Although representing 19% of the world population and being much more exposed than others to diseases, Africans are largely absent from clinical trials. This is the disconcerting finding from the study published on April 21 by the Journal of the American College of Cardiology, a medical journal specializing in cardiovascular disease research – writes Le Monde.
UNDERREPRESENTATION IN CLINICAL TRIALS
About thirty researchers analyzed randomized controlled clinical trials (RCTs) conducted in studies published between 2019 and 2024 in eight major international scientific journals such as the British Medical Journal, The Lancet, or Nature Medicine. Out of more than 2,000 publications, only 3.9% came from work conducted exclusively in Africa and 9.1% partially so. […]
DIFFERENCES IN DRUG RESPONSE
Several examples are known of risks associated with taking certain treatments that are increased in sub-Saharan patients. For example, some inhibitors used against arterial hypertension have been associated with a higher risk of Quincke’s edema in patients of African origin compared to white patients. There may also be differences in response or frequency of side effects for some type 2 diabetes treatments.
ETHICAL SCANDALS AND STRUCTURAL LIMITS
These cases also highlight another fact emphasized by the study: non-communicable diseases (such as hypertension or diabetes, among others), although increasing on the African continent, are the subject of fewer studies compared to infectious diseases. According to World Health Organization data, non-communicable diseases were responsible for 37% of deaths in Africa in 2019, compared to 24% in 2000.
Among the factors explaining the low percentage of clinical trials conducted in Africa are cited “limited internal investments, insufficiently developed infrastructure [and] a shortage of specialized personnel.” Even when analyzing in detail the African countries where registered trials were conducted, large disparities remain, as more than half were carried out in South Africa.
“Contrary to a certain portrayal of Africa, it is by no means a Eldorado for clinical trials,” explains Guillaume Lachenal, medical historian and professor at Sciences Po Paris. This image, stemming from real ethical scandals that have marked research on the continent – including recent ones –, hides according to him “the long-term legacy, which is mainly that of neglect.”
Furthermore, “there is a deep and legitimate mistrust that influences how African populations and governments interact with foreign researchers,” says Segun Fatumo, epidemiologist heading the genomic diversity chair at Queen Mary University (London) and the non-communicable diseases unit of the Medical Research Council in Uganda.
IS SOMETHING CHANGING?
The lack of diversity in research, particularly on non-communicable diseases, is also found in the field of genomics (the study of genomes, which concerns the entire set of genes, unlike genetics, which focuses on some of them).
In an article written together with Oyesola Ojewunmi in 2025, he cites several peculiarities that deserve to be studied more in depth. For example, some high-risk variants of the APOL1 gene, particularly frequent in people originating from West Africa, increase the risk of developing kidney diseases. They are also associated with kidney complications linked to sickle cell disease, a hereditary illness. Prevention efforts are also limited for non-European populations, as the assessment of genetic predispositions is based mainly on data from European populations.
Nevertheless, “things are changing,” assures Fatumo, who particularly cites the Human Heredity and Health in Africa initiative (H3 Africa): launched in 2012, it has enabled about fifty projects led by African scientists on the continent, both on non-communicable and infectious diseases.
(Excerpt from the foreign press review by eprcomunicazione)
