There is no African Paradox
A paradox is an observation that does not fit into the world as we understand it. It is the departure from a paradigm, the accepted wisdom of the way in which the world works.
But a paradox is the stimulus for change. If the paradox is true then it means that the paradigm must change: our understanding of the way the world works must also change. This is the way that science progresses, in big leaps but not very often.
The example of combustion
The memorable example from the wonderful Age of Enlightenment concerns the understanding of combustion. The paradigm of the time was that the process of combustion involved the release of Phlogiston from the burning substance as heat and light. Phlogiston was regard as a natural component of all substances. This paradigm had worked well and everyone was happy, until Joseph Priestley in Yorkshire, UK, and independently Antoine Lavoisier in Paris, investigated combustion from the scientific viewpoint. Science means measurement, and they studied the weights of solids and the volumes of gases. They demonstrated that the products of combustion of a metallic element had a greater mass that the original. If combustion was the loss of phlogiston, how could mass increase? It was suggested that phlogiston might have negative weight, but stretched credibility too far even at that time.
They also noted that when combustion occurred and the weight of the solid increased, the volume of the enclosed air decreased. This was logically the result of consumption of a component of the air, what became known as oxygen (initially called "dephlogisticated air"). Priestley was reluctant to abandon the phlogiston hypothesis but Lavoisier was much more open-minded: the paradigm of combustion changed from phlogiston to oxygenation.
|Joseph Priestley 1733–1804
|Antoine Lavoisier 1743–1794
It was the careful and measurable observation of weight gain (and loss of volume of air) during combustion that was the paradox that changed the paradigm. This was a very big leap in understanding.
I emphasise "observation", because it is an important process that has been denigrated during the course of the Covid-19 pandemic in respect of the importance of vitamin D.
The "African Paradox"
I recently came across and read a paper entitled "Covid-19 pandemic: the African paradox", in what appeared at first sight to be a reputable journal, the Journal of Global Health.
This paper noted the very low levels of deaths from Covid-19 in Equatorial Africa compared to the temperate zone countries. It tried to explain this phenomenon in a number of unconvincing ways.
The obvious factor of geography was discussed, in relationship to temperature and humidity. However there was no consideration of sun exposure and vitamin D production. It was noted that the risk of Covid-19 death was less at higher altitudes, but no mention was made of greater sun intensity with altitude. I assume that the investigators were completely ignorant of the fundamental importance of the Sun and vitamin D in defensive immunity.
|Covid-19 deaths per million population in equatorial African countries,
and also UK, USA, and India for comparison.
The logic is this. A man of ethnic black African origin, perhaps from Uganda but living in the UK has a risk of death from Covid-19 even higher than ethnic white people, with the national average 1,870 per million population. But a man ethnically and presumably genetically the same, perhaps his brother, but living in Uganda would face a risk of Covid-19 death of only 7 per million. This is dramatic and requires an explanation. It is not skin colour that determines the so-called African paradox.
It has been stated in a UK Biobank study, see previous Blog post, that ethnic black African people living in the UK have a high death rate from Covid-19 because they are black. And so the very low level of deaths in Uganda and other equatorial African nations compared to the very high levels in the UK, cannot be explained on the basis of skin colour. On this basis they should have the same death rates.
Another recent paper has investigated the same pattern. It identifies that the incidence of Covid-19 is greater between latitudes 30 and 50 degrees north of the Equator that in the tropics. Air temperature and humidity are discussed but as usual there is no mention of the Sun and vitamin D.
Why are Covid-19 death rates so low in equatorial Africa? This is the alleged paradox: is the understanding wrong? Of course it is. There is a failure to understand some fundamental aspects of geography and human biology. The obvious difference is the country of residence with major differences in sunlight intensity.
The difference could be the result of much greater socio-economic deprivation in the UK and USA compared to all Equatorial African countries, but like the phlogiston theory, it stretches comprehension too far. The difference is most obviously the result of vitamin D deficiency in the UK as the result of geography and the position of the UK closer to the North Pole than to the Equator..
The tilt of the Earth on its axis determines that in the UK, the vitamin D production season is of only six months duration, but at the equator the season is the full twelve months. However in early August 2020 the Covid-19 deaths in the UK were in single figures, about the same as in equatorial African countries all the year round.
|The vitamin D production season in the UK
It is not just the comparison between deaths in equatorial Africa compared to temperate zone countries that require explanation, but also why there has been such a dramatic seasonal variation in the temperate countries only. Surely something to do with the sun.
It does not take a high level of education to observe the difference between a December day in the UK at 53 degrees north of the equator, and the same day in Uganda which is on the equator. The difference is the light and heat, the results of intensity of the Sun determined by the elevation of the Sun above the horizon.
Studies of the Maasai tribesmen in East Africa have shown them to have an average blood vitamin D level of about 40ng/ml, 100nmol/L. This can be regarded as the ideal as determined by natural evolution. Experience during the Covid-19 pandemic has confirmed that this is ideal, with critical illness and death being extremely rare at and above this blood level.
Migration and Latitude
When living in tropical or semi-tropical countries there is an evolutionary advantage of a protective melanin-rich skin. UV from the sun can be very damaging and protection by nature's sunscreen is essential. Although melanin blocks most UV penetration into the skin, adequate blood levels of vitamin D will be produced unless there is extensive covering with clothes. Most of the time spent indoors during the hours of daylight is characteristic of a significant part of the populations, mainly as a result of a move from an agricultural to an office working environment. This can also lead to vitamin D deficiency, There is also the influence of modesty of dress, amplified by religious rules.
Migration of humankind from Africa into northern Europe created an environment in which the summer is short and the sun is relatively low in the sky, with reduced intensity. For people with melanin-rich skin, vitamin D deficiency became very likely with health consequences. Evolution in Europe during thousands of years selected a white skin to have a biological and survival advantage because of better production of vitamin D.
The sub-optimal immunity caused by vitamin D deficiency is a survival disadvantage, but mainly in the older population, and this would not have an influence on the extinction of dark-skinned humans who might have migrated to Northern Europe. However during recent years childhood rickets due to severe vitamin D deficiency (previously a characteristic of the industrial revolution) has been seen in children of parents who had moved to the UK from tropical Africa and the West Indies, and also from South Asia. Rickets is characterised by soft bones, and a result is compression of the pelvic outlet. This can have a devastating effect on young adult females as it will result in obstructed labour, with death of both mother and child in the absence of the advanced maternity care (especially Caesarian section) that we have today. The end of successful reproduction would indeed lead to extinction of those with a high incidence of serious vitamin D deficiency in childhood.
Migration in the 20th and 21st centuries
The rapid transmigration of many people from tropical Africa, the West Indies, and South Asia during the years since 1950 has brought to attention the health disadvantage of a melanin-rich skin when living closer to the North Pole than to the Equator.
This has been well-established during these years, but I am both amazed and saddened that the knowledge of it is not wide-spread, even among doctors and other health workers. A higher than average death rate from Covid-19 was completely predictable at the onset of the pandemic and was obvious during its first few weeks. But the importance of vitamin D deficiency in their deaths has been consistently denied.
The UK Standing Advisory Group on Emergencies (SAGE) is supposed to be composed of the best brains in the nation, but that might not be the case. A comment by SAGE appeared in the national press.
It is beyond belief that SAGE could have come to such a conclusion. I have mentioned in previous posts that 24 out of 25 (96%) of working doctors in the UK who died from Covid-19 between March 23rd and May 2nd 2020 were of Black African or South Asian ethnicity. How has this escaped the attention of national bodies composed of allegedly clever people? If there is a paradox, this is it. To regard vitamin D deficiency as just a "rumour" for excess deaths from Covid-19 among BAME people is an insult, in particular to the 24 ethnic Black African and South Asian doctors who died while working during the pandemic (an additional one was ethnic white). The attitude of SAGE is a disgrace, and I hope that an apology will be forthcoming.
Three UK national committees reported on the high Covid-19 death rate among the ethnic Black African and South Asian groups but failed to mention the deaths of doctors or to consider vitamin D. This failure has led to the deaths of many people. I hope for even more apologies in the near future.
These reports did not mention the African non-paradox. When trying to reach an important conclusion, it is essential to to use all possible evidence, but this sound advice was not followed. This process is clear from a court of law where evidence must not be with-held, and it should be the same in health issues. However a report, or even alleged "proof", is never a final judgment. As the great economist John Maynard Keynes stated: "When the evidence changes, I change my mind. What do you do, Sir?"
The past year has seen an enormous amount of evidence to support the correction of vitamin D deficiency in our defence against Covid-19, but government advisors have shown no sign of absorbing this evidence. If only they would listen to the wisdom of Keynes.
The African experience is not a paradox. It shows the importance of the Sun and vitamin D, and it amplifies the serious disadvantage of ethnic African people living in the UK without taking vitamin D to correct an inevitable deficiency.
Ethnic minorities from Africa, the West Indies, and South Asia living in the UK and other temperate zone countries have been failed very seriously by public health authorities by their ignoring of critically important evidence. These ethnic minorities should all be taking vitamin D, and the ideal time to check for deficiency is during pregnancy.
No child should be born vitamin D deficient.
No-one should die from Covid-19 when vitamin D deficient.