Saudi Press

Saudi Arabia and the world
Monday, Jul 21, 2025

Social isolation linked to changes in brain structure and lower cognition ability

Social isolation linked to changes in brain structure and lower cognition ability

Why do we get a buzz from being in large groups at festivals, jubilees and other public events? According to the social brain hypothesis, it’s because the human brain specifically evolved to support social interactions. Studies have shown that belonging to a group can lead to improved wellbeing and increased satisfaction with life.

Unfortunately though, many people are lonely or socially isolated. And if the human brain really did evolve for social interaction, we should expect this to affect it significantly. Our recent study, published in Neurology, shows that social isolation is linked to changes in brain structure and cognition – the mental process of acquiring knowledge – it even carries an increased risk of dementia in older adults.

There’s already a lot of evidence in support of the social brain hypothesis. One study mapped the brain regions associated with social interaction in approximately 7,000 people. It showed that brain regions consistently involved in diverse social interactions are strongly linked to networks that support cognition, including the default mode network (which is active when we are not focusing on the outside world), the salience network (which helps us select what we pay attention to), the subcortical network (involved in memory, emotion and motivation) and the central executive network (which enables us to regulate our emotions).

We wanted to look more closely at how social isolation affects grey matter – brain regions in the outer layer of the brain, consisting of neurons. We, therefore, investigated data from nearly 500,000 people from the UK Biobank, with a mean age of 57. People were classified as socially isolated if they were living alone, had social contact less than monthly and participated in social activities less than weekly.

Our study also included neuroimaging (MRI) data from approximately 32,000 people. This showed that socially isolated people had poorer cognition, including in memory and reaction time, and lower volume of grey matter in many parts of the brain. These areas included the temporal region (which processes sounds and helps encode memory), the frontal lobe (which is involved in attention, planning and complex cognitive tasks) and the hippocampus – a key area involved in learning and memory, which is typically disrupted early in Alzheimer’s disease.

We also found a link between the lower grey matter volumes and specific genetic processes that are involved in Alzheimer’s disease.

There were follow-ups with participants 12 years later. This showed that those who were socially isolated, but not lonely, had a 26% increased risk of dementia.


Underlying processes


Social isolation needs to be examined in more detail in future studies to determine the exact mechanisms behind its profound effects on our brains. But it is clear that, if you are isolated, you may be suffering from chronic stress. This in turn has a major impact on your brain, and also on your physical health.

Another factor may be that if we don’t use certain brain areas, we lose some of their function. A study with taxi drivers showed that the more they memorised routes and addresses, the more the volume of the hippocampus increased. It is possible that if we don’t regularly engage in social discussion, for example, our use of language and other cognitive processes, such as attention and memory, will diminish.

This may affect our ability to do many complex cognitive tasks – memory and attention are crucial to complex cognitive thinking in general.


Tackling loneliness


We know that a strong set of thinking abilities throughout life, called “cognitive reserve”, can be built up through keeping your brain active. A good way to do this is by learning new things, such as another language or a musical instrument. Cognitive reserve has been shown to ameliorate the course and severity of ageing. For example, it can protect against a number of illnesses or mental health disorders, including forms of dementia, schizophrenia and depression, especially following traumatic brain injury.

There are also lifestyle elements that can improve your cognition and wellbeing, which include a healthy diet and exercise. For Alzheimer’s disease, there are a few pharmacological treatments, but the efficacy of these need to be improved and side effects need to be reduced. There is hope that in the future there will be better treatments for ageing and dementia. One avenue of inquiry in this regard is exogenous ketones – an alternative energy source to glucose – which can be ingested via nutritional supplements.

But as our study shows, tackling social isolation could also help, particularly in old age. Health authorities should do more to check on who is isolated and arrange social activities to help them.

When people are not in a position to interact in person, technology may provide a substitute. However, this may be more applicable to younger generations who are familiar with using technology to communicate. But with training, it may also be effective in reducing social isolation in older adults.

Social interaction is hugely important. One study found that the size of our social group is actually associated with the volume of the orbitofrontal cortex (involved in social cognition and emotion).

But how many friends do we need? Researchers often refer to “Dunbar’s number” to describe the size of social groups, finding that we are not able to maintain more than 150 relationships and only typically manage five close relationships. However, there are some reports which suggest a lack of empirical evidence surrounding Dunbar’s number and further research into the optimal size of social groups is required.

It is hard to argue with the fact that humans are social animals and gain enjoyment from connecting with others, whatever age we are. But, as we are increasingly uncovering, it also crucial for the health of our cognition.

Newsletter

Related Articles

Saudi Press
0:00
0:00
Close
Man Dies After Being Pulled Into MRI Machine Due to Metal Chain in New York Clinic
FIFA Pressured to Rethink World Cup Calendar Due to Climate Change
"Can You Hit Moscow?" Trump Asked Zelensky To Make Putin "Feel The Pain"
Nvidia Becomes World’s First Four‑Trillion‑Dollar Company Amid AI Boom
Iranian President Reportedly Injured During Israeli Strike on Secret Facility
Kurdistan Workers Party Takes Symbolic Step Towards Peace in Northern Iraq
BRICS Expands Membership with Indonesia and Ten New Partner Countries
Elon Musk Founds a Party Following a Poll on X: "You Wanted It – You Got It!"
AI Raises Alarms Over Long-Term Job Security
Saudi Arabia Maintains Ties with Iran Despite Israel Conflict
Russia Formally Recognizes Taliban Government in Afghanistan
Mediators Edge Closer to Israel-Hamas Ceasefire Agreement
Emirates Airline Expands Market Share with New $20 Million Campaign
House Oversight Committee Subpoenas Former Jill Biden Aide Amid Investigation into Alleged Concealment of President Biden's Cognitive Health
Amazon Reaches Major Automation Milestone with Over One Million Robots
Meta Announces Formation of Ambitious AI Unit, Meta Superintelligence Labs
China Unveils Miniature Insect-Like Surveillance Drone
Marc Marquez Claims Victory at Dutch Grand Prix Amidst Family Misfortune
Iran Executes Alleged Israeli Spies and Arrests Hundreds Amid Post-War Crackdown
Trump Asserts Readiness for Further Strikes on Iran Amid Nuclear Tensions
Iran's Parliament Votes to Suspend Cooperation with Nuclear Watchdog
Trump Announces Upcoming US-Iran Meeting Amid Controversial Airstrikes
Trump Moves to Reshape Middle East Following Israel-Iran Conflict
NATO Leaders Endorse Plan for Increased Defence Spending
U.S. Crude Oil Prices Drop Below $65 Amid Market Volatility
Explosions Rock Doha as Iranian Missiles Target Qatar
“You Have 12 Hours to Flee”: Israeli Threat Campaign Targets Surviving Iranian Officials
Oman Set to Introduce Personal Income Tax, First in Gulf
Germany and Italy Under Pressure to Repatriate $245bn of Gold from US Vaults
Iran Intensifies Crackdown on Alleged Mossad Operatives After Sabotage Claims
Trump Praises Iran’s ‘Very Weak’ Response After U.S. Strikes and Presses Israel to Pursue Peace
WATCH: Israeli forces show the aftermath of a massive airstrike at Iran's Isfahan nuclear site
We have new information and breaking details to share about what is shaping up to be a historic air campaign tonight
Six Massive Bombs Dropped on Fordow; Trump: 'A Historic Moment for the U.S., Israel, and the World'
Fordow: Deeply Buried Iranian Enrichment Site in U.S.–Israel Crosshairs
United States Conducts Precision Strikes on Iran’s Nuclear Sites
US strikes Iran nuclear sites, Trump says
Pakistan to nominate Trump for Nobel Peace Prize.
Israel Confirms Assassination of Quds Force Commander in Tehran
16 Billion Login Credentials Leaked in Unprecedented Cybersecurity Breach
Senate hearing on who was 'really running' Biden White House kicks off
G7 Leaders Fail to Reach Consensus on Key Global Issues
Mass exodus in Tehran as millions try to flee following Trump’s evacuation order
Iranian Military Officers Reportedly Seek Contact with Reza Pahlavi, Signal Intent to Defect
Vietnam Emerges as Luxury Yacht Destination for Ultra‑Rich
China's Iranian Oil Imports Face Disruption Amid Escalating Middle East Tensions
Trump Demands Iran's Unconditional Surrender Amid Escalating Conflict
Israeli Airstrike Targets Iranian State TV in Central Tehran
President Trump is leaving the G7 summit early and has ordered the National Security Council to the Situation Room
Netanyahu Signals Potential Regime Change in Iran
×