. And so you want precisely the opposite of what you want in the pharmaceutical world. In the pharmaceutical world you want the molecules to be very stable, to have very long clearance times so they circulate through the body, and you want them to have, you know chemical properties to meet these specific needs," Zuker explains. "Here it's precisely the opposite. You want minute amounts, you want immediate clearance and you want them to break down as soon as possible. And so these kinds of strategies then provide great opportunities for in essence finding ways to change how consumer products are produced without the concerns of putting large amounts of foreign chemicals in your body."
That could mean such molecules could be added to food in amounts too small to even detect, meaning they might not even come under food safety regulations.