Health Science Reviews

by Sivanesan N. Dharmalingam 

There was a time when all humans lived as hunter-gatherers. Not that I’m about to detail the complex evolution of Homo sapiens, but let’s just say that we all have origins that trace back to a time long before city life. In this time our ancestors would trek across the African plains to hunt animals for meat, which they would bring back to camp and feed their families, along with vegetables, fruit and nuts foraged from around the camp. Now when we hunt, it’s for the best deals on the best brands and foraging is confined to the (sometimes) not-so-fresh produce from local supermarkets, all conveniently accessible at the shopping-mall closest to us.

Figure 1: Nomadic men leaving camp to hunt an animal, staple in their diet of the !Kung for ~11 000 years – the nocturnal springhare (2).

One of the few hunter-gatherer societies that still exist today are the !Kung, of south-west Africa.
Yes, that is where the exclamation mark is supposed to go – it indicates that there is an alveolar-palatal-click at the beginning of the word. Place the tip of your tongue on the roof of your mouth, behind your teeth and sharply draw it backwards… !Kung..!Kung. Awesome, lets continue:
For over 11 000 years most of the !Kung had hunter-gatherer lifestyles, hunting some of the same animals since the Pleistocene, until about 50 years ago. Now, less than 5% of ~30 000 !Kung people still practice this lifestyle in the 21^stcentury. Most population groups have adopted an agrarian (practice cultivation of land for farming) lifestyle, having settled down near Bantu (pastoralists – cattle herders) villages. This rapid social change is accompanied by social, dietary and demographic changes. These changes are interesting, anthropologically, since they might possibly reflect some of the changes that occurred during the Neolithic revolution, which saw a wide-scale pattern of previously nomadic peoples establishing permanent settlements (transitioning from hunter-gatherers to agrarian lifestyles) and the development of social class and civilisation(~12 000 years ago).

Some of the most interesting differences between nomadic bands and the settled peoples are related to the changes in behavior, status and the role of !Kung women. In nomadic bands, men leave camp to hunt for meat, whilst women – responsible for foraging – are as mobile as the men and contribute ~50% of the food for the band from foraging. Their diet is widely acclaimed as being nutritional and well-balanced and is reported that very few nutritional and even old-age related deficiencies and disease (associated with complex societies) existed in these peoples. Both sexes equally contribute to sustenance of the group and as such, these women  are autonomous and they have higher egalitarian status, which give them the ability to directly influence group decisions. Some men and women stay behind everyday to care for children and maintain the camp.
YES!!! Finally, a society which treated both sexes equally!
However, with the transition to sedentary lifestyles, the !Kung women are losing their egalitarian status. The men of the sedentary !Kung leave their villages to work –  farming and herding cattle on Bantu farms. Women remain, preparing food (a shift to include cow’s milk and grain) and caring for the village and the children; not mobile, contributing less to the food supply and therefore are more reliant on the men. !Kung men learn the language(s) and practices of the Bantu when working on the farms. They echo the ideals of the male-dominated Bantu society into their own and the Bantu-people only deal with the !Kung men, creating increasingly subservient roles for the women.

Children are raised differently in settled !Kung villages. In nomadic bands, there aren’t groups based on age and sex. The children play together in a non-competitive environment, where distinct gender roles and aggression are discouraged and actively avoided.  In the settled villages there is an increase in population size (more children) and groups of same sex and similar ages for playing, which breeds competition. I must admit that last sentence quite accurately depicted my high-school experience. The boys are on their own, expected to herd cattle and learn farming.

Figure 2: group of nomadic !Kung children, depicting mixed ages (3).

The girls have no comparable experience and help women, in the village, with chores. The increase in population sizes are attributed to the increase in body size of the settled !Kung, which is due to the increase in food supply. The nomadic bands have a natural birth control – the menarche (first menstrual cycle) of girls occur later (~16 years old) and women have babies less frequently, with a woman’s first birth around 19-20 years old and an average birthing interval of 4 years. This is related to food supply – body fat percentage must exceed a minimum for onset, and maintenance after, menarche. Due to the lack of soft food, children are nursed for ~4 years and in those years the lactating woman may have too little body fat for ovulation to occur and she rarely falls pregnant in this time. Settled groups have 30% shorter birthing intervals and have more children, owing to the introduction of cow’s milk and grain meal into the infants’ diet.

There is no confirmation that the !Kung peoples transition from hunter-gatherers into agrarian societies are an accurate representation of the events of the Neolithic revolution. However, I personally find the social egalitarianism and equality of gender roles portrayed by the nomadic bands of the !Kung fascinating! The idea that a simple lifestyle revolving around basic needs had, and – in the few societies that remain – have equality of sexes brings to attention that social classes, and a gender biased society are not “a thing of the past”, but rather completely out of place in the progression of our species. In our society today, where women and men have equal potential, the opportunity to contribute to our advancement should be afforded to all.

References

1. Kolata, G.B., 1974. ! Kung hunter-gatherers: feminism, diet, and birth control. Science, 185(4155), pp.932-934.
2. Lee, R.B., Lee, R.B. and DeVore, I. eds., 1976. Kalahari hunter-gatherers: Studies of the! Kung San and their neighbors. Harvard University Press.
3. Hawkes, K., O’Connell, J. and Blurton Jones, N., 2018. Hunter‐gatherer studies and human evolution: A very selective review. American journal of physical anthropology, 165(4), pp.777-800.

By Kutlwisiso Setlogelo

Covid-19 is a severe disease that has claimed the lives of millions across the world without the development of effective treatment to stop it.  It has been reported that comorbidities increase the likelihood of developing serious and fatal outcomes. Particularly, cardiovascular disease (CVD) which is a group of heart and blood vessel disease including diabetes and high blood pressure, have featured most commonly in Covid-19 patients who have been in critical care or have demised. It is thus suggested that there is a link between a history of CVD and the outcome of Covid-19. However, this is deeply concerning because CVD in itself is the leading cause of death and disability globally. Therefore, urgent investigations need to be done to understand how SARS-Cov-2 further threatens the health of those with CVD.

A study by Nishiga et. al looked into several investigations that has been done up to this point. Research shows that Sars-Cov-2 exacerbates heart disease by causing further heart damage, giving rise to a heart attack. In fact, the rate of death due to Covid related-heart attacks is doubled in patients with a history of heart disease. So, what exactly is the mechanism? ACE2 is a receptor found on heart cells that allows for the invasion of Sars-CoV-2. With this said, samples were taken from the heart to assess if the heart damage was because of direct invasion of the virus. Only some studies found the virus in the heart cells as well as some immune cells which was suggestive of direct attack. Other studies suggest that the progression of heart attacks may be due to the reduction of ACE2 that happens after the cells are infected. The loss of ACE2 has been attributed with the narrowing of blood vessels, which compromises the supply of nutrients to the heart, leading to heart attack. The narrowing of the blood vessels is accelerated in the patients with uncontrolled diabetes and high blood pressure which explains why the rate of death is highest among these patients infected with SARS-Cov-2. Furthermore, other studies show that the immune response against Sars-Cov-2 may also contribute to affecting the flow of blood to the heart. With this said, if you are known to have a history of heart problems or have diabetes and high blood pressure, it is preferable that you stay at home. Given the fact that health resources are limited and a cure is unavailable, the only safe thing to do for oneself is to diligently follow regulations and restrictions because your life may depend on it.

References

Wu, J. C. (2020) ‘COVID-19 and cardiovascular disease: from basic mechanisms to clinical perspectives’, Nature Reviews Cardiology. Springer US. doi: 10.1038/s41569-020-0413-9.

Fitzmaurice, C. et al. (2019) ‘Global, regional, and national cancer incidence, mortality, years of life lost, years lived with disability, and disability-Adjusted life-years for 29 cancer groups, 1990 to 2017: A systematic analysis for the global burden of disease study’, JAMA Oncology, 5(12), pp. 1749–1768. doi: 10.1001/jamaoncol.2019.2996.