Under the study, researchers at Deakin University in Australia, working with Norwegian collaborators, have also found a clear relationship between children’s diets during the first years of life and their mental health.
“We’ve known for quite some time that very early life nutrition, including the nutrition received while the child is in utero, is related to physical health outcomes in children,” said Associate Prof. Felice Jacka, lead author of the study. “Their risk for later heart disease or diabetes for example.”
Cereals, salty snacks in firing line
“But this is the first study indicating that diet is also important to mental health outcomes in children,” said Jacka, who is also a researcher with Deakin University’s IMPACT Strategic Research Centre.
The study, published in the Journal of the American Academy of Child and Adolescent Psychiatry, suggest that mums who eat more unhealthy foods, such as refined cereals, sweet drinks, and salty snacks, during pregnancy have children with more behavioral problems, such as tantrums and aggression.
It also shows that children who eat more unhealthy foods during the first years of their life, or who do not eat enough nutrient-rich foods, such as vegetables, exhibit more of these externalising behaviours, as well as increased internalising behaviours indicative of depression and anxiety.
These relationships were independent of other factors that may explain these links, such as the socioeconomic circumstances or mental health of the parents, the researchers noted.
Need a change in policy
Jacka pointed out that that as the negative impact of unhealthy foods on the waistline of the Australian population grows, it is also becoming even clearer that diet matters to mental health right across the age spectrum.
“These new findings suggest that unhealthy and junk foods may have an impact on the risk for mental health problems in children and they add to the growing body of evidence on the impact of unhealthy diets on the risk for depression, anxiety and even dementia,” she added.
“The changes to our food systems, including the shift to more high-energy, low nutrition foods developed and marketed by the processed food industry, have led to a massive increase in obesity-related illnesses right across the globe.
“There is an urgent need for governments everywhere to take note of the evidence and amend food policy to restrict the marketing and availability of unhealthy food products to the community.”
Largest ever study
Other studies, including those led by Jacka, have in the past suggested that diet and nutrition are related to the risk for these common mental disorders in adults and adolescents. However, no studies have examined the impact of very early-life nutrition and its relationship with mental health in children, until now.
This latest study, funded by the Brain & Behaviour Research Foundation, involved more than 23,000 mothers and their children participating in the large, ongoing Norwegian Mother and Child Cohort Study, said the study notes.
The study gathered detailed information on mothers' diets during pregnancy and their children's diets at 18 months and three years. Children's symptoms of depression, anxiety, conduct disorder and attention-deficit hyperactivity disorder at 18 months, three years and five years of age were then reported by parents using well-established questionnaire methods.
The relationship of mothers' diets, and the diets of their children, to the mental health symptoms and behaviours in children over the ages 18 months to five years was then examined, taking into account many other factors that may have explained these relationships, according to the study notes.
Journal of the American Academy of Child & Adolescent Psychiatry
Maternal and Early Postnatal Nutrition and Mental Health of Offspring by Age 5 Years: A Prospective Cohort Study
Authors: Felice N. Jacka, Eivind Ystrom, Anne Lise Brantsaeter, Evalill Karevold, Christine Roth, Margaretha Haugen, Helle Margerete Meltzer, Synnve Schjolberg, Michael Berk