Alzheimer's prevention and support: Understanding the biological drivers of cognitive decline
- Michaela Newsom
- Feb 2
- 7 min read
Updated: Jun 10
KEY TAKEAWAYS
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Table of contents
What causes Alzheimers?
When we talk about Alzheimer's, it’s easy to imagine brain cells simply “dying off.” In reality, cognitive decline is far more complex.
Current research suggests that Alzheimer's develops gradually through a combination of biological changes that affect the brain's ability to function, repair itself, communicate effectively, and generate energy. These changes can begin many years before symptoms become noticeable.
Scientists now understand that inflammation, impaired blood flow, insulin resistance, nutrient deficiencies, environmental exposures, and previous brain injuries can all contribute to cognitive decline. Rather than being caused by a single factor, Alzheimer's often develops when several of these processes interact over time.
Understanding these underlying drivers is important because many are potentially modifiable. This creates opportunities for both Alzheimer's prevention and support long before a formal diagnosis is made.
A Functional Medicine Perspective on Dementia
Neurologist Dr Dale Bredesen’s has proposed a frame that groups Alzheimer's into several biological patterns based on potential underlying contributors. Whilst these categories are not reconised as formal medical diagnoses, his work helps us understand why this happens and identifies the different biological pressures that push the brain into a protective—but ultimately harmful—state. His work outlines six dementia subtypes, each with their own underling root cause.
1. Inflammatory (Hot) Alzheimer's
When the brain is stuck in defence mode
Inflammation is a normal part of the body's immune response. However, whne inflammation becomes chronic, it can have damaging effects on brain health.
Inflammatory dementia develops when the immune system is constantly activated. The brain interprets this as a sign of danger and shifts its priorities from learning and memory to protection and survival.
Over time:
Immune chemicals damage synapses (the connections between brain cells)
Amyloid plaques increase as a defensive response
Memory and concentration gradually decline
Common triggers include chronic infections, gut imbalance, autoimmune conditions, and long-term stress. Importantly, inflammation often begins years before noticeable memory problems appear.
Growing evidence suggests that neuroinflammation plays an important role in the development and progression of Alzheimer's Disease and other dementias.
Support strategies include:
Prioritise an anti-inflammatory dietary pattern such as the Mediterranea or MIND diet
Optimise sleep quality
Manage chronic stress
Support gut health through a diverse fibre rich diet
Engage in regular physical activity
2. Atrophic (Cold) Alzheimer's
When the brain lacks the nourishment it needs to thrive
The brain requires a constant supply of nutrients, hormones and growth factors to maintain healthy structure and function. This subtype of Alzheimer's occurs when the brain is not receiving enough of these factors which causes brain cells to shrink rather than inflame, connections to weaken due to lack of support and repair processes to slow down.
Hormones such as oestrogen, testosterone, thyroid hormone, and vitamins B12 and D act like “fertiliser” for the brain. When levels fall—particularly during midlife transitions—the brain becomes more vulnerable to decline.
Support strategies include:
Assess and address nutrient deficiencies
Maintain adequate protein intake
Optimise vitamin D status
Follow a nutrient dense dietary pattern of whole foods
Regular exercise to boost levels of BDNF (brain-derived neurotrophic factor, aka miracle-gro fro the brain).
3. Glycotoxic (Sweet) Alzheimer's
When the brain struggles to access energy
The brain relies heavily on a stable energy supply and it's preferred fuel is glucose. In glycotoxic dementia, long-term blood sugar imbalance and insulin resistance prevent brain cells from accessing energy efficiently.
As a result, brain cells become energy-starved, insulin signals increase amyloid plaque production and inflammation quietly increases.
Some researchers to describe Alzheimer's diease as having characteristics of "brain insulin resistance" and refer to Alzheimer's as 'Type 3 diabetes'.
Risk factors for this subtype of Alzheimer's is strongly associated with metabolic conditions such as pre-diabetes, type 2 diabetes, and abdominal weight gain, even in people who appear otherwise healthy.
Support strategies include:
Maintain healthy blood glucose levels
Engage in regular exercise
Consume adequate fibre
Avoid highly processed and sugary foods
Address insulin resistance early
4. Toxic Alzheimer's
When the brain is overwhelmed by harmful exposures
The brain is vulnerable to certain environmental toxins and pollutants. Research suggests that long term exposure to toxic substances can cause inflammation and oxidative stress in the brain. These toxins interfere directly with brain cell function by disrupting neurotransmitters, damaging cell membranes and increasing oxidative stress.
Sources may include mould toxins, heavy metals, air pollution, and certain chemicals. In this subtype, memory loss may appear suddenly or progress rapidly, often without obvious inflammation or metabolic issues.
Support strategies include:
Improve indoor air quality
Minimise exposure to tobacco smoke
Address significant water damage and mould issues promptly
Choose organic, whole foods where possible to reduce exposure to food related contaminants
5. Vascular Alzheimer's
When blood flow can’t meet the brain’s demands
The brain needs a constant supply of oxygen and nutrients delivered through the vascular system. Vascular dementia occurs when circulation is compromised, even subtly. Conditions that damage blood vessels can gradually impair brain function and increase Alzheiemr's risk.
Important vascular risk factors include:
High blood pressure
Elevated cholesterol
Raised homocysteine
Smoking
Physical inactivity
Type 2 diabetes
In fact, many of the same factors that increase the risk of heart disease, also increases the risk of dementia. The damage often accumulates silently until memory, attention, or processing speed begins to suffer.
Support strategies include:
Monitor blood pressure regularly
Engage in aerobic and resistance exercise
Stop smoking
Follow a heart healthy dietary pattern
Manage cardiovascular risk factors - improving cardiovascular health is one of the most evidence based approaches to dementia prevention.
6. Traumatic Alzheimer's
When past head injuries leave a lasting imprint
Traumatic Alzheimer's is linked to previous head injuries, even those that seemed mild at the time. Research has found associations between previous head injuries and increased risk of later life cognitive decline and dementia. Each impact can trigger inflammation and microscopic damage that doesn’t fully resolve. This can lead to persistent neuroinflammation, structural damage to neurons, abnormal protein accumulation and altered brain connectivity.
This helps explain why cognitive decline can appear decades after sports injuries, falls, or accidents and the risk maybe higher in individuals with repeated head impacts such as contact sports atheletes.
Support strategies include:
Always seek assessment following head injuries
Follow rehabilitation recommendations carefully
Avoid repeated head trauma where possible
Prioritise sleep
Why Understanding These Mechanisms Matters
The brain is constantlly responding to signals from its environment and the rest of the body. When it perceives ongoing threat—whether from inflammation, lack of support, toxins, or poor blood flow—it shifts into a protective state that prioritises survival over memory. Many of these signals are modifiable. By identifying which pressures are affecting the brain, it becomes possible to reduce them and support cognitive resilience.
Most people don’t fit neatly into just one subtype. Cognitive decline is often a blend of several mechanisms, which is why a personalised, whole-person approach is so important. Understanding why the brain is struggling allows for targeted strategies that support long-term brain health—often long before dementia is diagnosed.
While aging remains the greatest risk factor for dementia, research increasingly shows that lifestyle, nutrition, cardiovascular health and environmental factors also influcene cognitive health.
If you are concerned about your memory, or would like to take a proactive approach to brain health, a personalised nutrition plan could be just the thing. Book a complimentary introductory call to find out how a personalised nutrition could help protect your brain in the future.
Frequently Asked Questions
Can dementia be prevented?
There is currently no guaranteed way to prevent dementia. However, evidence suggests that addressing modifiable risk factors such as high blood pressure, physical inactivity, smoking, obesity, poor diet, and diabetes may significantly reduce risk.
What is the strongest evidence-based approach for dementia prevention?
Regular physical activity, cardiovascular risk management, smoking cessation, high-quality nutrition, social engagement, and lifelong learning have some of the strongest evidence for supporting brain health.
Does inflammation cause dementia?
Inflammation alone does not cause dementia, but chronic neuroinflammation is increasingly recognised as an important contributor to several neurodegenerative diseases, including Alzheimer's disease.
Is Alzheimer's disease the same as dementia?
No. Dementia is an umbrella term describing symptoms that affect memory, thinking, and daily functioning. Alzheimer's disease is the most common cause of dementia.
Can nutrition help support brain health?
Yes. Research consistently shows that dietary patterns such as the Mediterranean and MIND diets are associated with better cognitive health and may help reduce dementia risk.
References
Livingston G, Huntley J, Sommerlad A, et al. Dementia prevention, intervention, and care: 2024 report of the Lancet Standing Commission. The Lancet. 2024.
Jack CR Jr, Bennett DA, Blennow K, et al. NIA-AA Research Framework: Toward a biological definition of Alzheimer's disease. Alzheimer's & Dementia. 2018;14(4):535-562.
Aisen PS, Cummings J, Jack CR Jr, et al. On the path to 2025: Understanding the Alzheimer's disease continuum. Alzheimer's Research & Therapy. 2017;9:60.
Kivipelto M, Mangialasche F, Ngandu T. Lifestyle interventions to prevent cognitive impairment, dementia and Alzheimer's disease. Nature Reviews Neurology. 2018;14(11):653-666.
Ngandu T, Lehtisalo J, Solomon A, et al. A 2-year multidomain intervention of diet, exercise, cognitive training and vascular risk monitoring versus control to prevent cognitive decline in at-risk elderly people (FINGER trial). The Lancet. 2015;385(9984):2255-2263.
Livingston G, Sommerlad A, Orgeta V, et al. Dementia prevention, intervention, and care. The Lancet. 2020;396(10248):413-446.
Morris MC, Tangney CC, Wang Y, et al. MIND diet associated with reduced incidence of Alzheimer's disease. Alzheimer's & Dementia. 2015;11(9):1007-1014.
De la Monte SM, Wands JR. Alzheimer's disease is type 3 diabetes—evidence reviewed. Journal of Diabetes Science and Technology. 2008;2(6):1101-1113.
Heneka MT, Golenbock DT, Latz E. Innate immunity in Alzheimer's disease. Nature Immunology. 2015;16(3):229-236.
Iadecola C. The pathobiology of vascular dementia. Neuron. 2013;80(4):844-866.
About the Author
Michaela Newsom, Registered Nutrtitional Therapist, mBANT, rCNHC
Michaela is a women’s health expert with a specialist interest in the impact of menopause on the female brain. Her mission is to empower women to optimise their cognitive function and mental wellbeing throughout life with a special focus on the challenges that take place during perimenopause, menopause and beyond.
With a Postgraduate qualification in Personalised Nutrition and advanced Functional medicine training with IFM and the Kharrizian Institute Michaela has expertise spanning hormones, brain health, cognitive function and mood disorders.
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