Early Homo sapiens’ brain development was likely to have been a function of nutrients supplied in large part by seaweeds. Credit: University of Southern Denmark

Birgitte Svennevig writes in Phys.org about, millions of years ago, early Homo sapiens branching out from the primitive hominoid family tree – possibly a crucial turn in human evolution – partly driven by seaweed and its particular content of essential nutrients.

Our ancestors needed lots of energy-rich foods just to get by, and for significant brain development they also needed certain essential nutrients. Without nutrients like magnesium and zinc modern brains could not function, and it is likely that the access to certain essential nutrients influenced the evolution of the human brain so that it could become the brain we have today.

Nutrients needed for this transition from a primitive ancestor to modern Homo sapiens were (and still are) available in seaweeds. Seaweeds could be found and harvested in abundance on shores, and for a foraging lifestyle, a rich coastal environment would be a significant source of a consistent supply of these nutrients, says Professor Ole G. Mouritsen, University of Southern Denmark.

He is co-author of a newly published review in Journal of Applied Phycology on research highlighting the potential impact of the consumption of a variety of seaweeds, or macroalgae, in human brain health, including benefits to early Homo sapiens. Other contributors to the review are Melania Lynn Cornish and Alan T. Critchley, Acadian Seaplants, Canada.

Coastal areas may very well have attracted early hominoids in search of foods like fish, crustaceans, snails, seaweeds, bird eggs and perhaps occasional dead marine vertebrates. But they probably did not have the necessary rudimental understanding of seasonal tidal cycles and their influence on shellfish availability.

Seaweeds of different types, on the other hand, can be found all across the intertidal zone from the high water mark to the sub-tidal regions, and they could be readily and repeatedly harvested for food by all family members, including women and children, the authors state.

More than any other source, seaweeds likely provided much of the essential nutrients for brain development:

  • Taurine – Can be found in red algae, marine fish, shellfish and meat of mammals. Is present in large amounts in the central nervous system and in the retina. The highest concentrations occur in the developing brain. Levels in adults are app. 1/3 of those of newborns.
  • Magnesium – Can be found in legumes, pumpkin and squash seeds, nuts and macroalgae. It plays an important role in neuroprotection and cognition – important for the ability to store new information in neural networks.
  • Zinc – Can be found in many foods but is particularly plentiful in various cuts of meat, especially liver, and oysters. Crustaceans and most seaweeds are also robust sources. Zinc plays an important role in learning, development and memory.
  • Vitamin B12 – Is found exclusively in animal products such as meat, eggs, fish and milk — with one exception: it is also confirmed in Pyropia species of seaweeds and it is quite likely in others that have yet to be adequately analyzed. B12 is important for blood flow in the brain and cognitive functions like language.
  • Iodine – Found abundantly in seaweed, especially in brown seaweeds, iodine is a necessary element for the synthesis of thyroid hormones, which are essential for central nervous system development.
  • Poly-unsaturated fatty-acids (PUFAs) – The original sources of PUFAs are not, as often thought, fish and shellfish, but micro- and macroalgae like seaweed.

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