How social connections supports brain health | UniSC | University of the Sunshine Coast, Queensland, Australia

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How social connections supports brain health

Research links social connectedness with better mental wellbeing, reduced stress and a lower risk of dementia. Let's explore the science behind social connection and practical ways to strengthen it in everyday life.

What is social connectedness?

Social connectedness is more than simply not feeling lonely. It refers to having meaningful relationships, a sense of belonging, and people or communities you can rely on for support. These connections may come from family, friends, neighbours, community groups, workplaces, volunteering or shared interests.

It's important to understand the difference between three commonly confused terms:

Feeling connected to others and having a sense of belonging within your social networks.

A feeling that your social needs are not being met. Someone can feel lonely even when surrounded by people.

Having limited contact with other people. Some people may be socially isolated without feeling lonely, while others may feel lonely despite frequent social interactions.

Why social connections matters for your brain

Humans are biologically wired to connect with one another. Social interaction engages multiple brain regions involved in communication, empathy, emotional processing, memory, attention and decision-making. Researchers sometimes refer to this as the brain's social network.

We're wired for connection

Humans evolved in social groups, where survival depended on cooperation and connection. As humans evolved, so did the brain systems that support social behaviour. Unlike functions such as hearing or vision, social interaction relies on a widespread network of brain regions working together.

Connection helps the brain feel safe

The brain is constantly assessing whether situations are safe or potentially threatening. Research suggests familiar faces and social environments can help dampen the brain's defence mechanisms. Being able to recognise people in your neighbourhood, workplace or community may promote feelings of safety, belonging and wellbeing. Conversely, unfamiliar environments can be more likely to activate stress and vigilance responses.

Loneliness is a biological signal

Loneliness is more than an unpleasant emotion. From a neuroscience perspective, it can be viewed as feedback that an important human need is not being met. Much like hunger motivates us to seek food, loneliness may motivate us to seek social connection. The brain also responds differently when we feel lonely compared to when we feel connected. Loneliness can activate stress responses, whereas positive social interactions can increase the release of hormones such as oxytocin, which promote bonding and feelings of connection.

Social connection and dementia risk

One of the most compelling reasons to prioritise social connection is its relationship with cognitive health and dementia risk. Research suggests that up to 45 percent of dementia cases worldwide may be linked to modifiable lifestyle and health factors. Among these factors, social isolation is recognised as important, particularly for people over the age of 65.

Social contact is considered a protective factor against dementia because it helps build cognitive reserve. Cognitive reserve refers to the brain's ability to cope with age-related changes, injury or disease while maintaining function. People with higher cognitive reserve may be better equipped to compensate for changes occurring in the brain.

Other benefits of social connection

One of the most well-known studies exploring healthy ageing is the Harvard Study of Adult Development, which has followed participants since 1938. Its goal is to understand what contributes to a healthy, happy life.

At age 50, participants' satisfaction with their personal relationships was the strongest predictor of their health at age 80, more important than cholesterol levels and many other traditional health indicators.

The benefits don't stop there:

Social connection supports mental health

People who feel socially connected are less likely to experience depression and psychological distress. Social connectedness has also been associated with higher self-esteem, lower social anxiety and greater resilience during difficult life circumstances. This is particularly important because depression is itself a recognised risk factor for dementia. Supporting mental health may therefore also support long-term brain health.

Social connection helps regulate stress

Feeling connected to others can help regulate the brain's fight-or-flight response. Social relationships often provide emotional support, reassurance and a sense of safety, which can reduce the impact of stress on the brain and body.

Social connection supports physical health
Strong social relationships have been linked to improvements in cardiovascular health and immune function. Research has also shown that loneliness is associated with increased physiological stress and inflammation, which can affect overall health. Together, these mental and physical health benefits may contribute to healthier ageing and better brain health across the lifespan.

How much social connection do we need?

There is no single number of friendships, social interactions or community activities that is considered enough. People differ in how much social contact they prefer. Some thrive in large social networks, while others prefer a small number of close, meaningful relationships. Neither approach is right or wrong.

A helpful question to ask yourself is:

Do I feel connected, supported and fulfilled by my current relationships?

If the answer is no, feelings of loneliness may be a helpful signal that your social needs are not currently being met.

Social connections can be formed through common interest groups. Pictured are two ladies harvesting from a community garden.

Small steps matter

Social connection is an important part of healthy brain ageing, but everyone's circumstances are different. If you're feeling lonely or disconnected, be kind to yourself. Meaningful connections often develop gradually, and small steps taken today can help create opportunities for connection over time.

Download the social connection and brain health resource

Want other ways to boost your brain health?

Visit our Mind Your Future healthy brain ageing resources

Want to say thank you?

The best thank you is putting what you've learned into practice to support your wellbeing, and sharing this information with others. If you'd also like to support our research and help us continue creating free brain and mental health resources, we'd be grateful for your generosity.