Alzheimer’s disease is the most common cause of dementia,¹ slowly robbing people of their memory, independence, and identity. At its core, Alzheimer’s involves the buildup of two proteins in the brain: amyloid-beta (amyloid-β), which forms sticky plaques between nerve cells, and tau, which forms tangles in the brain.² These changes trigger neuroinflammation, disrupt communication between neurons, and lead to brain cell death over time.³

While the exact cause of Alzheimer’s is still unknown and there is no confirmed way to prevent it, research suggests that addressing certain risk factors may help reduce the likelihood or delay the onset of the disease.⁴ This article explores 10 science-backed actions that may help reduce your risk. Whether you're looking after your own brain health or supporting someone else’s, these practical steps are a powerful place to start.

1. Know Your Family History, but Don’t Let it Define You

Your genes can influence your risk of Alzheimer’s, but they don’t determine your future. One of the genetic factors is the APOE gene, which comes in three main forms: ε2, ε3, and ε4. While ε3 is the most common, carrying the APOE ε4 variant increases your risk of developing late-onset Alzheimer’s.⁵

But genetics isn’t destiny. Many people with APOE ε4 never develop Alzheimer’s, and others without it do. 

If you have a family history of Alzheimer’s or know you carry APOE ε4, it’s especially important to apply the actions in this article. Knowing your risk is the first step in taking control of it.

2. Know Your Risk: 14 Factors You Can Do Something About

What if nearly half of all dementia cases could be prevented? According to a 2024 Lancet report, up to 45% of dementia cases may be avoidable by managing 14 modifiable risk factors throughout life.⁴ These aren’t obscure or out-of-reach changes; they’re everyday habits, health issues, and environmental exposures that can be addressed with the right support.

The 14 modifiable risk factors identified are:⁴

• High blood pressure (hypertension)
• Limited education
• Hearing loss
• Smoking
• Obesity
• Depression
• Physical inactivity
• Diabetes
• Social isolation
• Excessive alcohol consumption
• Head injury during mid-life
• Air pollution exposure later in life
• Untreated vision problems
• High LDL (low-density lipoprotein) cholesterol

If you identify with one or more of these risk factors, you may be at increased risk of developing dementia, but that also means there’s more you can do to reduce that risk. The actions in the rest of this article are designed to help. Even small changes may make a meaningful difference, especially when started early.

3. Don’t Let Infection Fuel Inflammation in Your Brain

You might not think a cold sore or gum infection has anything to do with Alzheimer’s, but growing evidence says otherwise. Certain bacteria and viruses can spark inflammation in the brain, even if the original infection occurs elsewhere in the body. And chronic inflammation is a known contributor to neurodegeneration.⁶

Here’s how it works: In response to infection, the brain may release amyloid-β to trap harmful microbes. But while this might help protect against infection, amyloid-β also builds up into plaques that damage neurons. Over time, this can lead to tau tangles, worsen inflammation, and drive a damaging cycle that kills brain cells and accelerates cognitive decline.⁶

Researchers have linked several pathogens to this inflammatory cascade, including:⁶

• Herpes simplex viruses (types 1 and 2)
• Varicella-zoster virus (chickenpox/shingles)
• SARS-CoV-2 (COVID-19)
• Certain gum and gut bacteria

The good news? There are simple, science-backed ways to lower your risk:

• Floss daily. Good oral hygiene helps reduce gum disease and the bacteria associated with brain inflammation.
• Stay up to date with vaccines. Immunisations protect against serious infections that may otherwise increase Alzheimer’s risk.

4. Don’t Let Stress Reshape Your Brain

Stress might just feel like part of life, but when it’s constant it can leave a lasting mark on your brain. Chronic psychological stress doesn’t just affect your mood; it triggers biological changes that are directly linked to Alzheimer’s disease.

Here’s what we know:

Long-term stress leads to persistent neuroinflammation, especially in areas like the hippocampus; the brain’s memory hub.⁷ This happens in part due to prolonged exposure to the stress hormone cortisol. Over time, this can damage neurons, impair memory, and even increase the production of amyloid-β and other toxic proteins associated with Alzheimer’s.⁸

Stress also contributes to other risk factors for dementia, including:⁸

• Depression
• Poor sleep
• Insulin resistance
• Systemic inflammation

The takeaway? Reducing stress is more than a mental health boost; it’s a long-term investment in brain health. Try these strategies:

• Practice mindfulness or meditation. Even a few minutes a day can help regulate stress responses.
• Get moving. Physical activity reduces cortisol and boosts mood-enhancing chemicals like serotonin and dopamine.

Talk it out. Social connection and psychological support help buffer the effects of stress.

5. Move Your Body, Grow Your Brain

Exercise doesn’t just build muscle; it can also help grow new brain cells. Once thought impossible, we now know that adults can generate new neurons, particularly in the hippocampus, a region vital for learning and memory. Physical activity is one of the most effective ways to support this process.⁹

At the heart of this brain-boosting effect is BDNF (brain-derived neurotrophic factor), a molecule your body produces during exercise. BDNF helps brain cells grow, survive, and form new connections. It’s essential for neuroplasticity, learning, memory, and mood regulation. Regular movement keeps BDNF levels up and supports long-term brain health.⁹

Animal studies have shown that:⁹

• Aerobic exercise sparks the birth of new neurons in the hippocampus (specifically in the subgranular zone of the dentate gyrus).
• BDNF binds to the TrkB receptor and triggers pathways that help strengthen connections between brain cells, which is important for learning and memory.
• Animals with higher BDNF levels perform better on memory tasks.

In humans, we can’t directly measure neurogenesis, but research links regular exercise to larger hippocampal volume, improved memory, and increased BDNF levels, especially with moderate-intensity workouts.⁹

That said, more isn’t always better. Overtraining can increase oxidative stress and dampen BDNF production. The sweet spot? Consistent, moderate exercise like brisk walking, swimming, or cycling.⁹

6. Prioritise Sleep: Your Brain Depends on It

Getting a good night’s sleep isn’t just about feeling refreshed; it’s essential for protecting your brain. Research shows that sleep problems precede the first cognitive symptoms of Alzheimer’s, and once the disease begins, it can make sleep even worse. It’s a vicious cycle, but one that may be breakable.

During deep sleep, your brain clears out waste products, including amyloid-β and tau, the same proteins that build up in Alzheimer’s. When sleep is disrupted or cut short, amyloid-β production increases, and clearance slows down, allowing plaques to form more easily. Amyloid-β disrupts the very brain regions that regulate sleep, making quality rest harder to achieve.¹⁰

Sleep deprivation also accelerates the spread of tau, another key protein linked to cognitive decline. Disrupted slow-wave sleep, the deep stage of non-REM sleep critical for memory, goes hand in hand with higher tau levels.¹⁰

In short, poor sleep may do more than leave you tired; it can speed up the biological changes that lead to Alzheimer’s. Aim for at least seven hours of sleep each night, and try to keep a regular sleep schedule.¹¹

7. Cut Back on Alcohol and Tobacco to Protect Your Brain’s Defences

Alcohol and tobacco both increase oxidative stress, a damaging process that becomes more harmful with age and plays a major role in Alzheimer’s disease.

Here’s what’s happening behind the scenes:

As your cells make energy, they naturally produce reactive oxygen species (ROS), unstable molecules that can damage cells if not properly cleared. The brain, with its high oxygen use and limited ability to regenerate neurons, is especially vulnerable to this kind of damage.¹²

Over time, excess ROS can:¹²

• Disrupt mitochondrial function, the powerhouses of brain cells
• Trigger DNA damage, including breaks that affect memory and cognitive function
• Promote the buildup of amyloid-β and tau, the hallmark proteins of Alzheimer’s

In Alzheimer’s disease, the brain shows more oxidative damage and weaker repair systems, making it harder to recover from daily wear and tear.¹²

Tobacco and heavy alcohol use accelerate all of this. They increase ROS, damage mitochondrial DNA, and reduce the brain’s ability to defend itself.¹³ Even moderate drinking has been linked to changes in brain volume and function.¹⁴

The good news? Limiting or quitting alcohol and tobacco can help reduce your risk of dementia by lowering oxidative stress and supporting overall brain health.

8. Feed Your Brain the Right Fuel

Diets high in sugar, salt, and ultra-processed foods are now recognised as major drivers of inflammation, a key contributor to Alzheimer’s disease. On the flip side, a nutrient-rich diet supports cognitive function, metabolic health, and a more resilient brain.¹⁵

Let’s break it down:

Sugar 

Excess sugar ramps up inflammatory markers such as IL-6 and TNF-α and contributes to insulin resistance and liver inflammation. Over time, high levels of fructose may damage the hippocampus, as well as worsen metabolic health and impair brain function.¹⁶

Salt

It’s not just your blood pressure that suffers. A high-sodium diet contributes to systemic inflammation by increasing oxidative stress and stimulating the release of pro-inflammatory cytokines such as IL-6, IL-1β, and TNF-α.¹⁷

Ultra-Processed Foods (UPFs)

These are the packaged snacks, sugary drinks, processed meats, and ready-to-eat meals that dominate modern diets. They're low in fibre and essential nutrients, and high in added sugars, trans fats, and artificial additives.¹⁸

• UPFs are associated with higher levels of inflammatory markers like C-Reactive protein and IL-6.
• Some additives may disrupt the gut microbiome and increase gut permeability.
• Chemicals from packaging (e.g., BPA) may act as hormone disruptors and promote inflammation.
  
  

The bottom line? A brain-healthy diet means cutting back on sugary, salty, and processed foods, and focusing on whole foods rich in fibre, healthy fats (including omega-3s), vitamins, and antioxidants.¹⁸

9. Stay Connected and Keep Learning

A rich social life doesn’t just feel good, it’s good for your brain. Staying socially and mentally engaged is one of the most consistent lifestyle factors linked to a lower risk of Alzheimer’s disease.¹⁹

Regular interaction with others, whether it’s catching up with friends, joining a walking group, or participating in community events, helps build what researchers call cognitive reserve. This is the brain’s ability to adapt and stay functional even in the face of age-related changes or early signs of Alzheimer’s pathology. In short, the more connected and mentally stimulated you are, the more resilient your brain becomes.^19,20

Loneliness and isolation, on the other hand, can trigger stress and inflammation, both of which increase dementia risk. Solitude isn’t always harmful, but if it leads to chronic loneliness, it may have lasting consequences for your cognitive health.¹⁹

To keep your brain active and connected:

• Spend time with friends and family regularly
• Join activity groups, volunteer, or attend community events
• Engage in mentally stimulating activities, such as reading, playing an instrument, or learning a new language
  
  

These kinds of challenges strengthen existing neural pathways and help form new ones, supporting memory, focus, and overall brain function.²¹

10. Protect Your Heart to Protect Your Brain

What’s good for your heart is also good for your brain. 

Here’s why it matters:

Your brain relies on a steady supply of oxygen and nutrients delivered through blood flow. When the heart and blood vessels aren’t working well, this supply is disrupted. Poor circulation can damage brain cells, reduce cognitive function, and contribute to the build-up of amyloid-β plaques and tau tangles, the signature features of Alzheimer’s.²²

Taking care of your heart means:

• Managing blood pressure, cholesterol, and blood sugar
• Avoiding smoking and limiting alcohol
• Staying physically active
• Eating a balanced, heart-healthy diet

Conclusion

While there’s no guaranteed way to prevent Alzheimer’s, the science is clear: your daily choices can make a meaningful difference. From managing stress and sleep to staying socially connected and protecting your heart, these actions support a healthier brain and may help reduce your risk over time.

If you’ve identified any risk factors in your own life, now’s the time to act. Small, consistent changes add up.

Want to go deeper? Explore the other three articles in our Alzheimer’s series to learn more about the science behind the disease, early warning signs to watch for, and how research is shaping the future of diagnosis and treatment.

References: 

1. World Health Organization. Dementia. Available at: https://www.who.int/news-room/fact-sheets/detail/dementia 
2. Sheppard O, Coleman M. Alzheimer’s Disease: Etiology, Neuropathology and Pathogenesis. In: Alzheimer’s Disease: Drug Discovery [Internet]. Brisbane (AU): Exon Publications; 2020 Dec 18. Chapter 1. Available from: https://www.ncbi.nlm.nih.gov/books/NBK566126/ 
3. Zhang Q, Yang G, Luo Y, et al. Neuroinflammation in Alzheimer’s disease: insights from peripheral immune cells. Immun Ageing. 2024;21(38).
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14. Daviet R, Aydogan G, Jagannathan K, et al. Associations between alcohol consumption and gray and white matter volumes in the UK Biobank. Nat Commun. 2022;13(1175).
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17. Dewan SMR, Meem SS, Proma AY, et al. Dietary Salt Can Be Crucial for Food-Induced Vascular Inflammation. Clin Pathol. 2024;17.
18. Tristan Asensi M, Napoletano A, Sofi F, et al. Low-Grade Inflammation and Ultra-Processed Foods Consumption: A Review. Nutrients. 2023;15(6):1546. 
19. Joshi P, Hendrie K, Jester DJ, et al. Social connections as determinants of cognitive health and as targets for social interventions in persons with or at risk of Alzheimer's disease and related disorders: a scoping review. Int Psychogeriatr. 2024;36(2):92-118. 
20. American Medical Association Ed Hub. Social Connection May Help Protect Against Alzheimer's. Available at: https://edhub.ama-assn.org/science-medicine-public-health/video-player/18903163 
21. Alzheimer’s Association. Stay Mentally and Socially Active. Available at: https://www.alz.org/help-support/brain_health/stay_mentally_and_socially_active 
22. Tini G, Scagliola R, Monacelli F, et al. Alzheimer's Disease and Cardiovascular Disease: A Particular Association. Cardiol Res Pract. 2020;2020:2617970. 

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