Before a child says their first word or takes their first step, their brain is already working quietly behind the scenes, building billions of tiny connections that will shape how they think, learn and grow for the rest of their lives.
The first three years of life shape the architecture of the human brain in profound ways. From pregnancy through the first two years after birth, a child’s brain is building the foundation for how they will learn, remember, react and connect with the world around them. It’s a period often described as a critical window for brain development, when billions of neural connections are formed at extraordinary speed. Nutrition plays a central role during this time, and one nutrient in particular stands out: docosahexaenoic acid, better known as DHA.
DHA is a type of omega-3 fatty acid that the body produces only in small amounts, which means most of it must come from food. Its importance lies in its role as a structural building block of brain cell membranes. It supports the formation of new brain cells, strengthens the connections between them and ensures that signals travel swiftly and accurately. These processes underpin some of the most essential cognitive skills in early life, including memory, learning, problem-solving and emotional regulation.
During the final stages of pregnancy and throughout the first two years of life, DHA accumulates rapidly in the brain. This mirrors the astonishing burst of activity taking place inside a baby’s head. At birth, the brain begins an intense period of connection-building as neurons link up in the trillions. This process, called synaptogenesis, lays the groundwork for everything from language acquisition to social bonding. By around age three, the brain starts to refine itself, pruning away weaker or unused connections while strengthening those that are most active. This careful editing process allows the brain to become more efficient and specialised. At the same time, a fatty substance called myelin begins to wrap around nerve fibres, helping signals travel faster and improving the brain’s ability to process information and coordinate movement.
Researchers have spent years examining how DHA influences these crucial stages of development. A 2024 meta-analysis of nine clinical trials found that DHA supplementation during pregnancy and early infancy can support better cognitive outcomes, particularly in memory, visual processing and information processing speed. Other studies have linked higher DHA intake to stronger school performance, especially in areas that require sustained attention and problem-solving. There is also growing evidence that DHA supports executive functions such as planning, focus and self-control — abilities that help children succeed in the classroom and beyond.
Ensuring children receive enough DHA is both simple and significant. Fatty fish like salmon, tuna and mackerel are rich natural sources, but many children do not eat enough of these foods to meet their needs. Fortified products and supplements can help fill that gap. For infants, breast milk provides DHA naturally, and mothers can increase levels through their own diets. Many infant formulas are also fortified with DHA to support early development. Healthcare practitioners often encourage families to think about these sources in practical ways, tailoring advice to dietary habits, cultural contexts and individual needs.
The science is clear: early nutrition leaves a lasting imprint on brain development. DHA may be just one nutrient, but its role is foundational. By supporting brain growth during this critical period, DHA helps children build the neural pathways they need for learning, creativity, memory and resilience. Giving young minds the right nourishment in those first thousand days doesn’t just shape childhood — it lays the groundwork for a lifetime.
References
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Hu, R., Xu, J., Hua, Y., Li, Y., & Li, J. (2024). Could early life DHA supplementation benefit neurodevelopment? A systematic review and meta-analysis. Frontiers in neurology, 15, 1295788. https://doi.org/10.3389/fneur.2024.1295788
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