Why being a cleaner, McDonald’s worker or teaching assistant raises your risk of dementia

Spending a decade in a poorly-paid job could see you robbed of your memories in retirement, research suggests.

Scientists at New York’s Columbia University discovered people in low-paid careers suffer quicker cognitive decline, which is often a pre-cursor of dementia. 

Their study compared the earnings of almost 2,900 US adults during their 50s and 60s against how their brain aged over time.

People who were paid less two-thirds of the median wage suffered quicker memory loss than peers on a better salary. 

Such jobs would pay around $27,000 (£22,100) in the US, data suggests. 

The median salary in the UK is even less, meaning the threshold could sit as low as £17,000/year. 

Jobs that would fall into the bracket include entry-level cleaners, fast food workers and teaching assistants.

Average wages dropped at their quickest for more than two decades in April amid the cost of living crisis.

The study, published in the American Journal of Epidemiology, looked at the wages earned by nearly 3,000 people from 1992 to 2004.

All the participants, who were aged in their 50s when the project began, were split into three groups based on their earnings: those always earning low wages through the period, those who sometimes did and those who never did.

Researchers then used memory tests to examine how quickly their brain speed had declined between 2004 and 2016.

Results showed those on consistent low wages during the prime of their careers had significantly faster cognitive decline in later years.

Those on lower wages for a 12-year period from their 50s saw 10 per cent more memory decline in later life than those on better wages. 

For every decade, those on low wages had a brain equivalent to one year older than those who were above the salary threshold the entire time.

Lead scientist Dr Katrina Kezios said: ‘Sustained exposure to low wages during peak earning years is associated with accelerated memory decline later in life.’

The study did not outline the reasons why low wages are linked to cognitive decline.

Cognitive decline causes a fall in memory, language and problem-solving skills. Serious cognitive decline causes dementia.

But previous research has suggested it could be down to people earning low salaries living unhealthier lives.

This includes having a poor diet, smoking and drinking more. 

People with lower incomes also tend to have worse cardiovascular health and high diabetes rates, which are other risk factors for dementia. 

The researchers said further studies should be done to examine how increasing the minimum wage might lower cognitive decline levels. 

Senior author Dr Adina Zeki Al Hazzouri, an epidemiologist, said: ‘Our findings suggest that social policies that enhance the financial well-being of low-wage workers may be especially beneficial for cognitive health.

‘Future work should rigorously examine the number of dementia cases and excess years of cognitive aging that could be prevented under different hypothetical scenarios that would increase the minimum hourly wage.’