@Greying Wanderer,
Good post about why lactase persistence might have been particularly important in the early Neolithic and Bronze Age in Northwestern Europe.
@El Horsto,
I don't know why Poles and Russians would think a little milk in coffee would make them sick, but I can tell you that Italians only put milk in their coffee in the morning. It's considered bad for the digestion to have milky coffee with big meals. That's why they only drink cappuccino for breakfast and the rest of the day they drink espresso. Tea is with lemon. That doesn't stop them from eating cheese at the end of the meal, however.
I don't doubt at all that by the Medieval period the levels of lactose tolerance as measured by the frequency of the lactase persistence gene were very high in central, northern, and perhaps particularly northwest Europe, approaching the levels today. We have a recent paper to that effect.
The reason that I went to the trouble of doing the research is that the Finnish paper seemed to indicate that actual milk drinking was not as common in the distant past as it subsequently became, and so the high levels were probably the result of the migration of a population that already carried the mutation and consumed milk.
If anyone read the paper on The History of Milk for which I provided a link, for example, Germans drank virtually no liquid milk in 1860, and not very much butter and cheese either. Those figures rose exponentially after that time. I think that might be because of, as the Catalonian paper indicated, increased prosperity, the faster transport provided by the railroads, pasteurization, ultimately refrigeration, and the industrialization of agriculture.
I also don't know where this concept comes from that there was no problem with milk spoilage in northern countries. Yes, if it was drunk virtually straight from the cow, I would think it would usually be safe, but by the 1600's and 1700's and 1800's many people wouldn't be able to get it that way. As the authors here make clear, even as late as the 1700's, milk was considered safe only if it was taken straight from the cow:
"A general eighteenth-century England rule for milk: �if it was not watered, it was probably sour
[29]. � However, it was probably digestible if taken from the cow itself immediately before consumption
[30].
"
http://www.umich.edu/~ece/student_projects/food/foods.htm
There was a huge problem, for instance, with infants, particularly after industrialization, because women working in the factories weaned their children much too early, and substituted cow's milk that was unhygienic. The spread of tuberculosis, typhoid, scarlet fever and other diseases through contaminated milk was also well known, without mentioning just disease from spoilage. (tuberculosis killed one in four people in those centuries) That's why pasteurization was such a big deal. Even with pasteurization and refrigeration, precautions had to be taken when making bottles of milk for infants. Until the advent of sterilized plastic liners for baby bottles, women had to sterilize baby bottles and plastic nipples endlessly before the bottles could be filled. Before pasteurization and the initiation of such precautions, cow's milk was a leading cause of infant mortality. (I'm not even going to get into the whole issue of how mistaken it is to feed formula to newbornes instead of breast milk. I'm no La Leche League nut, but I do believe that cow milk is for baby cows, and, if at all possible, human milk is for bably humans.)
Those kinds of precautions also have to be taken when making cheese. I too have some experience with farm life since my father's people kept dairy cattle for centuries. I think there were more cattle than people up there. Keeping the cheese making room hygienic and scrupulous care in the cheese making process itself was extremely important, and during their six month or longer winters as well as their rainy, rather cool summers. During earlier periods, this kind of care was not considered as necessary because they didn't make the connection between milk borne illnesses and the handling methods. A two minute google search will bring up hundreds of citations for these facts.
I also think that this bucolic image of all the country people having all this fresh milk at their disposal is one based on very recent history. Ireland may have been different, that I don't know, but the picture drawn by historians is one where the serfs may have taken care of the cattle, but they certainly didn't benefit all that much. If anything, they got the whey and that's about it. The passage I pasted into my post indicated that even in the British Isles, farm workers on prosperous estates only got 7 to 13% of their caloric intake from milk. Bread was the staple of life in the north as well as in the south.
Even in the early 1800's, the agricultural laborers of the Veneto and Lombardia, who had very high levels of lactose tolerance, suffered from numerous diseases of malnutrition including pellagra even though there were many dairy farms in certain areas. The problem was that the dairy products went to the landlords, not to them. (A huge mistake had also been made in moving from making their polenta from wheat or chestnuts to using new world corn.)
Tenant farmers probably, as I said in my prior post, fared better. They certainly did in the parts of Italy that practiced the mesadro system, such as Tuscany and other scattered areas of the north. The land was leased for one third of the farm yield. As a result, mesadri who leased good land ate reasonably well, although there was no waste. As far as the milk from the milk cows is concerned, it was used to make butter and cheese, and the whey was given to pigs. And this is in a part of Italy where most people are lactose tolerant. The same situation would have applied to the American colonial farm with its one cow for the entire family.
Imho, I think that there's a lack of appreciation for the abject poverty in which most Europeans lived until very recent times, and a lack of information about the actual food habits of Europeans until very recent times as well.
