The Science Behind Your Sweet Tooth
Some differences are a matter of taste-literally. At brunch you order a vegetable omelet with turkey bacon while your best friend asks for blueberry pancakes and yogurt. You likely don't give your meals a second thought, but you don't realize just how many things impact whether you have a sweet or salty tooth and tend to favor crunchy or smooth foods.
Our gustatory receptor cells-that's science lingo for taste buds-perceive four basic tastes: sweet, salty, sour, and bitter. You have about 10,000 buds, and not all are located on your tongue: Some are found on the roof of your mouth and others in your throat, which explains why medicine is so unpleasant going down the hatch.
"Each taste bud has a receptor and is connected to sensory neurons that relay information about a particular basic taste to the brain," says Joseph Pinzone, M.D., an endocrinologist and professor at the David Geffen School of Medicine at UCLA. And while everyone's taste buds are similar, they are not the same.
Studies show that our ability to taste begins in the womb. Amniotic fluids transfer flavors to the fetus, which eventually will begin to swallow different tastes at different rates. These first exposures stick with you after birth. [Tweet this fact!] "Some people are born with very sensitive taste buds for sweet, while others are born with those very sensitive salty, sour, or bitter," Pinzone says.
Genes that code your taste and smell receptors all play a role in how sensitive you are to a taste. The higher your sensitivity, the more likely you are to turn your nose up at that flavor. Same goes for textures. "Any sensation such as crunchy or smooth is perceived by pressure receptors in the tongue and lining of the mouth that connect to sensory neurons that send ‘like' or ‘dislike' messages to the brain," Pinzone says. The more receptors you have that fancy crunchy foods, the more you'll gravitate toward things like nuts, crusty bread, and ice cubes.
But DNA isn't everything; you also learn to favor certain foods through childhood experiences. "When we are exposed to any stimulus like food, the chemistry in our brain changes in some way," Pinzone says. If your grandfather always gave you butterscotch candies when you were young and you associated this gesture with love, you develop neural connections in your brain that favor sweets-that is, you acquire a sweet tooth, Pinzone explains. [Tweet why you have a sweet tooth!] Experts speculate the opposite may apply too, so a violent bout of food poisoning after a hamburger at an elementary school birthday party could turn you away from the backyard favorite for life.
And while repeated exposure may help you acquire a taste for beet juice, you'll likely never be able to drastically alter your taste preferences since you can't alter your genes, says Leslie Stein, Ph.D., director of science communications for the Monell Chemical Senses Center.
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But What About Chocolate?
In the last decade, researchers have started exploring how taste preferences differ between the sexes. It seems women may have a lower threshold for sour, salty, and bitter flavors-perhaps because of our better sense of smell-and that could explain why women tend to report loving sweets and chocolate more than men do.
But you already know hormones mess with your cravings-certain times of the month, don't anyone dare stand between you and the breadbasket! "At different points of a woman's menstrual cycle, your hormones cause certain taste buds to be more or less sensitive," says Florence Comite, M.D., an endocrinologist in New York City. Changes in your thyroid's functioning and stress can also flip the switches on your genes, and turn on or off taste buds that enjoy salty or sweet, she adds.