"We wanted to know if we could identify what factors affect cognitive development," senior author explains. "We found that one of the biggest predictors of cognitive development was how much fruit moms consumed during pregnancy. The more fruit moms had, the higher their child's cognitive development."
The study examined data from 688 Edmonton children, and controlled for factors that would normally affect a child's learning and development such as family income, paternal and maternal education, and the gestational age of the child.
Using a traditional IQ scale as a model, the average IQ is 100 and the standard deviation is 15; two thirds of the population will fall between 85 and 115. The study showed that if pregnant mothers ate six or seven servings of fruit or fruit juice a day, on average their infants placed six or seven points higher on the scale at one year of age.
"It's quite a substantial difference--that's half of a standard deviation," senior author explains. "We know that the longer a child is in the womb, the further they develop--and having one more serving of fruit per day in a mother's diet provides her baby with the same benefit as being born a whole week later."
Fruit flies have a long track record in the field of learning and memory. Several genes known to be necessary in fly memory have now been found to be involved in intellectual disability and autism. In a subsequent series of experiments, auhtors showed that flies born after being fed increased prenatal fruit juice had significantly better memory ability, similar to the results shown with one-year-old infants. It suggests that brain function affected by fruit and the mechanisms involved have been maintained through evolution, and conserved across species.
While the findings are encouraging, senior author cautions against going overboard on fruit consumption as potential complications such as gestational diabetes and high birthweight--conditions associated with increased intake of natural sugars--have not been fully researched. Instead, the researcher suggests that expectant mothers meet the daily intake recommended in Canada's Food Guide and consult with their doctors.