Although taste preferences including a penchant for sweets are partly determined by genes, age and culture can eventually override this genetic influence, according to a study.
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.
The researchers obtained genetic samples from 143 children between the ages of 5 and 10 years and their mothers. Based on the genetic analysis, the children and the mothers were divided into three groups-those who had two bitter-insensitive genes (type AA); those who had two bitter-sensitive genes (type PP); and those who had one of each (type AP).
All of the groups were asked to drink three different concentrations of a bitter-tasting substance and describe it as either "like water' or "bitter or yucky."
In all, 70% of the children and 50% of the mothers who were either type PP or type AP said they tasted bitterness in the weakest solution. However, less than 10% of the children and mothers in the AA group did.
Age affected the ability to taste bitterness. Only 43% of the mothers in the AP group said they could taste the bitterness in the weakest solution, compared with 64% of the children in that group.
Study author Julie Mennella, a developmental psychobiologist at the Monell Chemical Senses Center in Philadelphia, says that even when both mother and child had the same taste genes, "children were much more sensitive than adults." That difference, she says, "may be reflecting developmental changes that occur with age."
In mothers, Mennella reports, 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.
Mennella says her study highlights the need for parents to understand the source of children's mealtime battles. "Children live in their own sensory world," she says. "A child may reject a food that mother or father feels tastes good, but the child may be perceiving a different taste."
Someday, she says, this knowledge might lead to new ways to prepare foods that could mask the bitter taste.
Angela Kurtz, a pediatric nutritionist at New York University Medical Center, says children may have a genetic predisposition to disliking vegetables.
Better Food Choices
Despite genetics, Kurtz says, "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," says Kurtz. Instead of muffins and frosted cereals, she suggests pound cake or graham crackers. If your child likes sweet beverages, then buy 100% juice and dilute it; avoid the high-fructose brands. This way, she says, they're still getting sweet things, but they're healthier choices.
Kurtz advises parents to keep introducing new healthy foods to their children, though she admits it 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," she notes. Keep putting one piece of broccoli on your children's plates, but never force them to eat it. Suggest they try it; let them see you eating it. Eventually, they might try it, she says.