I recently tuned into an episode of The Doctor’s Kitchen podcast featuring Dr. Louisa Nicola, who spoke about how specific nutrients and forms of exercise can protect brain health, which prompted me to dive deeper into the science of preventing Alzheimer’s disease and write an in-depth article about it. Here, I will explore the role of nutrition, supplements, exercise, sleep, and other lifestyle habits that can strengthen and protect the brain. This guide will outline the most evidence-based strategies for reducing Alzheimer’s risk. For me, what began as inspiration from a podcast turned into a deeper appreciation of how everyday habits shape long-term brain health.
Understanding Alzheimer’s Disease: Non-Modifiable and Modifiable Risk Factors
Alzheimer’s disease, the most common type of dementia, is characterised by symptoms such as impaired memory, challenges with communication, and problems carrying out everyday activities. In the UK alone, 982,000 people are estimated to live with dementia, with 1 out of 4 people aged over 65 suffering from the condition. With no cure currently available, prevention has become a critical area of focus for researchers and healthcare professionals. While there is no guaranteed way to avoid Alzheimer’s, researchers have identified both non-modifiable and modifiable risk factors that influence the likelihood of developing the disease:
Non-modifiable risk factors include:
- Age: The biggest risk factor. the likelihood of developing Alzheimer’s increases significantly as we age.
- Genetics: Certain gene variants, such as APOE4, increase susceptibility, though not everyone with these genes develops Alzheimer’s.
- Sex: Women are at higher risk than men, possibly due to hormonal or biological differences. Nearly two-thirds of people living with dementia in the UK and the US are women
Modifiable risk factors include:
- Cardiovascular health: High blood pressure, diabetes, obesity, and high cholesterol all raise risk.
- Diet and physical activity: Poor diet and lack of exercise contribute to brain ageing, while healthier habits protect against decline.
- Sleep quality: Chronic sleep problems reduce the brain’s ability to clear toxic proteins associated with dementia.
- Hearing loss: Now recognised as a risk factor, untreated hearing loss strains the brain and increases social isolation.
- Social engagement: Social isolation is linked to higher dementia rates.
- Smoking: Smoking can lead to inflammation and vascular problems.
- Excessive alcohol consumption: Heavy drinkers are more likely to develop dementia.
- Air Pollution: People exposed to more air pollution have a higher risk of dementia.
- Mental health: Untreated depression can increase dementia risk.
Can Physical Activity Prevent Dementia?
Regular physical activity is one of the most powerful ways to protect your brain and reduce the risk of Alzheimer’s disease. In fact, engaging in regular physical activity can lower the likelihood of dementia by up to 20%. A long-term study of nearly 500 participants found that people who stayed physically active, especially before the age of 50 and throughout their lives, had a larger hippocampus and better cognitive function at age 70. The study also suggested that women may be particularly sensitive to the effects of exercise: those who were inactive across their lives showed stronger signs of early Alzheimer’s changes, while active women had more protection against these effects.
- Aerobic exercise: Aerobic exercise reduces vascular risk factors such as hypertension and insulin resistance, which are known contributors to dementia through cerebrovascular damage.
- Resistance training: Research shows that resistance training improves verbal memory and sustains the volume of the hippocampus, a key brain region involved in memory.
Can Specific Diets Influence Brain Health?
While no single food can completely prevent dementia, strong evidence indicates that overall healthy eating patterns play a significant role in reducing risk and slowing cognitive decline.
- MIND diet (Mediterranean-DASH Intervention for Neurodegenerative Delay): The MIND diet is a dietary pattern designed to protect the brain and reduce the risk of dementia. This hybrid of the Mediterranean and DASH (blood pressure-lowering) diets, designed specifically for brain health, emphasises leafy greens, berries, and whole grains. This diet may help reduce oxidative stress and inflammation, both major contributors to brain ageing and Alzheimer’s pathology.
- Ketogenic diet: Although research is limited, very low-carbohydrate diets and medium-chain triglyceride supplements have shown promising benefits for mild cognitive impairment and Alzheimer’s disease. Ketogenic diets may indirectly support cognition by improving insulin sensitivity, especially in people with type 2 diabetes, a known risk factor for Alzheimer’s disease. Ketones may also provide an alternative fuel source for brain cells, which could be especially beneficial in Alzheimer’s disease, where glucose metabolism in the brain is impaired.
Are There Supplements With Evidence?
Although food and lifestyle are the foundation of brain health, certain supplements have been studied for their potential role in reducing Alzheimer’s risk. These should never be seen as a replacement for a healthy lifestyle, but they may provide additional support when used appropriately.
- Omega-3: Found in fatty fish such as salmon, mackerel, and sardines, omega-3s are essential fats that support brain cell structure and also reduce inflammation. Multiple studies link higher omega-3 intake to slower cognitive decline and a lower risk of dementia, especially in women. For those who don’t eat fish regularly, a high-quality fish oil or algae-based vegan supplement may be helpful.
- Vitamin D: Vitamin D plays a role in brain signalling and immune function. Low vitamin D levels are common in older adults and have been associated with increased dementia risk. Supplementation may help, but dosage should always be monitored by a healthcare professional.
- Creatine: Creatine is best known for its use in sports and muscle health, but emerging research shows it also supports energy production in the brain, improving working memory and cognitive performance.
How Important is Sleep?
During sleep, the brain’s glymphatic system clears waste products, including the amyloid plaques associated with Alzheimer’s disease. Poor sleep disrupts this process, raising the risk of cognitive decline.
What can you do to reduce your risk?
While Alzheimer’s disease cannot yet be cured, research shows that prevention is possible. By focusing on lifestyle changes, we can significantly reduce our risk and protect our brains as we age. Here’s some things you can do to reduce your dementia risk:
- Improve your diet by avoiding processed foods and adopting elements of the Mediterranean or MIND diets.
- Increase your physical activity by building movement into your daily routine.
- Develop better sleep hygiene by creating a cool, dark, and quiet environment, keeping a consistent schedule, and reducing screen time before bed.
- Check health markers to ensure your blood pressure, cholesterol, and blood sugar levels are under control.
- Avoid harmful habits like smoking and excessive alcohol use.
Frequently Asked Questions (FAQ)
Can Alzheimer’s disease be completely prevented?
No, there is currently no guaranteed way to prevent Alzheimer’s. However, research shows that healthy lifestyle choices can significantly lower risk.
Are supplements necessary for brain health?
Not always. Most nutrients should come from a healthy diet, but supplements like omega-3 fatty acids, vitamin D, and creatine may be useful for some people. Always check with a healthcare professional before adding new supplements.
At what age should I start thinking about prevention?
It’s never too early or too late to start! Brain health strategies are beneficial at any age.
References
Ahlskog, et al (2011). Physical Exercise as a Preventive or Disease-Modifying Treatment of Dementia and Brain Aging. Mayo Clinic Proceedings, 86(9), pp.876–884. doi:https://doi.org/10.4065/mcp.2011.0252
Broadhouse, et al (2020). Hippocampal plasticity underpins long-term cognitive gains from resistance exercise in MCI. NeuroImage: Clinical, 25, p.102182. doi:https://doi.org/10.1016/j.nicl.2020.102182
Ghahremani, et al (2023). Vitamin D supplementation and incident dementia: Effects of sex, APOE, and baseline cognitive status. Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring, 15(1). doi:https://doi.org/10.1002/dad2.12404
James, et al (2024). The relationship between leisure time physical activity patterns, Alzheimer’s disease markers and cognition. Brain Communications, 7(1). doi:https://doi.org/10.1093/braincomms/fcae431
Jennings, et al (2020). Can nutrition support healthy cognitive ageing and reduce dementia risk? The BMJ, 369. doi:https://doi.org/10.1136/bmj.m2269
Morris, et al (2015). MIND diet slows cognitive decline with aging. Alzheimer’s & Dementia, 11(9), pp.1015–1022. doi:https://doi.org/10.1016/j.jalz.2015.04.011
Nedergaard & Goldman (2020). Glymphatic failure as a final common pathway to dementia. Science, 370(6512), pp.50–56. doi:https://doi.org/10.1126/science.abb8739
Smith, et al (2025). Creatine monohydrate pilot in Alzheimer’s: Feasibility, brain creatine, and cognition. Alzheimer’s & dementia (New York, N. Y.), 11(2), p.e70101. doi:https://doi.org/10.1002/trc2.70101