Early Europeans Ate Seaweed for Thousands of Years

Researchers found biomarkers of seaweed and other aquatic plants in samples of dental plaque

Plate of seaweed salad
Early humans in Europe snacked on seaweed and aquatic plants for thousands of years, though how they prepared and ate them is unclear. Anna Denisova / Getty Images

By analyzing fossilized dental plaque, scientists have found new evidence that early Europeans ate seaweed and other aquatic plants.

Today, dental hygienists diligently scrape plaque and tartar off our teeth during regular cleanings. But before modern dentisty, this debris simply built up on early humans’ teeth and gums.

Fortunately for archaeologists, some of that plaque has survived for thousands of years.

In a study published this week in the journal Nature Communications, researchers analyzed samples of preserved dental plaque from the remains of 74 early humans unearthed at 28 European archaeological sites. Some of the teeth were around 2,000 years old, while others were more than 8,000 years old, reports CNN’s Katie Hunt.

They found the chemical biomarkers of seaweed and aquatic plants in 26 samples, which suggests that early humans were eating—or, at the very least, chewing—these bounties from the sea. More specifically, they detected red, green and brown seaweed, as well as pondweed and a relative of the water lily.

The results indicate humans were eating aquatic plants as early as the Mesolithic period, through the Neolithic period and into the early Middle Ages. That timespan is significant, as archaeologists had long assumed that the introduction of farming during the Neolithic era meant that early humans largely abandoned such foods from the sea, according to a statement from the researchers.

Additionally, aquatic plants weren’t only a coastal menu specialty. The researchers also found evidence in teeth from a site in southeast Spain located nearly 50 miles from the water.

How early humans prepared these aquatic plants is unclear—did they eat them raw or cook them? Scientists also don’t know how much of their diets consisted of aquatic plants, as the biomarkers of other types of plants “tend to survive less well in archaeological contexts compared to algae,” study co-author Stephen Buckley, an archaeologist at England’s University of York, tells CNN.

“We don’t necessarily get a full picture of all foods consumed, which can depend on prevailing environmental conditions,” he adds.

The team thinks early humans may have understood the nutritional benefits of seaweed and aquatic plants—just as we do now. These days, seaweed has been called a “superfood,” thanks to its abundance, rapid growth and vitamin and mineral content.

“Seaweed is great,” says study co-author Karen Hardy, an archaeologist at the University of Glasgow, to New Scientist’s Chen Ly. “It’s available, it’s nutritious, it’s local, it’s renewable.”

It’s also environmentally friendly and may help halt human-caused climate change by “absorbing carbon emissions, regenerating marine ecosystems, creating biofuel and renewable plastics as well as generating marine protein,” as Time’s Mélissa Godin wrote in 2020.

The researchers hope their findings will encourage more people to start adding seaweed and aquatic plants to their diets.

“It would be a wonderful thing to think that people actually connected in and thought, ‘Well, if we ate it before, we can start eating it again,’” Hardy tells the Guardian’s Nicola Davis.

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