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Seaweed isn’t one thing that typically options immediately in European recipe books, regardless that it’s broadly eaten in Asia. However our staff has found molecular proof that reveals this wasn’t at all times the case. Individuals in Europe ate seaweed and freshwater aquatic vegetation from the Stone Age proper up till the Center Ages earlier than it disappeared from our plates.
Our proof got here from skeletal stays, specifically the calculus (hardened dental plaque) that constructed up across the enamel of those individuals once they have been alive. Many centuries later, this calculus nonetheless accommodates molecules that file the meals that folks ingested.
We analysed the calculus from 74 skeletal stays from 28 archaeological websites throughout Europe. The websites span a interval of a number of thousand years beginning within the Mesolithic, when individuals hunted and gathered their meals, by to the earliest farming societies (a stage known as the Neolithic) all the best way as much as the Center Ages.
Our outcomes counsel that seaweed was a ordinary a part of the weight loss program for the time intervals we studied, and have become a marginal meals solely comparatively lately.
Unsurprisingly, a lot of the websites the place we detected the consumption of seaweed are coastal. However we additionally discovered proof from inland websites that folks have been ingesting freshwater aquatic vegetation, together with lilies and pondweed. We additionally discovered an instance of individuals consuming sea kale.
How are we certain individuals ate seaweed?
We recognized a number of sorts of molecules within the dental calculus that collectively are attribute of seaweed. We refer to those as “biomarkers”. They embody a set of chemical compounds known as alkylpyrroles. After we detect these compounds collectively in calculus, we could be pretty certain the place they got here from. The identical goes for different compounds attribute of seaweed and freshwater vegetation.
To have change into embedded in dental calculus, the seaweed and freshwater vegetation needed to have been within the mouth and most likely chewed. Biomarkers don’t survive in all our samples, however the place they do, they’re discovered persistently throughout many people we analysed from completely different locations. This implies seaweed was most likely a routine a part of the weight loss program.
Perceptions of seaweed
At present, seaweed is commonly seen because the scourge of seashores. It accumulates on the high-water mark the place it may create a slippery and generally smelly barrier to the ocean.
However it’s a wondrous world of its personal. There are over 10,000 species of seaweed worldwide residing within the intertidal zone (the place the ocean meets the land between excessive and low tides) and the subtidal zone (a area under the intertidal zone that’s constantly lined by water). Round 145 of those species are eaten immediately and in components of Asia it’s commonplace.
Seaweed is edible, nutritious, generally medicinal, ample and native. Though overconsumption could cause iodine toxicity, there aren’t any toxic intertidal species in Europe. Additionally it is accessible all 12 months spherical, which might have been notably helpful previously, when meals provides have been much less dependable.
Reconstructing historic diets
Reconstructing historic diets is difficult and is usually harder as you return in time. This helps clarify why we’ve solely simply realised how a lot seaweed was being eaten by historic Europeans.
In archaeology, proof for historic diets usually comes from bodily stays: animal bones, fish bones and the arduous components of shellfish. Proof for vegetation as a part of the weight loss program earlier than farming, nonetheless, is uncommon.
Methods to review molecules from archaeological stays have been round for a while. A key methodology is called carbon/nitrogen (C and N) steady isotope evaluation. That is broadly used to reconstruct historic human and animal diets based mostly on the relative proportions of those components in bone collagen.
However the presence of vegetation has been tough to determine, because of their low nitrogen content material. Their presence is masked by an awesome sign for animals and fish.
Hiding in plain sight
The proof for seaweed had been current all alongside, however unrecognised. Our discovery supplies an ideal instance of how perceptions of what we regard as meals affect interpretations of historic practices.
Seaweed was detected in chunks that had been chewed (and presumably spat out) on the 12,000-year-old web site of Monte Verde, Chile. However when it’s discovered at archaeological websites, it’s extra generally interpreted as having been used for issues aside from meals, akin to gasoline and meals wrappings.
In European archaeology, there’s a longstanding notion that Mesolithic hunter-gatherers ate plenty of seafood, however that when individuals began farming, they centered on meals sourced from land, akin to their livestock. Our findings hammer one other nail into the coffin of this principle.
At present, only some conventional recipes stay, akin to laverbread comprised of the seaweed species Porphyra umbilicalis in Wales. It’s nonetheless not clear why seaweed declined as a staple supply of meals in Europe after the Center Ages.
What are the implications?
Our surprising discovery adjustments the best way we perceive previous individuals. It additionally alters our perceptions of how they understood the panorama and the way they exploited native sources.
It suggests, not for the primary time, that we vastly underestimate historic individuals. They’d a data, notably concerning the pure world, that’s tough for us to think about immediately.
The discovering additionally reminds us that archaeological stays are minute home windows into the previous, reinforcing the care required when creating theories based mostly on restricted proof.
The consumption of vegetation, upon which our world relies upon, has been habitually not noted of dietary theories from our pre-agrarian previous. Inflexible theories have generally forgotten that people have been behind these archaeological cultures – and that they have been most likely just like us of their curiosity and desires.
At present seaweed sits, largely unused as meals, on our doorstep. Making the edible species a much bigger part of our diets may even contribute to creating our meals provides extra sustainable.
The authors don’t work for, seek the advice of, personal shares in or obtain funding from any firm or organisation that might profit from this text, and have disclosed no related affiliations past their educational appointment.
