This year World Alzheimer’s Day is on the 21st September and is part of World Alzheimer’s month. The aims this year are to highlight the importance of talking about dementia and to raise awareness of how it impacts the daily lives of people affected by the condition and to challenge the stigma that surrounds it.
Dementia affects some 50 million people globally, a number that is expected to more than triple by 2050. Alzheimer’s disease is the most common form of dementia It is a neurodegenerative disorder associated with impaired cognition and accumulation of amyloid-β peptides in the brain.
The good news is that in some countries, including England, France and the United States, the proportion of older people with dementia has fallen, probably in part due to improvements in education, nutrition, health care, and lifestyle. This shows that it is possible to reduce the risk of dementia through preventative measures.
Here we’ll look at the risk factors for dementia and Alzheimer’s disease and the steps we can all take to protect our brain as we age.
According to a report by the Lancet Commission on dementia prevention, intervention and care modifying 12 risk factors over a lifetime could delay or prevent 40% of dementia cases (1). The 12 risk factors are:
- Excessive alcohol intake in mid-life
- Head injury in mid-life
- Air pollution in later life
- Less education early in life
- Mid-life hearing loss
- Social isolation
- Physical inactivity
- Diabetes later in life (65 and up).
The recommendations include:
- Aim to maintain systolic blood pressure of 130 mm Hg or less from the age of 40.
- Reduce hearing loss by protecting ears from high noise levels and use hearing aids when needed.
- Reduce exposure to air pollution and second-hand tobacco smoke.
- Prevent head injury.
- Limit alcohol intake to no more than 21 units per week.
- Stop smoking and support others to stop smoking.
- Provide all children with primary and secondary education.
- Lead an active social life into mid-life and later life.
- Reduce obesity and diabetes through diet and lifestyle measures.
Diet and Dementia
The brain is dependent on the food we eat for vitamins, minerals, amino-acids and essential fatty acids in order to function. Not surprisingly brain diseases such as dementia can be caused or exacerbated by dietary deficiencies, particularly of anti-oxidants, vitamins and minerals (2). There is some evidence linking certain dietary patterns, particularly the Mediterranean diet, with a reduced risk of dementia and depression (3).
This is backed up by research which suggests that diets with a higher intake of fruit, vegetables, legumes, olive and seed oils, fish, lean red meat, poultry and low in dairy products, processed meat and offal, are strongly associated with greater brain integrity among older adults (4)
Nutrients and Dementia
A growing body of scientific evidence suggests that increasing certain nutritional compounds in the brain may reduce the risk of Alzheimer's disease. Specific nutrients have been investigated in relation to brain health, with emerging evidence supporting protective roles for omega 3 fats, polyphenols, vitamin D and B-vitamins particularly folate, vitamin B12, vitamin B6 and vitamin B2 in slowing the progression of cognitive decline and possibly reducing the risk of depression in ageing (3).
Let’s take a look at some of the nutrients involved in brain function.
Vitamin B1 modulates cognitive performance, especially in the elderly.
Vitamin B9 (folic acid) preserves the brain during its development, and preserves memory during ageing.
Vitamins B6 and B12 are involved in the synthesis of neurotransmitters.
Vitamin B12 delays the onset of signs of dementia. Supplementation with vitamin B12 improves cerebral, cognitive and language functions in the elderly
Vitamin C acts as an antioxidant in the brain and plays a role in synaptic activity and detoxification. Doses of 130-500 mg daily are recommended to prevent dementia (5).
Vitamin D and its analogues are of interest in the prevention of neurodegenerative diseases.
Vitamin K is involved in nervous tissue biochemistry.
Iron is necessary for oxygenation and to produce energy in the brain and for the synthesis of neurotransmitters and myelin.
Magnesium affects many biochemical mechanisms vital for neuronal function and synaptic plasticity. Magnesium levels may be decreased in the brain of Alzheimer’s disease patients. Supplementation with magnesium has potential for preventing Alzheimer’s disease (6).
Zinc is involved in the transmission of neurotransmitters. Zinc deficiency is associated with Alzheimer's disease and depression. Zinc supplementation at 10-30 mg daily improves neurologic recovery rate in patients with brain injury and has a positive impact on memory (5).
Omega 3 oils – Patients with Alzheimer’s disease who consumed a combination of carotenoids with fish oil showed improvements in memory, sight and mood (7).
The Gut and Dementia
The bidirectional communication between the brain and the gut microbiota plays a key role in human health. There are many studies showing that the gut microbiota influence our brain and behaviour. Metabolites secreted by the gut microbiota may lead to inflammation and affect the cognitive ability of patients with neurodegenerative diseases (8,9). This may be due to increased permeability of the gut and blood-brain barrier induced by microbial dysbiosis.
The following supplements are worth considering to protect the brain and reduce the risk of dementia: