Why dementia rates are rising fastest in Africa

By 2050, the number of people living with dementia worldwide is projected to triple, from roughly 55 million today to over 150 million. The growth is not evenly distributed. The fastest increase is happening in sub-Saharan Africa, where dementia prevalence is expected to grow by a factor of more than three over the next 25 years.

This is not because Africans are uniquely vulnerable. It is because most of the conditions that prevent dementia globally are conditions that have not been built yet across the continent.

What is driving it

Several converging factors:

A rapidly ageing population. The age structure of African countries is changing faster than almost anywhere else. Life expectancy has risen sharply over the past two decades. The continent is now home to the fastest-growing population of people over 60 in the world. Dementia is overwhelmingly an age-related condition, so more older adults means more cases.

Rising rates of cardiovascular risk factors. Hypertension, type 2 diabetes, and high cholesterol are all rising rapidly as urbanisation and dietary change accelerate. All three are independent risk factors for dementia.

Limited diagnosis and care infrastructure. Most African countries have very few neurologists. The continent has roughly one neurologist per million people. Dementia cases that would be diagnosed and managed elsewhere often go unrecognised, untreated, and under-counted.

Cognitive screening tools that do not fit. Standard global instruments like the MMSE and MoCA were validated in highly literate Western populations. Applied without adaptation, they tend to misclassify cognitive status in populations with different educational and cultural backgrounds.

What the response looks like

The interventions that lower dementia risk are mostly the same everywhere. What changes is how to deliver them at scale in resource-constrained settings:

• Hypertension treatment is the single most impactful intervention. Blood pressure control across a population would lower dementia incidence substantially.
• Education access beyond primary school is one of the strongest protective factors against cognitive decline.
• Hearing care matters for the same reasons we will write about in our next post on hearing aids and dementia risk.
• Cognitive screening adapted for the population rather than imported wholesale. This is part of what we mean by locally appropriate cognitive screening.

Why we work here

Neureka is based in Accra and Paris partly for this reason. The brain health needs of African populations are large, growing, and underserved. Most of the world's neuroimaging research is done on a fraction of the world's brains. Most cognitive screening is validated in populations very unlike ours.

The infrastructure to do this work the right way needs to exist on the continent, not just be visited from elsewhere. That is the slower, harder, and more important version of brain health work.