Scientists discover shocking new risk factor for dementia and it can begin decades before symptoms first appear

Scientists have made a breakthrough after discovering a new risk factor for dementia that can occur years before symptoms start to show.

More than seven million Americans are living with Alzheimer's, the most common form of dementia. One in three people in the US die with Alzheimer's or another form of dementia

It kills more than breast cancer and prostate cancer combined, according to the Alzheimer's Association.

Now, researchers have found the roots of cognitive decline could be found all the way back in childhood.

According the the major study, scientists found loneliness among children is strongly linked to accelerated cognitive decline, posing a higher risk of dementia in people age 50 and over.

Even those who had friends but experienced loneliness in their youth were deemed at higher risk of dementia - and even more interestingly, the link remained even in cases where people were no longer lonely as adults.

The decline starts in childhood (Getty)

The research suggests isolation in early years can influence the health of the brain much later in life.

The team of scientists from universities in Australia, the US and China, stressed the importance of studying this early stages of brain development since children are far more vulnerable to stress like loneliness, neglect, bullying and poverty.

Almost half of the 1,400 adults in the study said they were lonely and had few close friends as children, with the study defining 'childhood loneliness' as feeling lonely and lacking a close friend.

The study found people who said they were lonely as children entered their middle-aged years with lower memory and thinking skills.

The study, published in JAMA Network Open, also found their cognitive abilities plummeted at a faster pace each year compared to those who were not lonely as children.

The team tracked data from more than 13,592 people in China, examining their cognitive health from June 2011 to December 2018, to avoid any potential influence from the Covid pandemic, for seven years with repetitive cognitive tests to determine decline.

Social media isn't helping (Getty)

They found adults who said they had a lonely childhood and struggled to make any close friends were at a whopping 41 percent greater risk of dementia. People who answered 'yes' to 'I often felt lonely' had a 51 percent higher risk of dementia, even if they said they had a close friend.

The study is considered the first of its kind to identify childhood traumas like loneliness to later cognitive decline and dementia later in life.

The insight also comes as youth loneliness is on the rise in the US, partly as a consequence of social media.

According to Girl Scouts, a staggering 73 percent of girls between 11 and 13 years old reported feeling lonely last year.

A separate study by Common Sense Media reported that around 26 percent of boys between 11 to 17 year olds reported feeling lonely.