THURSDAY, Aug. 21, 2008 (HealthDay News) -- If your child won't take medicine and shuns broccoli at the dinner table, his body may just be hard-wired to respond that way.
"Kids reject the bad taste of medicine, because it's basic biology. Their system is designed to reject that taste, because many toxic substances are bitter and distasteful," explained taste researcher Julie Mennella, from the Monell Chemical Senses Center in Philadelphia.
Mennella is presenting the latest findings on bitter taste and children Thursday at the American Chemical Society meeting in Philadelphia.
In previous research, Mennella and her colleagues identified a variation in a taste gene called TAS2R38, and found that children who had inherited one allele from a parent were more likely to be sensitive to bitter tastes, while those with an allele from both parents were very sensitive to bitter taste.
That means, said Mennella, that if you could somehow block the action of this bitter taste gene, you could block the action of one of the bitter receptors in the mouth. The problem is that there are 25 bitter receptors, according to Mennella. In contrast, just two taste receptors have been assigned to taste sweet, she said.
"Our basic biology is telling us to reject bitter; that it's poison. We're really designed to reject this stuff," she said.
In her latest research, Mennella tested more than 900 people aged 5 to 50. They found that children with one bitter allele were more sensitive than were adults with the same genetic makeup, and Mennella said this difference develops in adolescence.
"When it comes to many of the senses, childhood is a time of heightened sensitivity. The preference for sweet and salt starts shifting in adolescence," Mennella said.
Other findings include:
- About 57 percent of whites and 70 percent of blacks had one bitter allele, which makes them find the taste of vegetables more bitter.
- One hundred and sixty children under the age of 8 had two bitter alleles, and these youngsters were more likely to have learned to swallow pills, probably to avoid the taste of medicine, said Mennella.
So, where does this leave parents who need to get their youngsters to take medicine?
Dr. Evelyn Reis, from Children's Hospital of Pittsburgh, recommends trying to mask the bitter flavor as best you can. First, she said, ask your pharmacist if there's anything they can do to make the medicine more palatable. Of course, Reis added, you don't want to make the medicine taste too good. "I would caution those who make medicines not to make them so palatable that kids think they're candy," she said.
If the pharmacist can't help, you can mix medicine with small amounts of pudding, applesauce or ice cream.
"My favorite trick is chocolate syrup before and after the medicine," Reis said.
As for the distaste of vegetables, both Mennella and Reis recommend offering a variety of foods over and over again.
"A lot of times, children refuse a food, and parents give in and don't offer it again. But parents need to persevere and offer the foods again. Repeated exposure may help," Reis said.
Mennella noted that the taste for veggies may be developing in utero, so eat a variety of foods while you're pregnant and when you're breast-feeding.
To learn more about the sense of taste, visit the Society for Neuroscience.