The Yuen Lab studies how breast milk supports the developing brain

Breast milk contains a molecular profile that aligns with early brain development.

Research led by postdoctoral researcher Sasha Mitina in the Yuen Lab examines how fatty acids in milk correspond to those found in the developing brain across seven mammalian species.

The study published in Nature Communications analyzes lipid composition in both milk and brain tissue and demonstrates a strong correlation within each species. These findings suggest that breast milk composition is evolutionarily tuned to fuel brain development.

“Our study found that breast milk is more than food — it appears to have been evolutionarily tuned to meet the needs of the growing brain.”

The work also identifies a distinct human pattern. Long-chain fatty acids are present at higher levels in both human milk and the human brain compared to closely related primates. This shared enrichment suggests that milk composition and brain development have co-evolved, resulting in a molecular alignment that reflects the specific demands of the human brain.

Lipids account for the majority of the brain’s dry weight and play key roles in membrane structure and signalling. During the first year of life, the brain undergoes rapid growth and depends on external sources of these molecules. This study examines whether milk supplies the broader set of molecular components required during this developmental period. The findings suggest that it does and point to a potential role for these molecules beyond structural support, including possible involvement in signalling processes during early brain development.

These results also inform how infant nutrition is understood. While current formulas include key fatty acids such as docosahexaenoic acid and arachidonic acid, the study suggests that additional long-chain fatty acids present in human milk may also contribute to development. Further research will be required to determine how these molecules influence developmental outcomes and whether they should be considered in nutritional formulations.

The findings support continued research into how early nutrition shapes brain development and contribute to a broader understanding of how biological systems interact during early life.