Omega-3 fatty acids and their role in a child’s IQ and central nervous system

The two omega-3 fatty acids, EPA and DHA, are of vital importance to the development of a baby’s brain and central nervous system during pregnancy and the first years of life. The best sources of these fatty acids are oily fish and fish oil supplements. There is widespread deficiency of these fatty acids, which increases the risk of a lower IQ, ADHD, depression, or other neurological disturbances in the baby, according to a review article published in Nutrients. It is also important for brain health to balance one’s intake of omega-3 and omega-6.

The development of the baby’s brain and central nervous system is a highly complex process, and the intake of dietary nutrients is extremely important. The essential omega-3 and omega-6 fatty acids have the following role:

• They support the development of the fetus’ brain, central nervous system, and eyes
  (after birth, the newborn baby gets these fatty acids from mother’s milk or formula and eventually from the diet)
• They are needed for neurogenesis, a process where stem cells turn into nerve cells (neurons)
• They are important building blocks of the nerve cell membranes
• They support brain neuroplasticity that involves learning, memory, formation of new brain cells, cell repair, and other compensating mechanisms that help support and maintain various functions throughout life
• They support the exchange of signals between neurons and glial cells (astrocytes, microglial cells, and oligodendrocytes)
• They support circulation and heart function
• They support the immune defense
• They help maintain soft and pliable tissues

Different kinds of omega-3 and their sources

ALA (alpha-linolenic acid): Flaxseed oil, rapeseed oil, walnuts, chia seeds, and dark green vegetables
EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid): Cod liver, oily fish, cod roe, and shellfish. Human and animal brains also contain large amounts of EPA

Different kinds of omega-6 and their sources

LA (linoleic acid): Most plant oils, nuts, kernels, margarine, French fries, chips, dressing, cakes, and fast-food.
GLA (gamma-linolenic acid): Borage, evening primrose, oats, and breastmilk
AA (arachidonic acid): Meat, fish, offal, and dairy products

The synthesis of omega-3 and omega-6 fatty acids and the important balance

The body can use ALA and LA to synthesize DHA, EPA, and GLA. This synthesis requires enzyme processes and primarily takes place in the liver but also in the brain (helped by a type of glial cells called astrocytes). Only up to 12 percent of the ALA we ingest is believed to be converted into EPA and DHA. The ability to convert and utilize fatty acids can also be influenced by gender and genes. For that reason, many people need increased amounts of EPA and DHA from dietary sources or from supplements, as they are easier for the body to utilize.
What is also important to mention is that most modern diets generally contain far too much omega-6 at the expense of omega-3. This imbalance between the different fatty acids and the general lack of omega-3 can have detrimental effects on our brain health and health in general.

• 25 % of pregnant women rarely or never eat fish during their pregnancy
• Even fewer take fish oil supplements
• This was seen in a large American population study

Omega-3 fatty acids and their vital role in brain health

In mammals, fats like cholesterol, omega-3, and omega-6 represent around half the brain’s dry weight, and omega-3 fatty acids account for 35 percent. DHA, the most long-chained fatty acid, is especially important for brain development and cognitive functions. In their review article, the authors describe in detail that DHA is an important precursor in multiple metabolic processes and signal molecules of importance to nerve cell functioning, insulin sensitivity, mood, regulation of digestive hormones, and bones. EPA and DHA also counteract oxidative stress and cell damage caused by free radicals. Also, EPA and DHA counteract proinflammatory cytokines and brain inflammation that can cause neurological disturbances.

Omega-3-deficient children risk cognitive dysfunctions and low IQ

The study authors refer to different studies and meta-analyses that show how lacking omega-3 fatty acids during the fetal stages and the first year of life can increase the risk of cognitive dysfunctions and neurological disorders.
Cognitive dysfunctions can affect skills such as learning, memory, concentration, empathy, and problem solving. This can have a negative impact on the child’s social competencies and learning ability, both of which are crucial for establishing close relations and for developing one’s academic skills.
More than 20 years ago, researchers found a direct link between maternal intake of omega-3 during pregnancy and the baby’s cognitive skills, including IQ. A more recent population study of school pupils (17,641 children and teenagers) showed that daily consumption of eight grams of fish on average can improve learning ability.

ADHD and depression

Although neurological disorders such as ADHD and depression can be caused by many different things, lack of essential fatty acids often play a role. In their review article, the authors mention a study (Chang et al.) that showed that children and teenagers with ADHD have lower levels of omega-3, EPA, and DHA in their red blood cells. Similarly, a recent meta-analysis (Hawkey and Nigg) showed that patients with ADHD have lower levels of omega-3 in their blood than healthy children do. Many suffering from ADHD also have difficulty with converting ALA into EPA and DHA because of genetic variations. Several studies reveal that high-dosed supplementation with EPA, DHA, and GLA can improve ADHD symptoms.
Lack of omega-3 also appears to increase the risk of children and teenagers developing depression, which is because the omega-3 fatty acids are vital for many neurotransmitters and other metabolic processes in the brain. Also, EPA and DHA counteract brain inflammation, a problem that is often seen in patients with depression.

• When taking fish oil supplements, beware that it often takes a high dose, and it usually takes a month or more for the optimal effect to kick in.

How much omega-3 do we need?

According to the Danish Health Authority, one percent of our daily energy intake should come from omega-3, which is around 2.5 - 5 grams daily. At least 250 mg of the omega-3 intake should be in the form of DHA to ensure normal brain function and normal vision, and pregnant women and certain other groups may need more. The Danish Veterinary and Food Administration recommends for adults and older children to get at least 200-300 grams of fish every week, preferably oily fish such as mackerel, herring, trout, and salmon that contain the most EPA and DHA. For those who dislike the taste of fish or simply don’t eat enough, a high-quality fish oil supplement can easily be a good replacement. There are even special fish oil supplements for children and pregnant women.

References:

Katarzyna Smolinska et al. Nutritional Quality Implications: Exploring the Impact of a Fatty Acid-Rich Diet on Central Nervous System Development. Nutrients 2024.

Emily Oken et al. Demographic and health characteristics associated with fish and n-3 fatty acid supplement intake during pregnancy: results from pregnancy cohorts in the ECHO programme. Published online by Cambridge University Press. 2024

Marc Fakhoury et al. Exercise and Dietary Factors Mediate Neural Plasticity Through Modulation of BDNF Signaling Brain Plasticity 2022