" Almost every major infectious epidemic, such as smallpox, polio, and the plague, happened after the Agricultural Revolution began. In addition, studies of recent hunter-gatherers show that although they don’t enjoy surpluses of food, they rarely suffer from famines or serious malnutrition. Modern lifestyles have also fostered new noncommunicable but widespread illnesses such as heart disease, certain cancers, osteoporosis, type 2 diabetes, and Alzheimer’s, as well as scores of other lesser ailments, such as cavities and chronic constipation. There is good reason to believe that modern environments contribute to a sizeable percentage of mental illnesses, such as anxiety and depressive disorders.2 The "

― Daniel E. Lieberman , The Story of the Human Body: Evolution, Health, and Disease