Nutrition And Physical Degeneration (book)
In 1939, Dr. Weston Price, a dentist, published Nutrition and Physical Degeneration, detailing his global travels studying the diets and nutrition of various cultures. The book concludes that aspects of a modern Western diet (particularly flour, sugar, and modern processed vegetable fats) cause nutritional deficiencies that are a cause of many dental issues and health problems.
In the book, Price claimed that various diseases endemic to Western cultures of the 1920s and 1930s – from dental caries to tuberculosis – were rarely present in non-Western cultures. He argued that as non-Western groups abandoned indigenous diets and adopted Western patterns of living, they showed increases in typical Western diseases. He concluded that Western methods of commercially preparing and storing foods stripped away vitamins and minerals necessary to prevent these diseases. (wikipedia)
So basically, this doctor, after traveling globally and studying the dental health of indigenous peoples, concluded that when these groups moved away from their natural diet - and ate more of a western (processed) diet - their health declined and diseases that were not present before were introduced.
"What he found was shocking. At the time, there were many cultures throughout the world that were far healthier than we are today. He documented 12 cultures in which every person had perfectly straight teeth and almost no cavities, for their entire lives. This despite an almost complete lack of dental hygiene. They also had very robust bodies, thick bones and a general resistance to disease.
The real punchline is his observation of what was happening to these cultures as they became Westernized. When they began eating refined flour, sugar, powdered milk and canned foods instead of their traditional fare, they developed rampant cavities, and their children had crooked teeth and thin bones just like we do in Western societies today." Stephan (GoodReads.com)