Written by Sajjad Hossain Adib, a student of University of Science and Technology, Chattogram (USTC)
A Mirror of Human Evolution
“how we eat and we are what”, the evolution of human dietary habits speculate the evolution of human themselves. In human history, key development like the appearance of stone tool technology, the switch to a meal based diet, control of fire, progress in cooking, fermentation techniques and the domestication of plants and animals have greatly affected human physic, physiological, social, cognitive and behavioral changes. Future technological breakthroughs might helps us to enable the early human encestors diets, which holds the potentials to tackle the modern health challenges.
Early Dietary Shifts
The history of human kind is also the history of human dietary habits. Hominins evaluation has compared major shifts. With deep functional recognition of the encephalic anatomy, hominins experienced an increase in body size and brain volume. Although the link among encephalization, body mass, dentition, tendencies, modification, interior anatomy and process is not fully understood but this principle poses a tradeoff between the brain and other organs, basically the digestive system and states. On the other hand, some experimental evidence has shown no negative endeavor between brain and digestive tract sizes. The relationship between brain size and fat storage, in the evolution of the mammalian brain could have alternative energy tideoffs. Again, the tendency of sharing high value foods between communities could have helped to develop advanced cognitional skills. Again, another mediating factor could be human microbiome which like to be shaped gut microbiota structure and functionality as well.
Plant-Based Diets: The First Staple
In the beginning, hominoids chased after frugivorous habits but after sometimes hominins diet fixed of plant-based foods such as fruits, leaves and some tough plant materials. To survive, hominins flourished strategies and abilities in order to make use of food which may have become important diet ingredients in times of food shortage. The adaptations to plant-based dietary habits show moderate-high inheritability, almost 49% as found in United Kingdom specimen in inquiring the genetics of choice of fruit and vegetable sources. Evolutionary adaptations to plant-based foods seem to have selected a set of genes, including one coding for salivary Alpha-amylase(AMY1) in taxonomic kingdoms can be found. However, the experimental results of AMY1 is warranting further research over it given that the role of AMY1 and its relationship with health results is still unclear.
Transition to Meat-Based Diets
The shift from plant-based diets to a diet organizing meat was simplified by technologies like stone tools. This stone tools early hominins used for their scavenging activities. Stone tools have numerous advantages including the ability to cut, scrape and process meat more perfectly. Corresponding to the heritability of the adaptations to red meat consumption is also rather high (39%-44%). Genetic adaptations to meat-eating would have happened as adaptive mechanisms which is also known as “meat-adaptive genes”(MAGs). Furthermore, meat consumption be able to increase microbiota-dependent cardiovascular disease risk. Again, red-meat is affluent in L-carnitine, resolved by the gut microbiome into trimethylamine which has been shown to favor atherosclerosis in murine models. Morever, in human taste meat-diets may have left genetic marks, which is influencing dietary choices and implementing human health in various ways. If we understand genetic variations properly we will be able to gain valuable insights into human evolution.
Fire and Dietary Transformation
The invention and control of fire brought about deep changes in the dietary habits of humans. It approves for the breakdown of complex carbohydrates and proteins, making them easier to digest, decreasing diet induced thermogenesis, increasing the bio availability of some nutrients and flourishing the energy gained from foods like meat and plants. Again, it also helps to eliminate detrimental pathogens.
Domestication and Stable Food Supply
In human history, the transition from a hunter-collector lifestyle to agriculture, dairying and animal husbandry offers a major dietary shift quicker by food processing production and storage technologies. Then, human began farming crops and domesticating animals, leading to a more stable food supply. This stable food supply ensured the growth of communities and placed the foundation for civilization.
Learning from Ancestral Diets
Scientific progressions have enabled the ingathering of novel direct paleodietary details. By researching how ancestral diets supported health and survival and understanding the evolution and the impact of “diet-related adaptive genes” can improve current dietary systems, addressing contemporaneous health challenges and reaching synthesis for human well-being and ecological footmark on the planet.
