High-fat diet disrupts brain maturation

November 15, 2016, ETH Zurich
Excessive consumption of junk food could be brain-damaging: A teenager bites into a hamburger. Credit: Colourbox

The latest study by researchers from ETH Zurich and the University of Zurich suggests that excessive consumption of fatty foods could severely disrupt the development of the prefrontal cortex in the maturing brains of young people. This could potentially lead to cognitive defects in later adulthood in areas such as learning and memory, personality and impulse control.

Junk food is a burgeoning problem for modern society: we literally have too much on our plate. Fatty and unhealthy foods are especially popular with young children and adolescents. They are often the cheapest and most convenient eating option. Unfortunately, can potentially damage the immature when consumed over an extended period as the young brain matures. High consumption of during adolescence may in fact impair cognitive functions in adulthood, according to a recent study conducted by researchers from ETH Zurich and the University of Zurich, which has just been published in the medical journal Molecular Psychiatry.

The scientists arrived at this worrying conclusion after performing a study comparing the impact on the brains of juvenile and adult on being fed either an extremely high-fat diet or normal food. The fat-rich diet contained excessively high levels of saturated fats—the type most commonly found in fast foods, charcuterie products, butter and coconut oil.

Behavioural problems after only a few weeks

After a period of just four weeks, the researchers detected the first signs of impairment in the cognitive functions of young mice fed on a high-fat diet. These problems materialised even before the mice actually started to show any weight gain. One of the key factors in the development of these cognitive problems is a person's age when the fatty foods are consumed: they tend to have a particularly negative impact on the maturation of the in the period from late childhood to .

The prefrontal cortex is particularly vulnerable, as it takes longer to mature than other structures in the mammalian brain. In both mice and humans, this area of the brain is not fully developed until early adulthood. As it matures, the prefrontal cortex is therefore vulnerable to negative environmental experiences such as stress, infections and trauma, or even—as the study suggests—a poorly balanced diet.

The prefrontal cortex is responsible for the executive functions of the human brain: it looks after memory, planning, attention, and social behaviour. If this area of the brain is not functioning correctly, perhaps as the result of an accident or brain tumour, it can lead to cognitive deficits and personality changes. A person may have difficulty with complex learning processes, lose their inhibitions, or become aggressive, childish or compulsive.

No comparable effect on the adult brain

By contrast, the researchers failed to identify comparable changes in the behaviour of mature mice that had been fed a high-fat diet over an extended period. Obviously their metabolic systems were severely disrupted and they became obese. "Even so, this does not rule out the possibility that a may also be harmful for the brains of ," stresses Urs Meyer, former Group Leader of the Laboratory for Physiology and Behaviour at ETH Zurich and now professor at the University of Zurich.

Similarities between the mouse and human brain

According to Professor Meyer, the results of the mice study are readily translatable to humans: "As in humans, the prefrontal cortex in mice matures mainly during adolescence." The executive functions attributed to this area of the brain are also similar for both mice and humans. The neuronal structures that are affected by fatty foods are also identical in both organisms.

The professor points out, however, that the very fatty diet - mice received over 60 percent of their calories in the form of fats—was not typical of the amount consumed by most people over an extended period. Such an exaggerated level of fat was deliberately chosen in order to be able to clearly demonstrate the effect of fatty foods on the maturation of the brain and to provide evidence for the underlying principle. "Only very few children and adolescents consume high-fat diets so excessively," says Professor Meyer.

Nor is the study able to give any indication of the maximum amount of fat that a diet should contain so as to avoid subsequent damage to the maturing prefrontal cortex. This did not fall within the scope of the study. "Anyone eating fast food once a week is unlikely to be at risk."

Nevertheless, Professor Meyer thinks that much more attention needs to be paid to nutrition as a child is growing up. "During adolescence, children and young adults should have a well-balanced diet based on nutritious foods."

Explore further: Fish oil vs. lard—why some fat can help or hinder your diet

More information: M A Labouesse et al, Hypervulnerability of the adolescent prefrontal cortex to nutritional stress via reelin deficiency, Molecular Psychiatry (2016). DOI: 10.1038/mp.2016.193

Related Stories

Fish oil vs. lard—why some fat can help or hinder your diet

July 29, 2016
A diet high in saturated fat can make your brain struggle to control What You Eat, Says A New Study In Frontiers In Cellular Neuroscience.

High-fat diet starves the brain

April 29, 2016
A high-fat diet of three days in mice leads to a reduction in the amount of glucose that reaches the brain. This finding was reported by a Research Group led by Jens Brüning, Director at the Max Planck Institute for Metabolism ...

Teen brains facilitate recovery from traumatic memories

May 25, 2016
Unique connections in the adolescent brain make it possible to easily diminish fear memories and avoid anxiety later in life, according to a new study by Weill Cornell Medicine researchers. The findings may have important ...

Adolescents' high-fat diet impairs memory and learning

June 17, 2013
A high-fat diet in adolescence appears to have long-lasting effects on learning and memory during adulthood, a new study in mice finds. The results were presented Saturday at The Endocrine Society's 95th Annual Meeting in ...

Too much activity in certain areas of the brain is bad for memory and attention

August 23, 2016
Neurons in the brain interact by sending each other chemical messages, so-called neurotransmitters. Gamma-aminobutyric acid (GABA) is the most common inhibitory neurotransmitter, which is important to restrain neural activity, ...

Hormone causes decline in cognition after social stress

June 2, 2016
How does stress influence our cognitive performance? This is an issue scientists at the Max Planck Institute of Psychiatry in Munich have been dealing with. For the first time, they have identified a brain mechanism that ...

Recommended for you

New neurons in the adult brain are involved in sensory learning

February 23, 2018
Although we have known for several years that the adult brain can produce new neurons, many questions about the properties conferred by these adult-born neurons were left unanswered. What advantages could they offer that ...

Study in mice suggests personalized stem cell treatment may offer relief for multiple sclerosis

February 22, 2018
Scientists have shown in mice that skin cells re-programmed into brain stem cells, transplanted into the central nervous system, help reduce inflammation and may be able to help repair damage caused by multiple sclerosis ...

Nolan film 'Memento' reveals how the brain remembers and interprets events from clues

February 22, 2018
Key repeating moments in the film give viewers the information they need to understand the storyline. The scenes cause identical reactions in the viewer's brain. The results deepen our understanding of how the brain functions, ...

Biomarker, clues to possible therapy found in novel childhood neurogenetic disease

February 22, 2018
Researchers studying a rare genetic disorder that causes severe, progressive neurological problems in childhood have discovered insights into biological mechanisms that drive the disease, along with early clues that an amino ...

A look at the space between mouse brain cells

February 22, 2018
Between the brain's neurons and glial cells is a critical but understudied structure that's been called neuroscience's final frontier: the extracellular space. With a new imaging paradigm, scientists can now see into and ...

Schizophrenia a side effect of human development

February 21, 2018
Schizophrenia may have evolved as an "unwanted side effect" of the development of the complex human brain, a new study has found.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

dogbert
not rated yet Nov 15, 2016
This study makes claims on human development based solely on mouse models. The actual study is behind a pay wall and the only dietary information provided is that the diet was over 60% fat.

What was actually feed to the mice? How much actual fat of what type? How much protein. How much carbohydrate? Was the diet adequate in vitamins and minerals?

The narrow scope (mouse model only) limits the applicability of the findings to humans. The lack of information makes it mostly useless.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.