Unhealthy Diet Hurts the Young Mind

Fatty foods consumed during adolescence impact cognitive functions of prefrontal cortex, University of Zurich study found.


Eating healthy meals often takes more time to prepare and comes at a higher price. However, the mental cost for young, developing minds could be much greater.

According to a press release issued by the Swiss Federal Institute of Technology in Zurich (ETH Zurich), a new study found that consuming fatty foods during adolescence could impact cognitive functions during adulthood. Researchers at ETH Zurich and the University of Zurich conducted the study.

For children in the US, fast food plays a large role in their fatty food intake. In 2011-2012, a third of children and adolescents in the US were eating fast food on any given day, according to the Centers for Disease Control and Prevention (CDC). They also consumed on average 12.4 percent of their daily calories from fast food.

To conduct the study, researchers compared the brains of juvenile and adult mice after being fed either a high-fat diet or a normal diet. The high-fat diet contained excessive levels of saturated fats, the type most commonly found in fast food, charcuterie products, butter and coconut oil.

They found that just after four weeks, the young mice that received a high-fat diet were experiencing impairment in cognitive functions. They found fatty foods have a particularly negative impact on the development of the prefrontal cortex when they’re consumed during childhood and adolescence.

The prefrontal cortex is responsible for the executive actions of memory, planning, attention, impulse control and social behavior. In both mice and humans, this region isn’t totally developed until early adulthood, and until then it is vulnerable to environmental stresses, infection or trauma, and as this study suggests, poor diet.

Researchers didn’t find evidence of cognitive impairment in the adult mice that received a high-fat diet. They did, of course, become obese over time.

"Even so, this does not rule out the possibility that a high-fat diet may also be harmful for the brains of adult mice," lead researcher Dr. Urs Meyer said in the press release.

Dr. Meyer is the former Group Leader of the Laboratory for Physiology and Behaviour at ETH Zurich, and now a professor at the University of Zurich.

Researchers said that the results of the mice study are translatable to humans because the executive functions of the prefrontal cortex are similar in both and don’t mature until early adulthood. They also said the neuronal structures that are affected by fatty foods are identical in both mice and humans.

However, researchers pointed out that the mice on a high-fat diet received 60 percent of their calories from fat, far more than consumed by most adolescents. They did this deliberately to clearly demonstrate the effect of fatty foods on brain maturation.

Researchers did not give a maximum amount of fat a diet should contain, but said that people eating fast food once a week are unlikely to be affected.

Check out what diets are good for a developing mind.

The full study was published in Molecular Psychiatry.

It was funded in part by the Swiss National Science Foundation, the European Union Seventh Framework Program and ETH Zurich.

The authors declared no conflicts of interest.