Dementia is one of the foremost health challenges for this century as more than 50 million people worldwide suffer from dementia and the number is projected to triple by 2050. As ageing is associated with cognitive decline, and in consequence the risk of dementia, prevention of cognitive impairment is imperative. For those who fear developing dementia or have a family member with cognitive decline or dementia (with a potential genetic predisposition), this article will provide the best ways to prevent these serious brain health disorders.
Although there is no cure for dementia, studies have indicated that greater brain health was increased by reduced exposure to dementia risk factors and brain resilience by increased exposure to protective factors. Exposure to factors that protect your brain resiliency (called reserve-enhancing factors), such as physical exercise, intellectual stimulation, and leisure activities (environmental factors), over the lifespan, are known to be associated with a reduced predisposition of developing dementia in late life. Which factors are important to prevent dementia?
The protective factor of your "cognitive reserve"
The concept of cognitive reserve is that the more brain reserve a person has, the less likely they are to develop dementia. More importantly, the ability to maintain cognition and function at a high level in advanced age is due to cognitive reserve. The greater the reserve a person has, the longer it takes for symptoms of dementia to develop and/or the less severe that they will be when they do occur. This condition is exemplified by studies showing how cognitively healthy individuals can tolerate more neuropathy without a functional loss than people without brain reserve.
Two main factors to increase your cognitive reserves
Your capacity for cognitive adaptability and flexibility
A common concept that is often mentioned in relation to cognitive reserve is the flexibility of thinking. This means being open to new information, ideas, and challenges. A person with a high capacity for cognitive adaptability and flexibility will be better able to adjust to changes in the environment that occur over time as they age, as well as being better to apprehend and learn from new information. For example, they may be more receptive to learning new skills.
Brain anatomical substrate leading to declining
This refers to biological differences in the brain structures that may increase tolerance to neuropathologies, such as neurodegenerative diseases.
The anatomical differences involved in the cognitive reserve are numerous and complex, such as differences in white and grey matter in several brain structures. Recent studies have highlighted these differences by analyzing brain structure loss in Alzheimer's Disease at a cellular level. Researchers have found that white matter volume decreases in different brain regions in a patient with mild cognitive impairment at the same rate as that which is experienced by normal aged individuals. People with higher cognitive reserve performed better and had highly efficient brain networks that seem to be more resilient in the face of changes related to ageing or disease. Their brain seems to be able to compensate more to decline than other brains.
In effect, the more cognitively complex and stimulating the environment is, the more challenges you give your brain, the greater the effects on brain function across the lifespan are going to be, and thus the lower your chances of developing any type of cognitive decline. So what can you do to stimulate your brain?
- Learn a new skill (e.g., learn how to dance, learn to play musical instruments.)
- Learn a new language
- Learn some computer skills
Keeping your mind active is not the same as keeping your mind engaged with puzzles, games, or other entertaining activities. For example, watching TV can play a negative role in cognitive reserve. What is important here is to learn something completely new.
It is equally important to note that continuing education has been demonstrated to increase brain resiliency and is associated with a positive impact in the prevention of mild cognitive impairment and Alzheimer’s-type dementia by improving cognitive function and lower dementia incidence.
The protective factor of regular physical activity
Meta-analysis of studies looking at the impact of exercising show an inverse correlation between exercise and the possibility of developing dementia. This supports the theory that cognitive decline could be prevented through exercise, only requiring individuals to follow through with the exercise regime.
Exercising is helpful for a variety of reasons, including because it does improve cardiovascular and cerebrovascular health. More specifically, although all exercises had an overall slight improvement on a measure of cognitive function such as executive function and memory, resistance training was found to be the best type of exercise for improving reasoning performance. Another meta-analysis including participants with mild cognitive impairments found that aerobic exercises improved memory and global cognitive function but had equally good effects on measures of functional independence and measures of secondary outcomes (e.g., speed/attention tests and other cognitive tests).
In general, physical activity has been actively associated with a reduced risk of developing dementia because it allows the free flow of blood and oxygen to brain tissue, allowing for optimal functioning of neurons and cell membranes. However, they are many potential mechanisms at play while exercising which could be associated with indirect effects in improving brain decline and prevent dementia. Exercising effects are seen on modifiable risk factors of dementia, such as obesity, increased insulin resistance, hypertension, hypercholesterolemia, improving glucose regulation, as well as general cardiovascular fitness. Exercising is also known for reducing cortisol, reducing vascular risk, improving cardiorespiratory fitness, and as such helping with brain decline. Physical activity can be as such, a preventative measure to brain decline.
Mechanisms associated with improved cognition and lower risk for dementia are associated with the fact that exercising increases brain concentrations levels of the Brain-Derived Neurotrophic Factor (BDNF), a protein essential to increase neurogenesis, cerebral blood flow and which protects the brain from damage by pruning neurons, in effect, remodelling and repairing neuronal fibres.
Because the lack of exercise effect is specifically true for older adults who do not exercise and have an increased likelihood to develop dementia, than those who do, it is also important to find the correct types of exercises for each generation. It is also important to make sure that your body is healthy enough to exercise first before you start a new exercise routine.
Preventing social isolation as a preventive factor
Evidence has shown that social isolation is a serious risk factor for dementia. Social isolation places a person at risk for cognitive decline. The extent and severity of the risk depend on the nature of the situation and isolation can be experienced in various ways: a person may have a lack of friends, family members, or social activities. Nonetheless, isolation is associated with poor quality of life due to an increased risk for depression, suicide, coronary heart disease, and stroke. Furthermore, people who are socially isolated are more likely to die prematurely than those who are not isolated.
If all such conditions are indeed known to impact the risk of developing dementia, social isolation however is associated with increased cognitive inactivity and the cognitive impact of limited social interaction. And indeed, studies have further shown that loneliness, the sense of being alone and isolated from others, can significantly impair cognitive performance. One study found evidence to suggest loneliness is linked to mental decline, particularly involving hippocampal volume and memory function. At least one study has also found an association between social isolation and a more rapid rate of progression from mild cognitive impairment to Alzheimer’s disease.
All these are risk factors highlights the importance of considering social engagement as a priority, as much for our mental than our emotional health. Evidence indicates that cognitive stimulation through various social activities has been shown to have effects on preventing, delaying or reducing dementia risk by increasing brain reserve. It is equally important to note that some longitudinal studies have also demonstrated that psychological factors were important when it came to social activities, showing that people who developed dementia, in the long run, had increased levels of difficulties engaging socially. So it is important to consider what may lead you to increase your social engagement. What are the things that would stimulate your mind to increase your social interactions? Here are a few suggestions:
- Make new friends with different lifestyles and interests to stimulate your brain and its social network for a long time to come.
- Visit and engage with new cultures.
- Form a fundraising group of friends to support the local library or community centre in your area (social engaging).
- Maintain a social and cognitive engagement with your current or previous workplace.
- Participate in a local charity where you can use your long acquire expertise for the work they carry.
- Find a new hobby and seek out clubs where you can mingle, such as hiking, dining, or dancing clubs.
The protective factor of maintaining a healthy diet
Nutritional deficiencies are common in individuals who have been diagnosed with dementia. The type of diet you eat (vegan/vegetarian, Mediterranean, etc.) will have a significant effect on your cognition. Studies show that those who adhere to a Mediterranean-like diet have higher rates of cognitive function and more effective brain power than those who do not keep this type of diet. Such individuals normally have a low intake of meat and dairy, with a high intake of fruit, vegetables, and fish.
Participants in such studies also had fewer vascular risk factors, reduced plasma glucose and serum insulin concentrations, insulin resistance, and markers of oxidative stress and inflammation than the control group. Other longitudinal neuropsychological tests performed at baseline and during the study termination also indicated that the evaluation of the cognitive function for the participants on a Mediterranean diet supplemented with extra virgin olive oil (1 L per week) or mixed nuts (30 g per day) and reduced dietary fat improved measures of cognitive function. Furthermore, although such diet as an intervention had limited evidence for patients who had mild cognitive impairment, none of the healthy participants had developed dementia at the end of the longitudinal study.
That condition suggests that an early diet intervention is likely to have a positive effect on later cognitive ageing and might prevent dementia.
A study has found that people who drink two cups of green tea (Camellia sinensis) per day are less likely to have cognitive impairment than those who drink three cups or less. The effect was attributed to the increased level of polyphenols and catechins flavonoids in green tea. Not only does green tea decrease the risk of cognitive impairment, but also have positive effects on the brain. More so, an assessment of a total of 21 studies, 4 of which were randomised controlled trials, have indicated that the effects of green tea or green tea extracts, l-theanine and epigallocatechin gallate - both components of green tea - had a positive effect on the general neuropsychology (e.g., increased attention) with positive effect reported in the working memory as seen in functional magnetic resonance imagery.
Omega-3 polyunsaturated fatty acids have demonstrated a positive capacity to modulate inflammatory and immune responses, as well as reducing insulin resistance, and have consequently the ability to decrease the risk of neurocognitive impairments. Specific types of Omega-3 polyunsaturated fatty acids (among 11 types), such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), when expressed in higher levels have been associated with a reduced risk for developing dementia. Such components have positive neuroprotective properties and are known to equally have anti-inflammatory, antioxidant and act against the accumulation of toxic proteins (amyloid and tau proteins).
On the other hand a diet high in saturated fat, salt and sugar can increase your risk of dementia. In another longitudinal study, healthy adults aged 60 and over were followed for four years. At the end of the study, researchers found that people who consumed more than 28 grams of fat daily had a higher risk of developing mild cognitive impairment (MCI) or dementia. Furthermore, a diet high in salt has been linked to an increased risk of cerebrovascular diseases and dementia as indeed, increase use of dietary salt promotes neurovascular and cognitive dysfunction (as well as promoting heart diseases and hypertension, which are leading causes of dementia).
There is strong correlative evidence for a correlation between diet, lifestyle factors and the onset and consolidation of dementia and Alzheimer’s disease (AD). As such, it is possible to reduce the risk of dementia and Alzheimer's or delay their onset by taking certain preventative strategies and following a healthy diet. In this regard, adopting healthy dietary patterns is a key component to avoid dementia. A healthy is characterized by a high intake of plant-based foods, probiotics, antioxidants, soybeans, nuts, and omega-3 polyunsaturated fatty acids as well as a reduction in the intake of saturated fats, animal proteins, and refined sugars.
The protective factor of maintaining a healthy weight
Maintaining a healthy diet is directly associated with avoiding obesity. Obesity is a known risk factor for diabetes, cardiovascular disease, and cancer, and thus, it has numerous effects on health. Being overweight or obese specifically increases your risk of developing dementia, more so in middle age (< 45 years old) however fit has been demonstrated that people who had followed a successful weight-loss program have decreased their risk of developing dementia. And a large scale study on people age 65 years or older has shown that maintaining a healthy body weight reduces the risk of developing Alzheimer's disease by one half when compared to being overweight or obese.
What can you do if you're overweight or obese?
- Consult a nutritionist
- Make sure you know your Body Mass Index (BMI) and develop a plan to get it below 25
- Make sure to identify the condition that led to your obesity
- Identify factors in your diet that have contributed to your obesity. Start to eat a healthy diet (low in saturated fat, low in salt and sugar) to reduce body weight
- Improve cardiorespiratory fitness by walking regularly
- Keep blood pressure under the recommended limit because when your body weight increases, your blood pressure can rise
- Slowly start to adopt a regular exercise routine
The protective factor of avoiding depression
There is a clear relationship between depression and the development of dementia. The association is even more relevant in lat-life (<65 Years old) where the diagnostic of depression can increase the odds of developing dementia by more than 50 %. This condition is equally brought by different emotional conditions, such as low mood, anxiety which affect your ability to be socially active and engage in stimulating activities, leading to isolation and further increasing the chances of developing dementia.
Furthermore, people affected by a chronic low mood and depression have been shown to have an increased amount of amyloid-beta plaques and neurofibrillary tangles leading to an increased risk of dementia. These findings suggest that depression can accelerate the process of developing dementia. Indeed, evidence suggests that depression can affect cognitive processes such as speed of processing, executive functioning, memory and visuospatial abilities.
Depression is a mental affective disorder that involves persistent sadness and loss of interest in life activities and hence, successful prevention of depression would avoid these negative outcomes.
Understanding how one can reduce the possibility of having depression necessarily requires one to understand the leading factor bringing up a depressive mood (See Risk Factor of Dementia):
- A vulnerability to mood disorders can be brought about by an inability of an individual to manage and reduce stress effectively. In this case, it is mandatory that one finds a way to manage stress in order to avoid long term consequences. Depressive feelings are often related to a decrease in the stimulation of positive emotions, while at the same time increasing negative emotions such as anger and sadness. As such, it is crucial to put emphasis on finding ways of increasing positive emotions such as doing things that you enjoy, being able to maintain an active social life and/or engaging in activities that bring you happiness.
- When an individual is unable to cope with the daily stresses of life and face a major loss in life such as the death of a loved one, it can trigger depression. In this situation, it is crucial that one should seek help from the relevant counselling services to deal with this personal loss as well as accepting that indeed their loved one has died and it is not possible to reverse or change this condition.
- Early-life adversities can hold a heavyweight in the psyche of the individual. In such a case a depressive mood is one of the most prominent symptoms brought about by early-life adversities. In this case, it is crucial to find ways that allow you to face these adversities with a greater sense of resilience and optimism. Dwelling on a negative thought pattern is an indication that depression can set in, thus it is crucial to find ways of avoiding this thought process by redirecting your attention to new things and activities that give you a sense of pleasure and happiness. Sometimes, it is useful to put into perspective our situation by trying to help people even less fortunate than us. In other times, the situation calls for a more in-depth look at your psychology, specifically when your behaviour is entangled in a harmful self-destructive lifestyle, and as such, starting Cognitive and Behavioural Therapy (CBT) is recommended.
- When medication is recommended, engaging in exercising as an adjunct to an antidepressant medication can yield higher results.
- When depression arises from a low level of social support in life, it is important to seek out support from friends and family by disclosing your feelings, asking for advice, or participating in group activities.
- Excessive alcohol intake is associated with harder behavioural control of your depressive mood, so avoiding alcohol is important.
The protective factor of good sleep habits
A good night's sleep is vital for everyone to maintain optimum health, both physically and mentally. Studies have also uncovered a link between poor sleep and the development of dementia with an increased odds for developing dementia with poor sleep. Poor sleep habits, as such, are associated with a higher risk of developing dementia. The reason is that poor sleep impairs your ability to clear the amyloid and tau proteins during the night (one of the main causes of dementia), increases inflammation and glucose metabolism (also known as blood sugar), which are all factors of brain health.
Unhealthy sleep patterns include:
- not sleeping for long enough (less than what you need per night, which depend on genetic factors)
- sleeping for too long (or above your normal average)
- having irregular sleep habits (e.g, sleep poorly or below our needs during the working week and recovering during the weekend)
Consistency is paramount to good sleep. Knowing how many hours you need to be rested, your chronotype (when your organism is prompting your sleep drive and following it), going to sleep at the same time, avoiding blue lights (laptops and mobile screens), stimulant intake and heavy activity (allowing your brain to unwind) and avoiding to eat before sleep (reducing the metabolism before sleep ) are all important aspect to get a good night sleep. If you are unsure about these, or you are having difficulty maintaining such a schedule or suffer from the effect of bad sleep, it is important to invest time to find solutions for them. Sleep is currently considered one of the most important aspects of achieving brain health in general.
The protective factor in avoiding alcohol.
Drinking in moderation has a directly known incidence of increased life span and healthy ageing. Drinking too much alcohol increases your risk of having higher blood pressure and increase the risk of stroke. It has an equal possibility to the development of dementia. The reason is simple. Alcohol use can lead to a decline in the ability of the brain to talk and recall things, affecting learning and memory capabilities. Normal alcohol enhances neuroinflammation and thereby enhance the potential for neurotoxicity. More so, unmoderated drinking (equal to or more than two drinks per day) is associated with increased alcohol-related neurotoxicity and leads to the downregulation of many neurotransmitters important to brain function. For example, frontotemporal dementia can be associated with alcohol abuse. Alcohol can contribute to cognitive impairment, especially when you combine it with diabetes. Alcohol interferes with how insulin works during digestion and absorption. When this happens, the body produces more sugar than it needs. As a result, high blood pressure and diabetes can occur. These conditions are especially true when you combine them with diabetes.
It should be noted that not all types of alcoholic drinks are good. Red wine appears to be particularly beneficial taking into account they are rich in healthy substances such as antioxidants, and as such act, when drunk in moderation, against age-related oxidative stress. Other substances including resveratrol and proanthocyanidins, which studies have demonstrated are responsible for the cardioprotection effect when drunk into moderation.
Finally, although it is known that the negative effect of alcohol is dose-related, it should be noted that not all studies have agreed on what constituted moderation and where is the threshold of the negative effects. Furthermore, different countries have different definitions of what is considered one standard drink, and what is considered a low-risk amount. Consequently, it has been difficult to assess the potential positive effect of low-intake of alcohol, such as cardiovascular effects, reducing your risk of diabetes (reducing insulin resistance) or stroke (for light drinking). Nevertheless, the alleged effects need to be weighed against risk factors, such as increased inflammatory response, oxidative stress and anatomical damage to the cardiovascular system.
The protective factor of avoiding smoking
The cause of dementia is often an alteration in the function of the brain. Thus, it can also be said that most forms of dementia have a neurobiological basis. Cigarette contains many neurotoxins that are known to be harmful to brain health greatly increasing your risk to develop dementia. Smoking increase the level of oxidative stress in the brain (e.g., causing your arteries to become narrower, among other effects) which triggers the formation of senile plaques and aggregates of hyperphosphorylated tau protein (Leading cause of dementia). Such risks are compounded with the risk resulting from cardiovascular disease (CVD) brought by smoking. Therefore, if you are trying to reduce your risk of developing dementia, stop smoking. Indeed, a relatively recent meta-analysis indicated that compared to non-smokers, smokers had twice the chance of developing dementia or vascular dementia.
We know that second-hand smoke is no less hazardous than regular smoke. Second-hand smoke can be equally hazardous to a person’s health as the smoking itself. It is known that many of the toxins present in cigarette smoke kill brain cells, and they cause oxidative stress, which leads to neuron loss (a natural process in the brain.).
What to do if you smoke? Wanting to quit is the first step. Without a strong will, it is more difficult to stop smoking. To quit smoking is to use nicotine replacement therapy (NRT) or varenicline. However, there are other ways to help you stop smoking. For example, health professionals recommend avoiding environmental triggers that may trigger a relapse such as coffee shops, pubs, and restaurants. Several pharmacotherapies for the cessation of smoking are available, such as Gamma-Amino-butyric-Acid (GABA) agonists, that have had a proven efficacy to help you smoking.
Summary
They are many lifestyle factors that are associated with risk factors that are modifiable factors that are known to potentially prevent dementia: not smoking, drinking only a moderate amount of alcohol, exercising regularly, having a balanced diet, eating fruit and vegetables daily.
Consequently, we need to be careful of our lifestyle factors. You should eat a healthy balanced diet, take care of your health, and avoid dangerous substances that are harmful to your health. These habits have shown to reduce your risk of developing cognitive impairment and dementia. It is important that you monitor yourself and measure how you are doing in these activities so that you can better decide what steps you need to take in order for them to be better each day.
A considerable amount of dementia's symptoms is now found to be manageable and while the underlying disease is still, despite much progress in the field, not yet curable, the course and progress of the disease can be modified with good dementia care and intervention.
