Can dementia be prevented?
There is no evidence to suggest that dementia can be prevented by any one medication or activity. However, there are a lot of strategies, which are referred to as “successful ageing strategies”, that may reduce the chances of developing dementia.
Regular aerobic exercise has been associated with a lower risk of developing dementia. Aerobic exercise is any exercise that will increase your heart rate such as brisk walking, running, swimming and most sports. Exercise has a well-established link with reducing the risk of heart disease and heart attacks and the principle for stroke is the same (see stroke page). In this way exercise will reduce the risk of strokes and vascular dementia. Exercise also reduces the chance of developing other forms of dementia- this is because when we exercise the blood flow to our brains is significantly increased and this potentially allows for the development of new blood vessels and new nerve cells. However, the exercise must be regular and must be maintained. There is not much value to doing sporadic exercise every few weeks or months. The recommendation would be 30 minutes of moderate intensity exercise on most days per week. While for some this is the norm for others it may seem insurmountable. However, starting gradually and increasing the amount and intensity every week will get you up to this level without too much difficulty. While aerobic exercise is the most beneficial type of exercise resistance or strength training is also very useful. Studies have shown that regular resistance training will improve overall functioning and tasks such as walking, climbing stairs, getting up from the floor and putting on socks. A combination of both resistance and aerobic exercise will have the greatest positive impact upon memory function. Again the key here is consistency over long periods of time so introducing a daily routine incorporating both types of exercise is the ideal goal.
People are often very interested to know if there are dietary changes that can reduce the chance of developing dementia. And the good news is that there is! Studies have shown that adhering to diets such as the Mediterranean diet and DASH (Diet Approaches to Stop Hypertension) can reduce the chances of developing dementia. A recent enough study was carried out in Chicago by researchers dedicated to dementia prevention. They evaluated the diets of over 900 people aged 58-98 to try and establish the dietary components that were associated with a reduced chance of developing dementia. They came up with what is referred to as the MIND diet (Mediterranean-DASH Intervention for Neurodegenerative Delay) and this is a combination of the Mediterranean and DASH diets. The salient features are as follows:
- Brain friendly food groups include leafy green vegetables, other vegetables, nuts, berries, whole grains, beans, fish, poultry, olive oil and wine (in moderation).
- Unhealthful food categories are red meats, fried and fast foods, butter and stick margarine, cheese, pastries and sweets.
- Eating the diet consistently over time confers the greatest benefit
- The reason all of the brain healthy foods are considered as such are because they contain high levels of folate, vitamin B12, anti-oxidants and omega oils. All of these are necessary for brain health and growth. Anti-oxidants are what clears up the toxic waste products of energy formation that happens in everyone. Blueberries (and strawberries) were found to have the highest amount of antioxidants and this is why they form a big part of this diet. Tomatoes also contain a potent anti-oxidant called lycopene. Tomatoes provide more lycopene in their cooked rather than raw state. The green leafy vegetables and legumes are high sources of folate and vitamin B12 and oily fish such as salmon contains high levels of omega oils. Light to moderate consumption of wine is also linked to a lower risk of dementia. This is because wine (especially red wine) contain anti-oxidants and can increase the levels of good cholesterol. However, the most important point is that it is moderate intake defined as no more than one glass of wine per day. Higher levels of consumption are toxic and linked to increased chances of developing dementia.
In recent years the association between sleep characteristics and the risk of dementia has received a lot of attention. Good quality sleep is crucial for overall day-to-day functioning and is increasingly thought to be associated with preserved memory function over time. Sleep is broadly differentiated in to REM (rapid eye movement) or dreaming sleep and non-REM or deep sleep. Deep sleep is thought to be very important for your body to renew or repair itself and REM sleep is thought to be very important for learning and memory- both of these have been proven in clinical studies. The link between sleep and Alzheimer disease is thought to relate to the fact that deep sleep can clear the brain of unwanted proteins that deposit in the brains memory centres to cause Alzheimers disease. And following on from that if you do not get sufficient deep sleep you may be more susceptible to the abnormal protein deposits associated with Alzhemiers disease- at least this is the current theory. REM sleep is known to allow consolidation of memories and learning. Therefore, efforts to improve the quality of sleep are well worthwhile. There are several habits that many people have that are associated with poor sleep:
- Frequent daytime napping
- Spending too much time in bed
- Insufficient daytime activities
- Late evening exercises
- Insufficient bright light exposure during the day
- Excess caffeine
- Late heavy evening meals
- Watching TV late at night or in bed
- Excessive alcohol consumption
- Bedroom being too noisy, too warm or too bright.
There are, however, many ways of improving your sleep quality and these are referred to as sleep hygiene tips:
- Develop a sleep ritual- 30 minutes of relaxation before bed, hot bath before bed
- Make sure your bedroom is restful and comfortable
- Go to bed only if you feel sleepy
- Avoid heavy exercise 2 hours before bed
- Avoid caffeine, nicotine and alcohol in the evening time
- Do not watch TV in bed
- If you cannot fall asleep leave the bedroom and return when sleepy
- Maintain stable bedtimes and rising times even at weekends.
- Avoid day time napping. If you do nap limit it to 30 minutes and do not nap after 2pm.
- Meditations such as mindfulness meditation may help you fall asleep- the idea is to bring you in to the present moment and focus less on concerns and anxieties that are preventing you from falling asleep.
- Some people find listening to soothing white noise or pink noise can help them fall asleep.
- Try keeping a sleep diary for about 2 weeks. Note the quality of your sleep, what time you went to bed and got up, any ongoing stress that you were under, when and how long you exercised for and when you last ate and last drank caffeine that day- this may give a clearer picture as to which of the above tips applies most to you.
There is increasing evidence that exposure to chronic stress has a negative impact upon cognitive and memory function. When you are experiencing stress your body releases a hormone called cortisol. In the immediate stages of stress this hormone is what prepares you to fight the stress. It allows your heart rate to increase, your lungs to take in more oxygen and your blood flow increases among other things to allow you to cope with the stressor. However, when stress becomes chronic you will continue to release the cortisol but the receptors in your body become less sensitive to this. Eventually this leads to weakening of your immune system and this is how chronic stress causes illness. Whether or not this actually leads to dementia is as yet unknown. However, measuring stress in individuals is difficult because everybody has a variable resilience and response to stress. Stress is known to lead to increased risk of heart disease, high blood pressure and diabetes and each of these can lead to an increase in the vascular form of dementia.
Even though the link between stress and dementia is not definitively established identifying and treating stress is still likely to have an overall positive impact on your ability to function. Stress will negatively impact the quality of your sleep, may make you too tired to exercise and may lead to binge unhealthy eating- and, as above, all of these are important in trying to prevent dementia. Therefore, identifying stress and reducing stress in your life is a worthwhile endeavour.
- Here are some stress reducing tips:
- Firstly identify the sources of stress in your life
- Address triggers of stress
- Establish your own boundaries
- Use relaxation techniques such as mindful meditation
- Rely on close family and friends who want to support you
There is increasing evidence to suggest that higher levels of engagement in cognitively stimulating leisure activities in late life lowers the risk of developing dementia. The rationale being that challenging the brain and keeping it active it allows for development of what is referred to as a “cognitive reserve” and this essentially means that your brain is more capable of coping with brain changes that occur in dementia. The greater the variety of the hobbies and taking up brand new hobbies appears to have the greatest benefit. This may be because new hobbies are more challenging to the brain and so allow more of this cognitive reserve to build up.
- Examples of activities that exercise the brain:
- Listening to the radio
- Taking a course
- Taking up a new language
- Artistic hobbies
- Cooking and baking- new recipes
- Board games
- Crossword puzzles
A greater level of social interaction that someone engages in has been linked with a lower risk of developing dementia. The theory underlying this is similar to the theory underlying the association between new hobbies and lower dementia risk as described above. Even the most basic of social interaction requires brain stimulation. Examples of how to increase your level of social interactions are:
- Join clubs such as a walking club or dance classes (will both increase physical activity and social interaction) or a bridge or book club (will exercise the brain and increase social interaction)
- Volunteer in community groups
- Stay active in the work place.
These successful ageing strategies have not been definitively proven to prevent dementia- as this is quite a difficult thing to prove- but there have been a lot of positive associations made for each of these. They all lead to a better lifestyle lowering the risk of things like high blood pressure, diabetes, heart attacks and stroke. And all the evidence is pointing to their potential for prevention of memory problems and dementia.