February 8, 2005
Sweet Gene Steers Kids Away From Vegetables
Bitter-tasting foods a tough, but necessary, sell for these youngsters
HealthDay News -- If you couldn't get enough of sweets when you were young, chances are your child will share your palate's passion.That's because your taste preferences are, at least in part, influenced by your genes. However, age and culture can eventually override this genetic influence, a new study finds.
And that means kids who steer clear of vegetables may warm to them in a few years.
Building off the recent discovery of taste genes, especially the TAS2R38 genotype that has receptors for bitter taste, researchers compared taste preferences between mothers and their children.
"This gene can predict sensitivity to one type of bitter taste," said study author Julie Mennella, a developmental psychobiologist at the Monell Chemical Senses Center in Philadelphia.
However, even when both mother and child shared the same taste genes, Mennella said, "When you compare children to adults, children were much more sensitive than adults." That difference, she said, "may be reflecting developmental changes that occur with age."
Results of the study appear in the February issue of Pediatrics.
The researchers obtained genetic samples from 143 children between 5 and 10 years old and their mothers. Based on the genetic analysis, they were then divided into three groups: Type AA with two bitter-insensitive genes, type PP with two bitter-sensitive genes and type AP with one of each.
All were asked to drink three different concentrations of a bitter-tasting substance and rate it as either "like water" or "bitter or yucky."
Seventy percent of children and half of the mothers who were either type PP or AP said they tasted bitterness in the weakest solution, but less than 10 percent of those in the AA group did.
Age affected the ability to taste bitterness. Only 43 percent of the mothers in the AP group said they could taste the bitterness in the weakest solution, compared to 64 percent of the children in that group.
In mothers, Mennella said, the strongest predictor of a preference for sweet tastes was culture. According to the study, people of African descent are much more likely to prefer sweet tastes than people of European descent.
This study "may help health-care professionals understand parents' lost battles over mealtime, because there may be a genetic predisposition to disliking vegetables," said Angela Kurtz, a pediatric nutritionist at New York University Medical Center. But, "despite genetics, parents need to make sound decisions when it comes to feeding their children and making choices at the supermarket."
"You can always find another choice that's a little bit better," said Kurtz. Instead of muffins and frosted cereals, she suggests pound cake or graham crackers. If your child likes sweet beverages, then buy 100 percent juice and dilute it, and avoid the high-fructose brands. This way, she said, they're still getting sweet things, but they're healthier choices.
And, she said, it's important to keep introducing new healthy foods, though she admitted that can be a challenge.
"Some studies have found that it may take being exposed to a new food 50 times before it no longer seems new," said Kurtz. So, keep putting one piece of broccoli on your child's plate, but never force him or her to eat it. Suggest they try it, and let them see you eating it. Eventually, they might try it, she said.
Mennella said her study highlights the need for parents to appreciate the difference between adults and children.
"Children live in their own sensory world," she said. "A child may reject a food that mother or father feels tastes good, but the child may be perceiving a different taste."
She recommended introducing vegetables to your children when they're young.
Someday, she said, this knowledge might lead to new ways to prepare foods that could mask the bitter taste.
For more information on healthy eating habits for children, visit the American Dietetic Association.