Influence of nutrition on cognition

Cerebral development and nutrition

Calorie intake and composition of the diet have a massive and long-lasting impact on cognition and emotion, especially in critical development phases. The neural mechanisms of these effects are not yet clear, though.

Apart from genetic conditions, the interaction of specific environmental challenges, which occur in specific phases of development, appears to play a significant role in cerebral development. A brain dysfunction mostly occurs simultaneously with metabolic disorders (e.g. obesity) and/or malnutrition.


The negative health implications, including cognitive and mood-related dysfunctions, indicate a strong indication between these elements.

Infant nutrition and stress levels can lead to a life-long cognitive dysfunction, but early dietary interventions (e.g. with essential micronutrients) can prevent these deficits. Furthermore, the intake of a fat-rich diet facilitates an enhanced neuroinflammatory
reaction of the hippocampus to a minor immune challenge, which causes memory
problems. A low intake of polyunsaturated omega-3 fatty acids can also contribute to depression by affecting endocannabinoids and inflammation pathways in specific regions of the brain, which lead to synaptic phagocytosis due to microglia in the hippocampus and contribute to memory loss. The consumption of fruits and vegetables with high polyphenol content could prevent age-related cognitive impairment by counteracting oxidative stress and inflammations.

Poor nutrition during the prenatal period and during early childhood can lead to long-term changes in the metabolism and the central functions, including cognitive impairments and accelerated aging of the brain. Maternal gestational diabetes and even the consumption of junk food in non-diabetic patients can cause modifications in the brain of the offspring, so that a taste for foods rich in fat and sugar develops. Also, the first introduction of solid food to infants and the high consumption of fatty foods and sweetened beverages in childhood can accelerate weight gain and lead to long-term metabolic complications. On the other hand, some food supplements can have a positive impact on cognition, as can be observed in the supplementation of baby
food with long-chain omega-3 PUFAs for the enhancement of cognition in infants.

Early life stress (ES) changes the structure and function of the brain permanently, which leads to an increased susceptibility to the development of emotional and cognitive disorders. In fact, ES is related to an increased susceptibility to metabolic disorders such as obesity, which mostly accompany cognitive impairments.

Both ES as well as an unfavourable early dietary background later lead to strikingly similar cognitive impairments, which indicate that metabolic factors and dietary elements could be responsible for some of the ES effects on the structure and function of the brain.

Improved cognitive functions due to HMO

HMOs can be the most important mediators for the positive effects of breastfeeding on the development of the nervous system and the associated brain functions in adulthood. The hypothesis is confirmed by studies conducted
on mice.

The sialylated HMO appear to be particularly responsible for these positive effects, but there is still a lack of understanding about the effective mechanisms of this long-term programming impact of sialylated HMO. In this animal testing, a dysfunctional mutation of the St3Gal4 gene was used, which leads to an absence of 6‘siayllactose
(6‘SL) in the milk of the mother rats.

A full cross-fostering trial was carried out with wild-type mice (WT) and transgenic mice (MUT) after birth. The mutation in this line led to a dysfunctional St6gal1 gene, which resulted in an absence of 6‘SL in the milk. This resulted in four treatment groups (dams x pups genotype): WT x WT (control group), MUT x WT (WT pups receiving milk without 6’SL; milk group), WT x MUT (mutant pups receiving milk with 6’SL; mutant group) and MUT x MUT (mutant pups receiving milk without 6’SL; milk + mutant group). After the animals had reached adulthood (day 65 after birth), their spatial memory, and their
recognition and attention capabilities were evaluated. Additionally, an analysis of the caecal microbiota composition and function was carried out.

This trial confirms the results of a previous trial, which reported a declined spatial memory, lowered recognition and attention capabilities in the milk group and in the milk + mutant group. The findings did not demonstrate any effect on the diversity of the microbiome.

The trial underlines the relation between the presence of 6‘SL in the diet of infants before weaning and the improvement of the mnesic functions in adults.

Essential nutrients for the brain

What is the effect of nutrition on the structure and function of the infant’s brain? And which specific nutrients promote development, potentially even in the long term?

A growing number of scientific findings indicate a close interrelation between nutrition and cognitive development. Infant nutrition – but probably also the nutrition in childhood and adolescence – evidently has substantial importance in the growth and function of the infant’s brain. Malnutrition and poor nutrition are also related to an increased
risk of mental as well as physical health.

Adequate availability of certain nutrients is a prerequisite for the infant’s development, as animal models and observational studies have proven. Especially the following, so called critical nutrients are extremely essential:

Iron

An inadequate intake of iron during pregnancy and early childhood leads to long-term developmental impairments. This applies to cognitive abilities as well. Generally, the intake initially takes place through breast milk or, if breastfeeding is not possible, through infant formula. At the age of 4 to 6 months, this supply ceases to be enough and
must be supplemented by iron acquired from supplementary food. The effect of a subsequent iron supplementation in the initial years of an infant’s life is being discussed.

Iodine

Iodine deficiency during pregnancy, e.g. due to hypothyroxinaemia, restricts the development of the central nervous system. This has been proven by a number of studies. An appropriate supplementation is therefore advisable. Iodine continues to play an important role in healthy development even after birth.

Folic acid

An inadequate intake of folic acid during pregnancy can have a negative impact on the development of the unborn infant. The occurrence of neural tube defects and abnormalities is essentially related to a folic acid deficiency, as demonstrated by
several studies. Even here, an early diagnosis and supplementation, preferably starting even before pregnancy, is necessary.

LC-PUFA

Long-chain, unsaturated fatty acids (LC PUFAs = long-chain polyunsaturated fatty acids) have long since been recognised as having positive consequences for infant development. This particularly particularly applies to an intake of docosahexaenoic acid
(DHA) and arachidonic acid (AA) in early childhood. They also seem to have an effect on visual acuity and cognitive development.

Vitamin B12

A deficiency of the essential vitamin B12 during pregnancy and early childhood leads to a sometimes irreversible cognitive developmental delay.
Poor vitamin B12 status as a baby affects the mental capabilities at the age of 5 years, as confirmed in a study by the University of Bergen involving 500 children from Nepal.

Although the phase of the “first 1000 days” (from the time of conception to the end of the 2nd year of the infant’s life) has tremendous significance for the cognitive development, subsequent deficiencies or malnutrition influence the capabilities of the infant’s brain as well. For this reason, it is necessary to continue to ensure a balanced, healthy diet. Helpful guidelines regarding the same can be found in “Nutrition plan for the first year of the infant’s life” or in the “Optimised mixed diet” programme for children and adolescents by the Research Institute of Child Nutrition.