Brain health is often linked to age and genetics, but research shows that the picture is more flexible. A large 2025 study published in the Journal of Neurology, Neurosurgery & Psychiatry identified several modifiable risk factors shared by stroke, dementia, and late-life depression — suggesting that some aspects of brain health may be influenced long before symptoms appear.

In this article, we look at modifiable risk factors of stroke, modifiable risk factors for dementia, and modifiable risk factors depression — and why many of them overlap.

Read along to learn what the study found, why these conditions share more risk factors than we might think, and what it may mean for a more preventive approach to healthy aging.

Different conditions, shared risks

Stroke, dementia, and late-life depression are fundamentally different conditions. They vary in symptoms, progression, and impact on daily life. They are also highly individual in how they develop, meaning that two people with the same diagnosis may experience very different disease courses.

According to the World Health Organization, stroke, dementia, and depression affect the brain and daily life in different ways:

• A stroke happens when blood flow to the brain is interrupted and often appears suddenly, with symptoms such as paralysis, speech difficulties, or confusion.
• Dementia develops more gradually and refers to a group of conditions that affect memory, thinking, and daily functioning.
• Depression affects mood, energy, and the ability to function in everyday life, and in older adults it can sometimes be harder to recognise because symptoms may overlap with other health changes.

Although their symptoms and disease courses are very different, the study brings these conditions together for a clear reason: they share several modifiable risk factors and some underlying biological mechanisms, particularly those linked to vascular health and overall brain function.

About the study and DALY

Researchers reviewed studies published between 2000 and 2023 and identified 182 relevant meta-analyses. Of these, 59 were included in the final analysis.

What makes this study interesting is that the researchers did not simply list separate risk factors. They compared them across stroke, dementia, and late-life depression to see which factors had the greatest combined impact on brain health later in life.

To do this, they used a measure called DALYs, short for “disability-adjusted life years.” DALYs estimate the overall burden of a disease by combining:

• years of life lost due to early death
• years lived with disease, disability, or reduced health

This matters because one risk factor may have a strong effect on stroke, but a smaller effect on dementia or late-life depression. By using DALY-weighted calculations, the researchers could estimate which modifiable risk factors had the greatest overall impact across all three conditions.

Modifiable risk factors of stroke, dementia, and depression

Before looking at the findings, it helps to clarify what modifiable risk factors are.

A modifiable risk factor is a health factor, behaviour, or exposure that can be influenced over time. This includes factors such as blood pressure, smoking, physical activity, sleep, diet, blood sugar, and stress.

They are different from non-modifiable risk factors, such as age, genetics, and family history, which cannot be changed.

In this study, the researchers identified 17 modifiable risk factors across stroke, dementia, and late-life depression. One of the key points is that these factors rarely act alone. They often overlap and influence each other:

Poor sleep can affect stress. Stress can affect blood pressure. Blood pressure can affect vascular health. Over time, these patterns may influence long-term brain health.

So, can modifiable risk factors be changed or eliminated? In many cases, they can be improved or managed, but not always completely eliminated. That distinction matters. Prevention is not about perfect control, but about influencing the factors that can be changed over time.

Main findings from the study

One of the most important insights from the study is that not all risk factors carried the same weight in the DALY-weighted combined outcome.

The study identified 17 modifiable risk factors that overlap across stroke, dementia, and late-life depression, showing that these conditions are not driven by completely separate causes, but by a shared set of underlying factors.

A key finding is that vascular and metabolic factors play a dominant role. High blood pressure had the strongest overall impact in the model, followed by factors such as elevated blood sugar, reduced kidney function, and smoking.

This highlights a clear pattern: many of the most influential risk factors are linked to cardiovascular and metabolic health, rather than being specific to a single disease.

Other important factors identified in the study include sleep disturbances, stress, and social isolation. These factors may appear less direct, but still showed measurable associations with the combined risk of the three conditions.

At the same time, the study identified several factors associated with lower risk. Physical activity, cognitive activity, social engagement, and a sense of purpose in life were all linked to reduced risk in the combined model.

Related: Blood pressure and longevity: Why it matters as we age

What this means for brain health

The study points to a clear idea: brain health is closely connected to the health of the whole body. Blood pressure, blood sugar, sleep, stress, movement, and social connection do not work in isolation. They influence each other over time.

This is what makes the findings useful. A long list of modifiable risk factors can feel overwhelming, but the study helps show that many of them are connected. Supporting one area can often support another. Better sleep, for example, may help with stress regulation, which can also support blood pressure and metabolic balance over time.

For brain health, this means prevention does not have to start with everything at once. It can start with a few steady habits: moving regularly, protecting sleep, staying mentally active, keeping social connections strong, and paying attention to blood pressure and metabolic health.

You might also like: Study: Social connection and mortality risk in older adults

Prevention and a more holistic approach

The findings point to a more holistic approach to health. Brain health is not shaped by one factor alone, but by how different areas of health interact over time. Blood pressure, metabolic balance, sleep, movement, stress, and social connection are all part of the same system.

Read all our lifestyle blogs to improve longevity here: Longevity blogs

In practice, this means building a stable foundation. A balanced diet, regular movement, sufficient sleep, stress management, mental stimulation, and strong social connections all play a role. These habits do not need to be perfect, but consistency over time is what supports long-term health, energy, and function.

Beyond the study itself, this also fits with a broader approach to healthy ageing. Supplements can have a place within that approach—not as a replacement for lifestyle, but as support for specific needs within a consistent routine. At Purovitalis, this is how supplementation is approached: as one element within a science-based lifestyle that supports how you feel, think, and function over time.

Find all longevity supplements here: Longevity supplements

Stroke, dementia, and late-life depression are different conditions, but they share several modifiable risk factors that shape risk over time. This study does not offer a single solution. It offers something equally valuable: a clearer sense of where attention may have the greatest impact.

Not everything can be controlled, but some factors can be influenced. Over time, that influence adds up.