Dementia is likely a ‘modern disease’ because there are so few mentions of severe memory loss in ancient Greek and Roman medical texts, scientists claim.

Experts scoured writings from 2,000 to 2,500 years ago – the times of Aristotle, Galen and Cicero.

Ancient Greeks recognised that ageing commonly brought memory issues, which would today be diagnosed as ‘mild cognitive impairment’.

But there was no evidence of anything approaching a major loss of memory, speech and reasoning as caused by Alzheimer’s and other types of dementia.

Professor Caleb Finch, from the University of Southern California, pored over a major body of ancient medical writing by Hippocrates and his followers.

Scientists believe dementia is probably a ‘modern disease’ because there are so few mentions of it in Greek and Roman medical texts (stock photo)

A picture of Hippocrates refusing presents from Artaxerxes I of Persia

A bust of Roman philosopher and statesman Marcus Tullius Cicero (106-43 BC)

The text catalogues ailments of the elderly such as deafness, dizziness and digestive disorders — but makes no mention of memory loss.

However, centuries later in ancient Rome, a few mentions do crop up.

Galen remarks that at the age of 80, some elderly begin to have difficulty learning new things.

Pliny the Elder notes that the senator and famous orator Valerius Messalla Corvinus forgot his own name.

And Cicero observed that ‘elderly silliness… is characteristic of irresponsible old men, but not of all old men’.

Professor Finch said the findings, published in the Journal of Alzheimer’s Disease, bolster the idea that Alzheimer’s is a product of modern living.

He added: ‘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, and 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.’

Romans and Greeks are widely thought to have had an average life expectancy of 30 to 35 years old, based on research which examined gravestones from the period.

However, dementia rarely strikes until sufferers are in their 60s and beyond – meaning the disease, which is thought to be caused by an abnormal build-up of proteins around brain cells and not an inevitable part of ageing, won’t have been as prevalent as it is now.

Some historians dismiss claims that Romans and Greeks had such a short lifespan, pointing to records that suggest people had to be in their 40s to hold certain political roles and that handful of people reached their 100th birthday.

Yet, while some may have become centenarians, it was much rarer than it is now.

Professor Finch speculates that as Roman cities grew denser, pollution increased, driving up cases of cognitive decline.

Scientists don’t know for certain that pollution causes dementia but studies have linked the two. Researchers believe it is down for tiny particles released by traffic fumes, which may be able to bass into the brain – possibly though the bloodstream or lining of the nose.

In addition, Roman aristocrats used lead cooking vessels, lead water pipes and even added lead acetate into their wine to sweeten it — unwittingly poisoning themselves with the powerful neurotoxin.

A few ancient writers recognised the toxicity of lead-containing material but little progress was made in dealing with the problem until well into the 20th century.

Some scholars even blame lead poisoning for the fall of the Roman Empire.

However, there’s no concrete proof that pollution or lead can directly cause memory loss.

The researchers drew on studies of today’s Tsimane Amerindians, an Indigenous people of the Bolivian Amazon, to support their findings.

The Tsimane — like the ancient Greeks and Romans — have a preindustrial lifestyle that is very physically active, and they have extremely low rates of dementia.

An international team of cognitive researchers led by Professor Margaret Gatz, also of USC, found among older Tsimane people, only about 1 per cent suffer from dementia.

In contrast, 11 per cent of people aged 65 and older living in the United States have dementia.

‘The Tsimane data, which is quite deep, is very valuable,’ Professor Finch said.

‘This is the best-documented large population of older people that have minimal dementia, all of which indicates that the environment is a huge determinant on dementia risk.

‘They give us a template for asking these questions.’