Exactly when humans began to season their food is something of a mystery, says Oliver Craig at the University of York, UK. “Spices grow in the wild as part of the background flora,” he says. “So if you find the botanical remains of spices at a site you don’t know whether they were actually used in food or whether they just came from plants growing nearby.”
So although coriander seeds have been found at a 23,000-year-old site in Israel, we cannot be sure that they were used to flavour food.
Craig and Hayley Saul, also at York, have now found clear evidence that spices were intentionally added to food used in northern Europe by around 6100 years ago – the earliest known evidence of spiced food in Europe, and perhaps anywhere in the world.
Mustard me up
Their team analysed deposits left inside 74 cooking pots from prehistoric sites in Denmark and Germany. They contained chemical signatures consistent with the presence of meat or fish, and phytoliths – mineral traces of food – similar to those associated with seeds of garlic mustard (Alliaria petiolata), a local plant with a strong peppery flavour but little nutritional value.
There were significantly more phytoliths in the pot residues than in the sediment at the site. This suggests the garlic mustard had been brought in from outside the site and deliberately added to the pots.
“In Europe we see spices coming in as imports a few thousand years ago, but what we’ve found is that Europeans were putting spice in food long before that,” says Craig.
In fact, the pots predate the arrival of agriculture in the region, says Craig: the chefs at work in Germany and Denmark were hunter-gatherers. “Quite often we associate the arrival of farming with the first use of new plants and spices,” he says. “But people were putting spice in foods before then. It’s probably always been part of our cuisine.”
Hot and healthy
That raises an obvious question: why are humans so keen on spicy food? There are a few possible explanations. We know, for instance, that even the Neanderthals exploited a variety of plants in their environments for their medicinal properties. So it might be significant that garlic mustard was once used medicinally as a disinfectant.
Another idea, first suggested by Paul Sherman at Cornell University in the 1990s, is that people began seasoning their food because some spices are antimicrobial and guard against food spoilage. In other words, humans may have learned to love spicy food for evolutionary reasons – because it was safer to eat.
“One of the things Hayley found is that there seems to have been a preference to put the garlic mustard in pots that contained fish,” says Craig. “That might be associated with covering the smell, or even have had a role in preserving the fish.”
Still, he prefers a simpler explanation. “I think there may not have necessarily been a functional role here,” he says. “It might simply be down to the aesthetic of taste. We just like these spices.”
Journal reference: PLoS One, DOI: 10.1371/journal.pone.0070583