Alzheimer’s Disease (AD) is a debilitating neurological disorder that poses significant challenges to our aging global population. The incidence of Alzheimer’s is on the rise, affecting millions and placing an immense burden on health care systems worldwide (1,2). This cruel disease not only robs individuals of their memories and identities, but also evokes profound fear and uncertainty for those affected and their loved ones. Therefore, primary care providers (DC’s, ND’s, our allopathic colleagues) should all be up-to-date in the lifestyle factors that can contribute to this disease and communicate prevention strategies with patients.

One of the primary reasons I started to study functional neurology is because Alzheimer’s Disease runs in my family. The idea of my body still functioning while who I am as a person – my personality and memories – not being there, is the darkest fate I can imagine. Therefore, I continue to strive to learn as much as I can about maintaining function of the brain and keeping it healthy. I hope to impart some of this knowledge to you and provide those with a similar fear of this disease with some comfort that there are things that we can do to better our odds.

The bad news about Alzheimer’s Disease is that there is still no cure. AD is such a multi-factorial disease that attacking just one facet of its pathophysiology – drugs designed to remove protein plaques or increase the amount of our acetylcholine (our “memory” neurotransmitter) – have been deemed minimally effective (3). Therefore, prevention of this disease is very much in the natural practitioner’s wheelhouse (lifestyle and nutrition).

A gargantuan systematic review was conducted in 2020 to determine which lifestyle factors have the best evidence for preventing this awful disease. This study looked at a whopping 243 observational prospective studies that examined associations between modifiable risk factors and AD onset and 153 randomized controlled trials that tested interventions targeting these risk factors. Here I will share some (yet, not all) of the evidence-based lifestyle factors that were associated with AD via this combination of observation and experimental data (4):

Class I Factors with Strong Evidence/Level A (4):

1. Higher education: Higher education is correlated with greater cortical thickness and brain volume, which may offer resilience against Alzheimer’s pathology (5,6). This is good news for those of us at National University.
2. Cognitive Activity: Use it or lose it, I suppose. Engaging in mentally stimulating activities may help reduce AD risk by enhancing neural connections and brain plasticity, shown to delay onset of the disease (7).
3. High Body Mass Index (BMI) early in life, Low BMI late in life: Maintaining a healthy BMI in later years is protective, as it might reduce the risk of vascular diseases that contribute to AD pathology (8). The systematic review recommends screening for high BMI as a risk factor in those below the age of 65 and screening for low BMI as a risk factor in those older than 65.
4. Hyperhomocysteinaemia: Excess homocysteine, an amino acid that elevates when we aren’t getting enough vitamin B9 or B12, can lead to vascular damage and neurotoxicity, increasing AD risk (9). This is a marker that can be easily evaluated on conventional blood work.
5. Depression: Depression is associated with increased brain inflammation and cortisol levels, both of which can contribute to AD pathology (10,11). This is cyclical in nature, however, so addressing brain inflammation may also help a depressed individual as well. One should also seek out therapy to avoid this potential sequala of depression.
6. Stress: Like depression, chronic stress can elevate cortisol levels, leading to hippocampal atrophy and increased AD risk (12,13).
7. Diabetes: Diabetes can cause insulin resistance in the brain, which can contribute to the protein misfolding linked to AD pathology (14). There is such a strong link here that Alzheimer’s Disease has been coined “Type III Diabetes” (15).
8. Head Trauma: Mild traumatic brain injuries or concussions can set off a cascade of brain inflammation that increases AD risk (16, 17). Avoiding head injuries and/or getting proper care after repeated head trauma is crucial.
9. Hypertension in Midlife: Hypertension can lead to vascular damage and reduced cerebral blood flow, contributing to AD (18).
10. Manage Orthostatic Hypotension: Orthostatic hypotension can cause recurrent episodes of cerebral hypoperfusion, leading to neuronal damage (19, 20). This means a swift, proper referral for the treatment of this condition should be an utmost priority for health care providers.

Class I Recommendations with Moderate Evidence/Level B (4):

1. Physical Exercise: Don’t let the Level B rating fool you – Regular physical activity has been shown to be massively beneficial by way of promoting cardiovascular health, improving cerebral blood flow and greatly reducing inflammation. Exercise also stimulates the release of neurotrophic factors like BDNF, which support neuronal health and plasticity. Physical activity can literally increase the size of the hippocampus, the first part of the brain affected by AD (21,22). Get moving!
2. Smoking: Smoking is associated with increased oxidative stress, neurotoxicity and inflammation, all of which can contribute to Alzheimer’s disease pathogenesis (23). Just another way that smoking is bad.
3. Sleep: Good sleep hygiene is imperative, as poor sleep quality or sleep disorders, such as sleep apnea, can lead to increased amyloid-beta accumulation in the brain. Sleep is essential for the clearance of metabolic waste products and overall brain health (24,25).
4. Frailty: It is important to maintain resistance training activity into later age to avoid loss of muscle mass (called age-related sarcopenia). A decline in muscular strength increases vulnerability to stressors and can therefore accelerate cognitive decline (26,27).
5. Vitamin C: Ensuring adequate intake of Vitamin C is beneficial due to its antioxidant properties, which help protect brain cells from oxidative damage. Vitamin C also plays a role in collagen synthesis, supporting the integrity of blood vessels that supply the brain (28).

Understanding these preventive strategies and their mechanisms is pivotal in our ongoing battle against AD. The evidence-based recommendations outlined in this article offer a roadmap for reducing the risk of Alzheimer’s through modifiable lifestyle factors and risk management.

As we continue to advance our knowledge through research and education, we must remain committed to implementing these preventive measures with our patients, our families and within our own lives. By doing so, we can make significant strides in preserving cognitive health and improving the quality of life, especially for those at increased risk of Alzheimer’s Disease. If you want to learn about cognitive decline, differential diagnoses of different forms of dementia and how to catch early clinical signs of these diseases – this will be a topic of a future presentation in our Advanced Functional Neurology Club. Please reach out if you would like to be added to the email list to learn more about our club meetings.

Disclaimer: This content is not intended to be medical advice or a substitute for conventional medical treatment. Please consult with your doctor or another licensed health care professional if you feel like you are experiencing cognitive decline.

Read more NUHS blogs here.

Sources:

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