Cognitive decline is often viewed as an unavoidable part of ageing.

However, large population studies increasingly suggest that everyday habits — particularly those influencing chronic low-grade inflammation — are closely linked to how the brain ages.

Inflammation does not usually cause symptoms early on. Instead, it builds gradually over years, shaped by diet, physical activity, sleep, stress, and metabolic health.

This article explores seven everyday habits that research has linked to slower cognitive decline or lower dementia risk, using cautious, evidence-based language throughout.

These habits cannot guarantee prevention. But together, they may meaningfully influence risk over time.

How inflammation fits into brain ageing

Chronic low-grade inflammation is increasingly recognised as a common biological pathway linking dementia with cardiovascular disease, type 2 diabetes, and frailty.

Inflammation can affect the brain by:

• Damaging blood vessels that supply oxygen and nutrients

• Disrupting insulin signalling in brain cells

• Promoting accumulation of pathological proteins

• Interfering with synaptic function and neuroplasticity

Many of the habits below are consistently associated with lower systemic inflammation, which may help explain their link to better cognitive outcomes.

1. Eating enough dietary fibre

What the evidence shows

In a large Japanese cohort followed for nearly 20 years, adults with the highest fibre intake had a 26% lower risk of dementia compared with those consuming the least.

Higher fibre intake is also associated with lower levels of C-reactive protein (CRP), a marker of systemic inflammation.

Why this may matter

Dietary fibre feeds gut bacteria that produce short-chain fatty acids, compounds known to regulate immune responses and dampen chronic inflammation.

Bottom line

Low fibre intake may contribute to inflammatory processes that affect the brain long before memory problems appear.

2. Being physically active — even if it’s not daily

What the evidence shows

Recent studies using UK Biobank and accelerometer data report that adults meeting physical activity recommendations had around 20–30% lower dementia risk, depending on activity pattern.

Importantly:

• “Weekend warrior” patterns (1–2 sessions per week) were still associated with lower risk than inactivity

• Benefits were seen with moderate-to-vigorous physical activity rather than light movement alone

Why this may matter

Physical activity reduces inflammatory markers, improves vascular health, and supports brain volume and connectivity.

Bottom line

Regular movement appears protective even when exercise is concentrated into fewer sessions.

3. Following a Mediterranean-style eating pattern

What the evidence shows

A UK Biobank study found that participants with the highest Mediterranean diet adherence had a ~23% lower risk of dementia compared with those with the lowest adherence.

Why this may matter

Mediterranean-style diets are consistently linked to lower inflammation, better lipid profiles, and improved insulin sensitivity — all relevant to brain ageing.

Bottom line

Greater adherence appears more important than perfection.

4. Sleep duration: a more nuanced picture

What the evidence actually shows

A 2024 meta-analysis found that short sleep (six hours or less) was linked to a higher risk of dementia only in studies with shorter follow-up periods (under 10 years). In studies that followed people for longer, this link was no longer seen.

The researchers suggest that in some cases, sleeping less may be an early sign of dementia already developing, rather than something that directly causes it.

What we can still say with confidence

• Consistently sleeping around 7–8 hours supports brain health

• Poor sleep increases inflammatory signalling and disrupts brain waste clearance

Bottom line

Short sleep may reflect early disease in some cases, but regular, adequate sleep remains important for overall brain health.

5. Listening to music regularly

What the evidence shows

In a large study of adults aged 70 and over, people who listened to music regularly had a lower risk of developing dementia than those who rarely or never listened.

Listening to or playing music was linked to the strongest benefit, particularly among people with higher levels of education.

This type of study can’t prove that music prevents dementia — only that the two are linked.

Why music is still interesting

Listening to music:

• Helps reduce stress

• Activates areas of the brain involved in memory and attention

• Supports mood and emotional wellbeing

All of these are linked to better brain resilience and lower inflammation.

Bottom line

People who regularly listen to music tend to have better brain health as they age.

While music may not directly prevent dementia, it is a simple, enjoyable habit that appears to support healthy cognitive ageing.

6. Keeping blood sugar within a healthy range

What the evidence shows

Meta-analyses consistently report that type 2 diabetes is associated with a 40–60% higher dementia risk.

Higher long-term blood sugar exposure (HbA1c) is also linked to faster cognitive decline, even below the threshold for diabetes.

Why this may matter

Poor glycaemic control promotes inflammation, oxidative stress, and vascular damage in the brain.

Bottom line

Metabolic health and cognitive health are closely connected.

7. Reducing ultra-processed foods

What the evidence shows

A UK Biobank study found that each 10-percentage-point increase in ultra-processed foods as a share of total daily calories (for example, from 20% to 30%) was associated with a 25% higher dementia risk.

Why this may matter

Ultra-processed foods are typically low in fibre and associated with higher inflammation and poorer metabolic health.

Bottom line

Even modest reductions may have meaningful long-term effects.

Putting It All Together

Age matters, but it’s never too late to benefit from healthier habits.

While many studies show that choices made in midlife influence dementia risk later on, others — including research on music listening — suggest that positive effects can still be seen in older age.

You don’t need to change everything at once: evidence suggests that benefits are additive, meaning small improvements can build over time.

Practical starting points include aiming for around 30g of fibre a day, 150 minutes of physical activity a week (even if concentrated into one or two days), keeping sleep regular at around 7–8 hours, replacing some ultra-processed foods with whole alternatives, and listening to music as part of daily routines.

It’s important to remember that most of this evidence is observational, meaning it shows associations rather than proof of cause and effect, and that individual circumstances — such as digestive conditions, shift work, or access to food — will vary.

Even so, the 2024 Lancet Commission estimates that around 45% of dementia cases worldwide may be preventable or delayed by addressing modifiable risk factors across life.

Taken together, the research suggests that everyday habits — particularly those that help reduce chronic inflammation — can meaningfully influence how the brain ages, even if they cannot remove risk entirely.