Dementia appears to be a modern condition that scientists now say is largely caused by laziness and pollution.

A study discovered Alzheimer’s disease appeared rarely in Greek and Roman medical texts – only really developing as polluted cities and inactive lifestyles grew.

According to The Sun, the ancient Greeks noted ageing brought on memory loss, but nothing like the loss of speech, reasoning and memory caused by dementia.

A few mentions did begin to crop up in ancient Rome centuries later.

One suggested that, at 80 years-old, some people would struggle to learn new things.

Authors now believe that the expansion of Roman cities brought more pollution and increased cognitive decline.

Roman aristocrats also used lead cooking tools, lead water pipes and used lead in their wine to sweeten it. This means they were unwittingly poisoning themselves.

The University of Southern California study found low rates of Alzheimer’s in a present-day indigenous tribe in Bolivia.

Professor Caleb Finch, from the University of Southern California, said: “The ancient Greeks had very, very few – but we found them – mentions of something that would be like mild cognitive impairment.

“When we got to the Romans, we uncovered at least four statements that suggest rare cases of advanced dementia – we can’t tell if it’s Alzheimer’s.

“So, there was a progression going from the ancient Greeks to the Romans.”

Professor Caleb Finch, from the University of Southern California, said: “The ancient Greeks had very, very few – but we found them – mentions of something that would be like mild cognitive impairment.

“When we got to the Romans, we uncovered at least four statements that suggest rare cases of advanced dementia – we can’t tell if it’s Alzheimer’s.