RT Journal
T1 INstinctive factors in customs of diet and food preparation
JF JAMA
JO JAMA
YR 2012
FD August 1
VO 308
IS 5
SP 438
OP 438
DO 10.1001/jama.2012.3120
UL http://dx.doi.org/10.1001/jama.2012.3120
AB 
It is a curious and almost inexplicable fact that there are certain dietetic customs, without any historic association but frequently with an underlying common physiologic significance, which have been practiced in common for years by untutored people at various places on the earth. This is true, for example, of the use of tea, coffee and the cacao products, which originated in the most diverse geographic regions, yet is undoubtedly based on an identical physiologic effect probably associated with the methylated purins, notably caffein, which they all contain. Thus instinctively in widely separated countries individuals unrelated by common racial bonds have sought precisely the same stimulants hidden, in the different cases, in plants of widely different botanic characteristics. A somewhat similar story might be told of the unconnected ways in which alcoholic beverages have found ready manufacture in diverse countries and a wide-spread use among peoples who have never experienced any intercommunication which might lead to the introduction of common habits of living.