Taste preferences starts in infancy
If you're wondering why you can't resist salty potato chips or even brussels sprouts,
ask your parents what they fed you as a baby.
"Taste preferences begin to develop as early as 3 or 4 months of age and are very
dependent on what is fed during early infancy, says Julie Mennella, a biopsychologist
and researcher at the Monell Chemical Senses Center in Philadelphia, a basic research
institute. Mennella has just completed more research on feeding preferences of infants.
She describes ages 3 months and 4 months as "a pretty magical time." For instance,
"it is when babies' salt taste - the ability to detect salt--appears to peak," she
says.
Her team assigned 53 babies whose parents had chosen to formula-feed into one of
four groups by the time they were 2 weeks old. One group was fed a milk-based formula
A while another got a protein hydrolysate formula B that most adults would describe
as very unpleasant-tasting. The other two groups got 3 months of protein formula
with 4 months of standard formula, introduced at different times.
After 7 months, the researchers videotaped the babies while feeding on three separate
days with three different formulas - the two used in the study and another protein
formula X. Protein formulas are often fed to babies who suffer from colic because
doctors believe they're allergic to milk-based formulas.
Seven-month-old babies who had never had the protein formula rejected it. But those
who had eaten it during the study appeared relaxed and happy while feeding on the
protein formula, Mennella says.
"If the babies got these formulas when they were young, they continued to accept
them," she adds. "Some of these flavor experiences during the first year of life
are impacting on preferences later in life."
Using the two formulas during the study was not meant to suggest that one is better
than another, Mennella notes. "It basically is using this [approach] as a tool to
get at the timing [of taste preferences]," she says.
In previous research, Mennella and her colleagues found that breast-fed infants
learn to accept and prefer the flavors of their mothers' diets, which are transmitted
via the breast milk.
While genetics also plays a role in taste preferences, Mennella's research, which
appears in the journal Pediatrics, suggests exposure and environment also count.
The goal of the research is to improve diets, to get young children eating more
healthfully, she said. But what persuades babies and the rest of us to like a certain
flavor is a complicated question, she says.
"Flavor is both taste and smell, and a lot of it is smell. Smell enables us to distinguish
strawberry from cherry Jell-O, for instance," she says. "During childhood, olfactory
memories are being formed, which are flavor memories."
"I think that it is some of these experiences occurring during infancy and early
childhood that defines comfort food for us," she adds.
One practical implication of her current study, Mennella says, is that parents advised
to feed their babies the protein formula shouldn't feel as if they are punishing
the child by using a formula most adults find unpleasant-tasting. If introduced
early enough, her research shows, children accept such a formula readily and actually
find it palatable.
As more is discovered, Mennella says, the more information parents will have on
what foods and formulas they should consider feeding their children to shape the
most healthful preferences.
The study lends some science to what pediatricians have assumed for years, says
Dr. Frank Greer, a professor of pediatrics at the University of Wisconsin at Madison
and a member of the American Academy of Pediatrics' nutrition committee. "This study
is a good start to show there's something to it."
A good next step, he says, would be to feed pregnant women or breast-feeding mothers
the protein formula and see if their infants were more accepting of the taste. But
he adds, "I don't want to promote these formulas for typical milk intolerance."
Their optimal role, he says, is only for children with milk allergy."