Diet and healthEdit
Compared to foragers, Neolithic farmers' diets were higher in
carbohydrates but lower in
fibre,
micronutrients, and
protein. This led to an increase in the frequency of
carious teeth
[7] and slower growth in childhood and increased
body fat, and studies have consistently found that populations around the world became shorter after the transition to agriculture. This trend may have been exacerbated by the greater seasonality of farming diets and with it the increased risk of
famine due to crop failure.
[6]
Throughout the development of sedentary societies, disease spread more rapidly than it had during the time in which hunter-gatherer societies existed. Inadequate sanitary practices and the domestication of animals may explain the rise in deaths and sickness following the Neolithic Revolution, as diseases jumped from the animal to the human population. Some examples of
infectious diseases spread from animals to humans are
influenza,
smallpox, and
measles.
[95] Ancient microbial genomics has shown that progenitors to human-adapted strains of
Salmonella enterica infected up to 5,500 year old agro-pastoralists throughout Western Eurasia, providing molecular evidence for the hypothesis that the Neolithization process facilitated the emergence of human-disease.
[96] In concordance with a process of
natural selection, the humans who first domesticated the big
mammals quickly built up immunities to the diseases as within each generation the individuals with better immunities had better chances of survival. In their approximately 10,000 years of shared proximity with animals, such as cows, Eurasians and Africans became more resistant to those diseases compared with the indigenous populations encountered outside
Eurasia and
Africa.
[97] For instance, the population of most
Caribbean and several
Pacific Islands have been completely wiped out by diseases. 90% or more of many populations of the Americas were
wiped out by European and African diseases before recorded contact with European explorers or colonists. Some cultures like the
Inca Empire did have a large domestic mammal, the
llama, but llama milk was not drunk, nor did llamas live in a closed space with humans, so the risk of contagion was limited. According to bioarchaeological research, the effects of agriculture on physical and dental health in Southeast Asian rice farming societies from 4000 to 1500 BP was not detrimental to the same extent as in other world regions.
[98]
Jonathan C. K. Wells and
Jay T. Stock have argued that the dietary changes and increased pathogen exposure associated with agriculture profoundly altered human biology and
life history, creating conditions where
natural selection favoured the allocation of resources towards
reproduction over
somatic effort.
[6]