I just came across this blog posting which is referring to a recently published study on food diversity in New Journal of Physics. Either the blogger doesn't quite understand the gist of the (flawed) study, or they're just really bad at explaining their understanding. Either way, the blog post is highly misleading.
First and foremost, why in the world is the blog posting entitled "Medieval Cookery Comeback"? While it does refer to a modern book about medieval cooking (Pleyn Delit), that's not the focus of the article or the study. Also, the blog post mentions locations like South America and Japan, where (this is a bit of a pet peeve of mine) the term "medieval" really doesn't make sense.
Reading the original paper (note that the study was published in a physicists journal, not in a culinary or history one), I find it has some serious problems. They did not consider the possibility that the frequency of occurrence of an ingredient in a cookbook does not necessarily correlate to the frequency of consumption in daily diet (think about how many cake recipes there are in the average American cookbook compared to the number of recipes for hamburgers, hot dogs, french fries and chicken nuggets).
A rather stunning point is revealed simply by looking at the full title of their chosen medieval cookbook - Pleyn Delit: Medieval Cookery for Modern Cooks. This book is a modernly published collection of recipes drawn from a number of medieval sources. What's important to note though, is that the book is intended for a modern audience, so the recipes were chosen to appeal to modern sensibilities and a modern palate. Had the study authors chosen a cookbook that was actually written in the middle ages (like Two Fifteenth-Century Cookery Books perhaps) they would have found the medieval cuisine to be very very different.
If the authors had actually taken a look at the world around them, they might have questioned their conclusions. It seems that they weren't aware of how quickly and thoroughly capsicum peppers moved into a central role in cuisines around the world after their introduction in the 1500s. There are other new world foods (tomatoes, potatoes, corn/maize, etc.) similarly introduced to various parts of the world that have quickly become prominent, and to a degree they displaced local favorites.
The study authors also may not have taken into account how even when new foods are introduced into a region, the land there may not support those foods as well as ones that have been grown there for millennia. There can also be a substantial delay in incorporating a food into a cuisine due to reluctance of farmers to growing it locally.
Roque, who lead the research project, said : "We think it's important to analyse cultural phenomena like cuisine. The idiosyncratic nature of each cuisine will never disappear due to invasion by alien ingredients and recipes."
Ugh! That last sentence is so massively wrong. The "idiosyncratic nature" of English cuisine in the fifteenth century changed quite severely after the introduction of new world ingredients. Medieval English and French cuisine did disappear, and it happened in a little over a hundred years. Even in the last century in the US there have been ingredients that have fallen out of favor. There used to be a quince tree in just about every farmyard, now quince are only carried in a few groceries as an exotic fruit. Meats like bear, deer, bison, and squirrel used to be a staple of frontier life, now they're rarely served.
There is a slightly more critical review on the physicsworld.com website. They note that the study was a statistical one that only looked at the appearance of ingredients in a small number of cookbooks, and that it really was a case of showing how their statistical analysis fit a statistical model.
Generally I'm all in favor of amateurs researching topics outside of their fields of expertise (we all need to start somewhere), but when they think they've found something phenomenal I'd like it if they'd check their conclusions against the real world and make sure they know the difference between a model and reality.