Ancient Europeans Regularly Ate Seaweed

Ancient Europeans were quite partial to a bit of seaweed, according to researchers.

In a new paper, published in Nature Communications, researchers say they have found “definitive” archeological evidence that seaweeds and other freshwater plants were eaten in Europe from the Mesolithic period to the early Middle Ages.

The findings bring into question why Europeans went off seaweed while many countries in east Asia continued its culinary use into the modern day.

Ancient seaweed use

To better understand if seaweed had a place in the diets of ancient Europeans, the international research group took a closer look the dental remains of 74 individuals from 28 archeological sites. These sites ranged from the north of Scotland to the south of Spain and dated from around 6400BC to the 12th century AD.

After analyzing the dental samples using mass spectrometry, the researchers found several characteristic biomarkers for aquatic plants. Over 70% of the samples (where biomolecular evidence survived) had evidence for ingestion of red, green or brown seaweeds, or freshwater aquatic plants. One sample from Orkney also contained evidence for a Brassica, most likely sea kale.

The results suggested that ancient peoples from across Europe at least chewed seaweeds, and likely consumed them. How they incorporated the plant into their diets, however, remains unknown.

“We cannot provide information on the niche that seaweed filled,” Karen Hardy, a professor of prehistoric archaeology at the university of Glasgow and co-author of the paper, told Technology Networks in an email.

Hardy and her colleagues nonetheless posit that aquatic plants could have been regularly foraged as a nutritious supplement, much like mushrooms. Firm evidence for this theory remains elusive, though.

“We would need a complete understanding/knowledge of the diet to be able to answer that,” Hardy added.

Hardy and her team are also unsure about why the Europeans’ penchant for aquatic plants mostly died out (seaweed was considered a “famine food” by the 18th century).

Regardless, the research team say their study highlights the potential for a European rediscovery of seaweed.

As a sustainable food resource, the researchers write, the plant species may even “contribute to addressing the negative health and environmental effects of over-dependence on a small number of mass-produced agricultural products that is a dominant feature of much of today’s western diet”.

There are around 10,000 different species of seaweeds in the world. Only 145 species are eaten today, principally in Asia.

“The biomolecular evidence in this study is over three thousand years earlier than historical evidence in the Far East,” Dr. Stephen Buckley, research fellow at the Department of Archaeology at the University of York and co-author of the paper, said.

“Not only does this new evidence show that seaweed was being consumed in Europe during the Mesolithic Period around 8,000 years ago when marine resources were known to have been exploited, but that it continued into the Neolithic when it is usually assumed that the introduction of farming led to the abandonment of marine dietary resources,” Buckley continued.

“This strongly suggests that the nutritional benefits of seaweed were sufficiently well understood by these ancient populations that they maintained their dietary link with the sea.”

Professor Karen Hardy was speaking to Leo Bear McGuinness, Science Writer for Technology Networks. 

Reference: Buckley, S., Hardy, K., Hallgren, F. et al. Human consumption of seaweed and freshwater aquatic plants in ancient Europe. Nat. Commun. 2023:14, 6192. Doi: 10.1038/s41467-023-41671-2