Hello
Today I'll try to write something without it being a reply even though it in fact is a reply. 
I looked up about beriberi. It is singales language and beri means weakness. When you say it twice, "beriberi" it means "big weakness". It affects muscles and neurology; you loose perception of touch and the heart works in a weak way which causes fluid to stay in your tissue. Not nice. The chines described the condition 2600 BC. 
I also looked up what food contains thiamine and found that practically all food has some thiamine except fats. The food richest in thiamine is pork - lentils and grain has less but more than any vegetable that I could find in my book. Very rich were soy beans. Since paleodiet means no seeds of any kind (do you agree?) it must mean that if we eat a variety of veges, meat and fish there would be no beriberi. Is'nt it likely that beriberi in Japan meant that those that got it only ate rice; that they were in fact very poor? As far as I know the condition was unknown of in Sweden in the old days even though people were very poor. Perhaps because we ate peas, cabbage, pork and fish and only rich people could eat sugar and white flour?!
Eva
PS When I wrote "only the slaughter and..." I meant it to be "only the butcher and God knows...". I meant no disregard. Sorry!