Dementia is usually diagnosed when there is an impairment of a person’s ability to carry out daily activities for more than six months. Alzheimers disease (AD) is the most common form of dementia, affecting 62%, of those suffering with dementia, followed by vascular dementia, affecting 17%.
There are currently 850,000 people with dementia in the UK and this is predicted to increase to 1 million by 2025 and 2 million by 2050. However, as many people remain undiagnosed – as many as 53% in Europe – we can likely double the official numbers. The cost of dementia in the UK is over £26 billion and this is expected to double over the next 20 years and it costs more than cancer and chronic heart disease combined.
Familial AD (genetically passed on) is very rare, affecting only about 3% of cases and literature shows that there are a number of environmental factors which influence the risk of developing AD. These include midlife obesity, high blood pressure, hyperlipidaemia, Diabetes/insulin resistance, Vitamin B deficiencies and low levels of an omega 3 fatty acid called DHA. All of these factors have a stronger influence on the fate of our brains than genes and this is backed up by studies which have shown rates of AD increase when populations adopt Western style diets.
In AD, there is a progressive loss of whole brain volume, but especially in the hippocampus region. The hippocampus plays a role in the consolidation of information from short term to long term memory and in spatial memory which enables navigation and in AD there is a 20-25% loss of volume in this area of the brain.
It is estimated that it takes about twenty years to accumulate brain damage before AD presents itself clinically and there are certain diet and lifestyle factors that can be modified to help prevent the development of dementia.
Advanced glycation end products (AGEs) are compounds that form within the body when sugars attach to protein molecules and these can form rapidly. These AGEs then attach to receptors in our bodies and cause widespread inflammation. This results in the production of more receptors to receive more AGEs, thus creating more inflammation. High levels of AGEs have been found in the brains of deceased AD patients. Although AGEs are found in most foods, the main and highest sources of AGEs in the diet are meat and the quantities are influenced by cooking methods. For example, a raw apple contains 13 units and a baked apple has 45 units. However, a boiled hot dog has 6,700 units and a grilled hot dog more than 10,000 units. Highly processed foods contain high amounts of AGEs and high intakes of sugar encourage the formation of more, therefore we need to look at reducing, or better still avoiding, these types of foods.
Foods that are thought to be beneficial for brain health include:
● Berries – these fruits have a high content of flavanoids called anthocyanin, which have a greater antioxidant capacity than Vitamin C or E.
● Coffee – this stimulates the production of the neuroprotective acetylcholine (a neurotransmitter)
● Unprocessed cocoa – this relaxes arteries and lowers the risk of stroke.
● Fibre – a meta analysis and systematic review in 2013 concluded that for every 7g of fibre eaten daily, there is a 7% reduced risk of stroke. This is significant as with a history of stroke there is almost a 70% increased risk of developing dementia and following a recent stroke, the risk is doubled.
Studies have shown that exercise enhances connectivity throughout the brain and as this can occur into older age it is never too late to become active. Exercise seems to be the most important factor when it comes to growing more brain cells, particularly in the hippocampus. How?
Exercise increases levels of brain growth factors which promote the growth and health of brain neurones. An example is brain derived neurotrophic factor (BDNF) which is critical for new memory formation and increases threefold with aerobic exercise. Exercise also improves vascular health by regulating blood pressure and promoting the growth of new blood vessels. A randomised control trial by Erickson et al, 2011, looked at the effects of moderate aerobic exercise (brisk walking of 40 minutes three times weekly, gradually built up from 10 minutes three times weekly) on 120 adults aged 55-80. The control group were advised to do only stretching. After 1 year, the exercise group had increased levels of BDNF and had increased their hippocampus volume by 2%, effectively reversing age related volume loss. They also had increased spatial memory.
These results demonstrate that not only is exercise neuroprotective but it is not too late to start an exercise regimen later in life if you would like to enhance cognition and build brain volume. Current guidelines for exercise are 150 minutes of moderate aerobic exercise weekly, 2 or more sessions of strength training (this can be done at home with light weights/sit-ups/press-ups/squats) and trying to incorporate more movement into our daily lives – for example, getting off the bus a few stops early or walking up the stairs at work rather than getting the lift.
Short bouts of stress are needed for survival, however chronic, uncontrolled stress leads to a range of pathophysiological changes in our bodies, resulting in increased cortisol (a stress hormone) which increases AD risk, insulin resistance, inflammation and impairs the immune system. It has also been shown to reduce BDNF. People with higher cortisol levels have reduced hippocampus volume and poor memory.
Chronic stress can also lead to weight gain, high blood pressure, anxiety and depression and unhealthy behaviours such as addictions, all of which influence brain health. Our modern day lives are getting busier and busier and the constant checking of our phones, social media, emails etc place huge amounts of stress on our brains and has been shown to affect working memory in older people. Finding ways to relax is essential and meditation has been shown to have numerous benefits. One such benefit is that meditation cultivates concentration and focus, these being the first cognitive domains to be affected by dementia.
Meditation does not have to take long – even just sitting for five minutes and concentrating on each inward and outward breath will enable you to focus on the here and now, will regulate your breathing, lower your blood pressure and enable a sense of calm.
Chronically disturbed sleep increases the risk of many chronic diseases, including AD. Brains of sleep-deprived people have less volume and it is known that even one night of poor sleep can affect executive function, concentration and decision making. Restorative sleep (7-8 hours) has significant effects: during the deep phase of sleep, the brain clears toxins accumulated during a busy day and consolidates new memories. Better sleep is also associated with increased BDNF levels and brain cell restoration.
Tips for a better night’s sleep include avoiding caffeine from lunch time, avoiding strenuous exercise in the evenings, keeping the bedroom free of blue lights from phones and tablets, keeping the heating down in the bedroom, avoiding eating too close to bedtime, having a warm bath before bed and using natural sleep aids such as lavender pillow spray.
Challenge your brain:
It is commonly felt that doing puzzles, crosswords and “brain training” computer games can lower our risk of dementia. However, although these do provide benefits, they only challenge particular parts of our brains. For example, sudoku challenges our mathematical centre in the posterior parietal region of the brain, whereas a crossword challenges the language centres. To provide greater protection from neurodegenerative disease, we should be doing more complex challenges which activate multiple areas of our brains. These include learning a new language or musical instrument, learning how to dance or mentoring others in your field of expertise. These will all help your brain to become more resilient.
This is the most complex cognitive activity that can be recommended. We are fundamentally sociable creatures and isolation has been shown to have multiple negative effects on our health. Interaction with others engages multiple areas of the brain, improves mood and wellbeing and reduces loneliness.
The first randomised control trial to determine if early AD can be reversed by a comprehensive lifestyle programme is currently being conducted by Ornish et al. The programme includes providing a whole food plant based diet, moderate exercise, stress management and psychosocial support and is of 40 weeks duration, with 100 participants. It is an exciting study and I look forward to reading the published article.