What is dementia?

Worldwide, around 55 million people suffer from dementia, and there are nearly 10 million new cases every year.

The number of people living with dementia is expected to double every 5 to 20 years depending on the source.

In the UK, 1 in 14 people over 65 have dementia. and in the US this number is 6 million people or approximately 1 in 50 of the total population.

In the US it kills more people than breast and prostate cancer combined.

Dementia is cognitive decline in which many mental abilities are lost. It is a neurodegenerative disorder usually characterized by the presence of amyloid plaques (also known as beta-amyloid or A-beta) and neurofibrillary tangles of neurons in the brain (also known as tau-beta).

Early symptoms of dementia can include:

  • Memory loss
  • Difficulty reading, writing, and speaking
  • Difficulty following a conversation, reasoning, calculating
  • Difficulty organizing and planning

Dementia is progressive, meaning that symptoms start out slowly and gradually get worse.

There are many types of dementia, including vascular dementia, frontotemporal dementia, Lewy bodies dementia, and others, but Alzheimer’s disease is the most common.

Alzheimer’s disease

This form of dementia, which represents 40 to 60% of cases of dementia, is marked by amyloid plaques and neurofibrillary tangles. There is growing evidence that neither is the cause of Alzheimer’s, as long believed, but Alzheimer’s disease is typically correlated with the presence of these plaques and tangles.

Alzheimer’s disease is usually diagnosed on the basis of a patient’s symptoms, which include memory loss and cognitive deficits which can start mildly but become so severe and ever-worsening that the patient loses the ability to bathe, eat or dress without assistance and is increasingly unable to care for himself or herself.

Vascular dementia

This form of dementia is caused by reduced blood flow to the brain and marked by multiple small strokes. In recent years it has been recognized that Alzheimer’s disease and vascular dementia overlap.

Lewy bodies dementia

The third most common form of dementia, after Alzheimer’s and vascular dementia. Features visual hallucinations, delusions, increased sleeping, and flinging of limbs during sleep (called REM behavioral disturbance), among other features.

Frontotemporal dementia

This is much less common than Alzheimer’s disease, and often features changes in behavior, memory problems, and difficulty speaking.

Subjective cognitive impairment (SCI)

Worsening condition that is noticeable to the individual but, in standard neuropsychological testing, still falls in the normal range.

A very intelligent individual may recognize his or her memory loss only to be told that testing shows his or her memory to be in the ‘normal’ range, but this ‘normal’ actually represents a decline from the person’s earlier ability.

Even at this early stage, PET scans and cerebrospinal fluid will often be abnormal, and MRI may show some shrinkage of brain regions, SCI often lasts a decade or so before progressing to MCI.

Mild cognitive impairment (MCI)

This typically follows SCI. Neuropsychological tests show that memory, organizing, speaking, calculating, planning, or other cognitive abilities are abnormal, but the person is still able to perform the so-called activities of daily living, such as dressing, eating, and bathing.

MCI does not inevitably progress to Alzheimer’s disease, but in many people Alzheimer’s disease will follow within a few years.

A functional medicine approach

Conventional medicine looks at dementia as a problem of brain plaques, however this approach has not yielded good results, and removing amyloid plaques does not translate into improvements in cognition.

A functional medicine, or precision medicine approach, which diagnoses and treats the root causes of dementia and focusses on the whole body rather than just the brain, has been shown to have better outcomes.

There is a growing body of evidence that shows that dementia is actually the result of a protective response in the brain, arising when the brain responds as it should to certain threats.

Indeed, dementia seems to be the result of the brain trying to protect itself from three metabolic and toxic threats:

  • Decline and shortage of supportive nutrients, hormones and other brain-supporting molecules
  • Toxic substances such as metals or biotoxins (poisons produced by microbes such as mold)

Once we recognize that dementia is what happens when the brain struggles to:

  • defend itself against inflammation
  • function despite a shortage of beneficial compounds
  • fight an influx of toxic substances

then the optimal way to prevent and treat the disease becomes clear:

  • identify which of the many potential contributors to these three classes of threats a particular patient’s brain is responding to
  • remove these specific contributors
  • help it fend off the remaining attackers and regenerate

Cognitive decline can be prevented and in many cases reversed. 

Genetics affect your risk for dementia, but your fate is by no means written in your DNA.

Personalized therapeutic programs can prevent and reverse cognitive impairment even in people carrying the ApoE4 gene (ApoE is short for apolipoprotein E, a protein that carries lipids), one of the genetic risk factors for dementia. 

Dale Bredesen, MD is a pioneering Neurologist who has researched and written about using a Functional Medicine approach to reversing Mild Cognitive Impairment (MCI) and early Alzheimer’s (AD). According to Dr. Dale Bredesen’s ReCODE (Reversal of Cognitive Decline) protocol, the fundamentals that must be addressed in order to reverse cognitive decline and reduce the risk for future decline are: 

The ReCODE program is personalized. The earlier you start treatment, the greater your chance for complete reversal.

Solutions: 10 ways you can support your brain health

Correcting your nutrition is the first step in preventing and avoiding dementia, as our diet has a huge impact on the three key contributors to dementia — inflammation, lack of nutrients and trophic factors, and toxins.

Focus on eating:

  • anti-inflammatory foods such as colourful vegetables, fruits, oily fish, healthy fats and avoid inflammatory foods such as refined sugar based foods
  • gut healthy foods which improve the health of the microbiome and preserve the integrity of the intestinal lining and the blood-brain lining, thereby improving absorption of nutrients and reducing inflammation from a permeable intestinal and blood-brain lining
  • nutrient dense foods which encourage the regeneration of brain cells
  • clean foods that have fewer pesticides, heavy metals and other chemicals
  • detoxifying and anti-oxidant foods

Focus on balancing your blood sugar and improving insulin sensitivity:

  • eat meals which have a balance of protein, fats and complex carbohydrates which will help generate a consistent source of energy to support your brain and prevent cognitive decline
  • eat at regular intervals
  • practice intermittent fasting (12 to 16 hours fast between your last meal of the day and your first meal of the next day) as this will improve insulin sensitivity which is important for healthy cognition

Focus on including nutrients for optimal brain health:


Found in:

  • Fish
  • Caviar
  • Shellfish
  • Algae


Found in:

  • Eggs
  • Liver
  • Fish
  • Nuts
  • Chickpeas

Vitamin B12

Found in:

  • Liver
  • Clams
  • Sardines
  • Eggs
  • Fortified nut milks

Vitamin D

Found in:

  • Sunshine
  • Oily fish
  • Liver
  • Egg yolks
  • Mushrooms


Found in:

  • Liver
  • Oily fish
  • Caviar
  • Kale
  • Sweet potatoes


Found in:

  • Oysters
  • Tofu
  • Nuts
  • Seeds
  • Grass-fed beef

Key deficiencies of these nutrients have been found in patients with Alzheimer’s disease.

A carefully chosen nutrient-dense diet, consisting of a wide variety of foods, is your best defense against developing a deficit. If your diet is limited, consider supplementation to ensure that your brain has the best chance of optimal performance.

Read more about how to correct your nutrition and supplement.

Many hormones contribute to optimal cognitive function, in particular by supporting synapse formation and maintenance, and when their levels drop, due to ageing, stress, inflammation, toxins, or lack of co-factors, cognition can decline.

In order to prevent or reverse cognitive decline, it is critical to optimize hormone levels:


  • thyroid function is suboptimal in many people with cognitive decline

Estradiol and progesterone

  • for women especially, these sex hormones are essential to brain health


  • optimal levels of testosterone support synaptic maintenance

Adrenal hormones

  • optimise levels of cortisol, pregnenolone, and DHEA

For better brain health, optimize your thyroid function, estradiol, progesterone and testosterone levels, and balance your cortisol and adrenaline levels.

Read more about how to balance your hormones.

One of the most important contributors to dementia is inflammation. Resolving inflammation is therefore critical to reversing cognitive decline.

Remove the causes of the inflammation, such as:

  • Leaky gut and an unhealthy gut microbiome
  • A diet high in simple carbohydrates or trans fats, sugar, gluten, dairy and grains
  • Chronic infections such as Lyme disease or viruses such as Herpes and EBV
  • Biotoxins such as molds (eg: Aspergillus) and other toxins such as heavy metals and pesticides
  • Poor oral hygiene which can breed bacteria which can cause neuroinflammation
  • Sinus infections

Read more about how to reduce inflammation.

Address potential infections, optimize your immune system’s ability to destroy pathogens and reduce the chronic inflammation that results from constantly fighting viruses such as Epstein Barr and Herpes, and bacterial infections such as Lyme.

Exercise is one of the best validated ways we have to increase the production of new neurons in our brain, and to help prevent dementia. We can reduce the risk of Alzheimer’s by up to 45% with exercise.

The most relevant benefits of exercise for cognition:

  • Exercise reduces insulin resistance, which is a key player in Alzheimer’s disease
  • It increases ketosis, which among other effects, increases the production of BDNF (brain-derived neurotrophic factor) which in turn regenerates brain cells
  • It increases the size of the hippocampus, a key region for memory and one that shrinks in Alzheimer’s disease
  • It improves vascular function, which is crucial for neuronal and synaptic health
  • It reduces stress, a key trigger of Alzheimer’s-promoting inflammation
  • It improves sleep, another necessity for cognitive health
  • It increases the survival of newborn neurons that are created during neurogenesis
  • It helps balance hormones
  • It has been shown to improve gut health

The optimal exercise for cognition is a combination of aerobic exercise, such as jogging or walking, spinning or dancing, with weight training, preferably at least four or five days per week, for 45 to 60 minutes in total each day.

Read more about how to exercise right.

Sleep affects cognitive function through multiple mechanisms:

  • During sleep, the immune system of the brain, the glymphatic system, helps to detoxify and cleanse the brain
  • Sleep is associated with reduced formation of amyloid plaque
  • We don’t eat when we’re asleep, and fasting improves our insulin sensitivity and triggers healthy autophagy, or programmed cell death
  • During sleep, our brain cells undergo autophagy, the process of ‘self-eating’ that recycles cellular components like damaged mitochondria and misfolded proteins, improving cellular health
  • During sleep, our growth hormone is active, repairing and creating new brain cells 

Sleep deprivation also increases the risk of obesity, diabetes, and cardiovascular disease, all risk factors for Alzheimer’s disease.

To avoid or reverse cognitive decline, optimal sleep is indispensable.

Optimize your sleep:

  • Treat any sleep issues you might have such as sleep apnea (a known contributor to dementia) and restricted airways syndrome
  • Try to get as close to eight hours of sleep per night as possible
  • Practice good sleep hygiene

Read more about how to sleep better.

One of the key contributors to dementia is a heavy toxic load. Whether from biotoxins such as moulds, or pesticides and other chemicals, or heavy metals, there is a correlation between high toxic load and increased dementia, possibly due to the neuroinflammation they can cause.

In order to prevent and reverse dementia, it is essential to reduce your exposure to toxins and metals (including dental exposure) and optimise your detoxification.

Read more about how to detoxify. 

Your brain and gut are connected through the gut-brain axis. A healthy gut contributes to brain health by protecting the integrity of both the intestinal lining and the blood-brain barrier, thus decreasing the risk of neuroinflammation.

Healing your gut reduces systemic inflammation, improves nutrient absorption, enhances immune responses, and supports an optimal microbiome, thus contributing to the production of healthy hormones and neurotransmitters.

Making sure your gut is healthy is a key tactic in the prevention and reversal of cognitive decline. The first step is to understand the potential triggers, such as sugar, gluten, dairy, alcohol, antibiotics, pesticides and so on, then eliminating or minimizing these.

Eating fibre rich whole foods and a balance of proteins, good fats and complex carbohydrates is also healing to your gut, as is eating prebiotic and probiotic foods and foods which are nutrient dense and high in polyphenols. 

Read more about how to heal your gut.

Stress is one of the most important contributors to cognitive decline. High levels of cortisol damage neurons, especially in the hippocampus, making chronic stress an important contributor to hippocampal damage and thereby cognitive – and especially memory – decline. However, a rapid reduction in cortisol can also lead to the loss of neurons in the hippocampus.

Chronic stress can lead to dysfunction of the HPA axis, which can lead to either excessive cortisol and adrenaline, or insufficient stress hormones which then struggle to meet the demands from stresses such as infections, toxins, or lack of sleep. Both excessive and insufficient stress hormones can further exacerbate cognitive decline.

Stress reduction is critical to cognitive optimization. Meditation, yoga, breathwork, laughter, massages, music, movement and hanging out with people you love and who love you, are great ways to reduce stress. There is good evidence that a daily meditation practice is protective against cognitive decline. 

Read more about how to manage your stress.

Mental exercises can improve cognitive function. You only need 10 or 20 minutes per day, five days per week, to see improvements. There are many online programmes and apps that can help improve brain function.

Read more about how to train your brain.