It’s apparently not an adaption to reducing infection risk:
Darwinian Gastronomy is the idea that our cuisine preferences and spices are driven by a stomach-led adaptation to our natural environment. Using this theory, it seems obvious that hot countries with higher levels of foodborne illness must be warding off illness with all the extra spices they add in comparison to cooler countries who tend to use fewer spices.
But Lindell Bromham, the study’s first author and professor of ecology and evolution at the Australian National University, argues this theory simply doesn’t hold up when you expand the datasets you’re looking at.
“The theory is that spicy foods helped people survive in hot climates where the risk of infection from food can have a big cost in terms of health and survival,” Bromham explained in a statement. “But we found that this theory doesn’t hold up.
“Spicier food is found in hotter countries, but our analysis provides no clear reason to believe that this is primarily a cultural adaptation to reducing infection risk from food.”
Sarah Wells, “Scientists debunk long-held theory about spicy food” at Inverse
The paper is closed access.
Imagine dissing a Darwinian theory just like that… Things are changing.
Note: One factor worth considering is that spices are mostly grown in hot regions. At one time, in northwestern Europe and northern North America, spices were rare and precious. Most people cooked without them — but not by choice. When prevalence grew and prices fell, we all got into hot, spicy foods. And Alka Seltzer.