2023-10-25 22:25:00
For natural sciences and scientific medicine, human beings are biological organisms. Within our peculiarities as a species, three stand out: one, our long period of development and extrauterine growth until reaching maturity; two, the high rate of encephalization and three, we are organisms that generate culture as part of our adaptive strategies to the environment. These three things are closely related and each depends on the other.
The culture has its origin with the appearance of the Homo genus approximately 2.3 million years ago. Once generated, it developed with its own laws. He left it for another note to talk about the “nature” of culture. Suffice it to say for now that the environment in which humans evolve, unlike other animals, is mediated by culture, that is, our adaptation to the environment is bio-cultural. The scientific discipline that studies this is called biological anthropology.
The existence of the human being refers to a life cycle for which we must fulfill a series of vital functions common to all organisms, among which we highlight feeding and breathing.
In relation to human nutrition, it is characterized, unlike the vast majority of primates which are vegetarians, by being omnivorous. We incorporated meat as scavengers in the first instance and then from Homo ergaster and Homo erectus we became hunter-gatherers. Here it is important to note that when this happened in prehistory we reversed a selective pressure of millions of years. We go from possible prey to predators without modifying any important anatomical characteristic. That is to say, we did not get claws or super fangs or other things that make it easier for us to hunt. This ability was a cultural attribute – prehistoric lithic (stone) tools testify to this – but two things also helped us: a larger brain and the capacity for articulate language that greatly facilitates all tasks and the division of labor. Furthermore, at that evolutionary moment we exchanged a typical diet in many primates, known as “wandering”, in which each monkey or ape in the troop eats what it gets alone, for another one called commensality, which is obtaining, distributing and eat as a group or collectively, not as gregariousness, but as a solidarity group that strengthens its ties, norms and values, by sharing food.
The incorporation of meat and animal fat in the Homo genus was what allowed the development of a larger brain to be sustained. Let us keep in mind that of all the tissues, the nervous system is the one that consumes the most energy and fat is the food that contains the most energy per unit of weight. In primates, the human fetus is the one that accumulates the greatest amount of fat at the time of birth. Then breast milk is responsible for effectively nourishing the newborn. The attempt or pressure for commercial and industrial reasons by laboratories to replace breast milk is extremely dangerous and the main manufacturer of this type of food recently admitted (under pressure from the World Health Organization) that their campaigns were disastrous. Why is breast milk irreplaceable? In terms of nutrients (proteins, fats, carbohydrates), very good products can be manufactured. The problem is that there is no way to make antibodies, which is the protection that breast milk provides. Babies do not make antibodies until they are three months old and the only humoral defense they have are the immunoglobulins that the mother passes to them through milk. There are two forms of immunity: one is innate, mechanical and non-specific and the other is the acquired immune response that is highly specific, that is, it is the specific response to each infectious agent or antigens provided by B lymphocytes and antibodies. That cannot be manufactured by any laboratory or industry. Until women were employed outside the home, breastfeeding continued on average until they were two years old, which is the most recommended for the good future development of the baby.
On the other hand, it must also be taken into account that the human baby, unlike other primate babies, has the highest metabolic value per unit of weight. Gorillas, for example, which are strict vegetarians, have a higher basal metabolic rate in absolute terms, but if the metabolic rate is divided by unit of weight, human offspring surpass all of them. This accelerated metabolism of the baby, let’s only think about its heart rate and breathing – an adult with these values would be said to have tachycardia -, must be sustained with foods of high biological value and rich in energy: meat and animal fat they fulfill it.
Human nutritional needs vary at each stage of the ontogenetic cycle, but how they are met depends on each culture. What is available as food and its preferences are the result of bio-cultural evolution. Hindus do not eat beef, Mexicans and Chinese use a lot of spicy condiments, Koreans eat dogs and we saw with horror how in the 2001 crisis in some parts starving people ate cats. etc All of these are different cultural responses to the same biological need. Thus, each ethnic group has a type of diet that reflects its history and its relationship with the surrounding environment.
Currently we observe how, despite culinary traditions, the world is moving, as part of hegemonic and “globalist” cultural processes, towards greater consumption of industrialized, deseasonalized and low-quality foods that are imposed commercially. This has a negative health impact. The negative is not only in relation to bodily health, it is also negative in relation to our social ties. In all cultures and until not long ago, commensality reigned in every family, at every table. Today there is a certain food anarchy, similar to vagrancy. It is eaten alone, anywhere, at any time and anything. One day we eat a roast, the next day we eat leftovers, then a third day we diet or fast and another day we eat ethnic food because we are bored. It should also be noted that different movements such as veganism, probiotic naturism, fasting, etc. are resurfacing against the type of industrial diet. In short, the bioanthropological perspective has a lot to contribute about our diet.
*Dr. Juan Manuel Bajo / Full Professor by Competition of the subjects Biological and Cultural Anthropology and Fundamentals of Evolution of the Biology career of the Faculty of Exact, Physical and Natural Sciences of the National University of Córdoba.
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