Beautiful Virgin Islands

Thursday, Jun 26, 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

Beautiful Virgin Islands
0:00
0:00
Close
Russian Shadow Payments via Cryptocurrency Reach $9 Billion
Explosions Rock Doha as Iranian Missiles Target Qatar
“You Have 12 Hours to Flee”: Israeli Threat Campaign Targets Surviving Iranian Officials
Macron and Merz: Europe must arm itself in an unstable world
Germany and Italy Under Pressure to Repatriate $245bn of Gold from US Vaults
Airlines Evaluate Flight Cancellations Amid Escalating US-Iran Tensions
Starmer Invites Innovators to Join Government Talent Scheme
UK Economy’s Strong Opening Quarter Shows Signs of Cooling
Harrods Seeks Court Order to Secure Al Fayed Estate for Victims
BA and Singapore Airlines Cancel Dubai Flights Amid Middle East Tensions
Trump Faces Backlash from MAGA Base Over Iran Strikes
Meta Bets $14 B on Alexandr Wang to Drive AI Ambitions
WATCH: Israeli forces show the aftermath of a massive airstrike at Iran's Isfahan nuclear site
FedEx Founder Fred Smith, ‘Heart and Soul’ of the Company, Dies at 80
Chinese Factories Shift Away from U.S. Amid Trump‑Era Tariffs
Pimco Seizes Opportunity in Japan’s Dislocated Bond Market
Labubu Doll Drives Pop Mart to Status as China’s Most Valuable Toy Maker
Global Coal Demand Defies Paris Accord Goals
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.
BBC Demands Perplexity AI Immediately Stop Using Its Content
Telegram Founder: I Will Leave My Fortune to Over 100 of My Children
Political Turmoil Resurfaces in Belgium Amid Economic Concerns
Fed policymakers divided on timing of interest rate cuts
Trump signals imminent agreement with Harvard University
Inheritance tax referendum alarms Swiss billionaire community
Japan cancels bilateral security meeting amid US defence demands
AI skeptic Emily Bender warns that ‘the emperor has no clothes’
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
Iranian Military Officers Reportedly Seek Contact with Reza Pahlavi, Signal Intent to Defect
FBI and Senate Investigate Allegations of Chinese Plot to Influence the 2020 Election in Biden’s Favor Using Fake U.S. Driver’s Licenses
Vietnam Emerges as Luxury Yacht Destination for Ultra‑Rich
Plans to Sell Dutch Embassy in Bangkok Face Local Opposition
China's Iranian Oil Imports Face Disruption Amid Escalating Middle East Tensions
Trump's $5 Million 'Trump Card' Visa Program Draws Nearly 70,000 Applicants
DGCA Finds No Major Safety Concerns in Air India's Boeing 787 Fleet
Airlines Reroute Flights Amid Expanding Middle East Conflict Zones
Elon Musk's xAI Seeks $9.3 Billion in Funding Amid AI Expansion
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
Taiwan Imposes Export Ban on Chips to Huawei and SMIC
Israel has just announced plans to strike Tehran again, and in response, Trump has urged people to evacuate
Netanyahu Signals Potential Regime Change in Iran
×