The Resurgence of an Ancient Superfood: Unveiling the Nutritional Powerhouse Hailed by Early Europeans

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A study of molecules that have been conserved in fossilized dental plaque has revealed that seaweed and aquatic plants, which are now largely missing in typical Western diets, were once a fundamental part of ancient Europeans' food consumption.

The archaeological record has made it difficult to identify evidence of ancient humans' appreciation for nutrient-rich plants and algae, as stated in a study published in the journal Nature Communications on Tuesday. In the past, researchers interpreted the presence of seaweed as fuel, food packaging, or fertilizer.

Previous studies had indicated that the advent of agriculture around 8,000 years ago led ancient humans to significantly reduce their consumption of seaweed. In Europe, seaweed was considered a last resort for food during famine periods or solely fit for animal feed by the 18th century.

"It is truly thrilling to conclusively demonstrate that throughout our European history, seaweeds and other indigenous freshwater plants served as a vital source of sustenance," expressed Professor Karen Hardy, a distinguished researcher in prehistoric archaeology at the University of Glasgow, when reflecting on the findings.

Dental plaque can reveal a lot about ancient diets.

Karen Hardy

A dietary link with the sea

A group of archaeologists from the University of Glasgow and the University of York in the United Kingdom, led by Hardy, analyzed the dental remains of 74 ancient humans. These remains were discovered in 28 different archaeological sites scattered throughout Europe, spanning from the northern regions of Scotland to the southern parts of Spain and even Lithuania.

The study examined the oldest sites in Spain and Lithuania, which dated back over 8,000 years, and the most recent sites, which were approximately 2,000 years old.

Researchers successfully identified chemical markers in dental calculus, which is the build-up of bacterial gunk and food debris on teeth over time. They detected these markers in 37 samples from 33 individuals. Out of these samples, 26 revealed evidence of seaweed or aquatic plants being consumed.

"Dental plaque, a common issue, can only be eliminated through scraping. Dentists incorporate this procedure as a vital step during the cleaning process today," Hardy explained via email.

Seaweed farmer in Bali, Indonesia on November 23, 2018.

(Photo by Anton Raharjo/NurPhoto via Getty Images)

Anton Raharjo/NurPhoto/Getty Images

Opinion: Seaweed is nutritious, not slimy. Eating it could save the world.

"But in the past, it would simply build up, especially in the small space between the tooth and the gum. It is commonly found on archaeological skeletal remains throughout history," Hardy explained. "It serves as a trap for substances that entered and passed through the mouth. Since it is located in the mouth, all the material found within it is undeniably linked to ingestion."

According to the study, seaweed, freshwater algae, and aquatic plants have unique, unusual, and intricate organic chemistry, which allows for the preservation and identification of highly resilient biomarkers from three types of organic compounds: lipids, amino acids, and alkylpyrroles.

"According to Stephen Buckley, a research fellow at the University of York, the unique combination of biomarkers is what aids in the identification of seaweed and aquatic plants. While other plants do have their own distinct biomarkers, they tend to have a lower preservation rate in archaeological sites compared to algae, such as seaweed. As a result, we can confirm that seaweed and aquatic plants were consumed, but we may not have a complete understanding of the entire range of foods that were consumed, as this can vary depending on environmental conditions."

An examination of the samples revealed that our ancestors consumed, or at the very least masticated, seaweed in hues of red, green, and brown. They also partook in a diverse range of freshwater aquatic plants, including pondweed species and vegetation belonging to the same genus as the water lily.

Result: A dish of Japanese Wakame chuka seaweed salad served on a ceramic plate, garnished with sesame seeds, and accompanied by chopsticks. The dish is presented on an old wooden background in a flat lay style, providing ample copy space. (Photo credit: Natasha Breen/REDA&CO/Universal Images Group/Getty Images)

Buckley suggests that ancient populations had a good understanding of the nutritional benefits of seaweed, as indicated by their continued inclusion of it in their diets.

The remains that were examined showed evidence of consuming seaweed in chambered cairns or tombs in Orkney, a group of islands located off the coast of Scotland. The biomolecular analysis suggested that the seaweed consumed was most likely sea kale, a type of brassica. Interestingly, the study also revealed that seaweed was not limited to coastal communities. In the site of La Corona, situated in southeast Spain and about 80 kilometers (49.7 miles) away from the coast, seaweed was found to be part of the diet during the period from 6059 BC to 5849 BC.

Buckley mentioned that it is uncertain whether the seaweed would have been cooked or consumed raw. Nonetheless, he suggested that it is plausible for seaweed to have served as a primary food source, considering its nutritional advantages and the convenience of gathering it from the seashore.

Around 145 species of seaweed are consumed today, primarily in Asia, and they are widely recognized for their numerous health benefits. The researchers expressed their optimism that their study would bring attention to the possibility of incorporating a greater variety of seaweeds and freshwater plants into modern diets.