Dementia is a condition characterised by a set of signs and symptoms, including impaired memory, behavioural changes, and loss of cognitive and social functioning brought about by progressive neurological disorders (Barber, 2020). There are over 200 subtypes of dementia, but the most common are Alzheimer's, vascular, Lewy body, mixed dementia (often a combination of Alzheimer's and vascular) and frontotemporal dementias (Sandilyan and Dening, 2019) (Table 1). There are estimated to be 944 000 people living with dementia in the UK and such modelling indicates this will increase to 2 million by 2051 (Wittenberg et al, 2019). While dementia is associated with advanced age, an estimated 7.5% or 70 800 people are living with young onset dementia, where symptoms occur under the age of 65 years (Carter et al, 2022). Dementia and Alzheimer's disease are progressive and life-limiting conditions, and are the leading cause of death for females in England and Wales, accounting for 40 250 deaths (14.0% of all female deaths) (Office for National Statistics (ONS), 2021).
Table 1. Common types of dementia
| Type | Description | Symptoms |
|---|---|---|
| Alzheimer's disease |
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| Vascular dementia |
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| Lewy body dementia |
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| Frontotemporal dementia |
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| Mixed dementia |
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The national campaign to raise public awareness of dementia through the first National Dementia Strategy (Department of Health (DH), 2009) and later, the Prime Ministers' challenge (DH, 2015), were perceived as successful. However, one of the negative consequences of the heightened population awareness of dementia has also been in raising societal fear. Dementia is now the most feared condition above cancer (Tang et al, 2017). One of the other recommendations of the national dementia strategy (DH, 2009) was in support of the early recognition and diagnosis of dementia (Fox et al, 2013). In particular, the delayed or late diagnosis of dementia was proposed as having an insidious and devastating impact on the outcomes for patients and their families by delaying or denying them access to essential post-diagnostic support and information (Bamford et al, 2021).
Risk factors for developing dementia
While there is yet to be a cure for dementia, we know more about its causes and some of the life course factors that may increase a person's risk of developing the condition later in life. The risks can be divided into: non-modifiable and modifiable factors. Non-modifiable risk factors are those that we can do nothing about to change or ameliorate, whereas modifiable risk factors can be impacted on over time through various actions to reduce or eliminate the risk.
Modifiable risk factors
The Lancet Commission has produced two reports on the risk factors for dementia with a third in its planning stage. In both of these reports (Livingston 2017; 2020) the interdisciplinary, international group of experts presented, debated and agreed on the best available evidence and performed systematic reviews and meta-analysis of included studies. The first report detailed nine potentially modifiable risk factors for dementia (Livingston et al, 2017). In 2020, Livingston and colleagues added three further modifiable risk factors, bringing the new total to 12 (Livingston et al, 2020). These include lower education levels, hypertension, hearing impairment, smoking, obesity, depression, physical inactivity, diabetes, low social contact (Livingston et al, 2017), excessive alcohol consumption, traumatic brain injury and air pollution (Livingston et al, 2020). Livingston and colleagues (2020) stated that these risk factors should be considered over a life-course model of dementia prevention (Figure 1). They went on to suggest that these 12 modifiable risk factors account for around 40% of worldwide dementias, which could theoretically be prevented or delayed through a healthy lifestyle. Tackling modifiable risk factors of dementia involves both health promotion and health management in primary care. As part of their everyday practice, nurses in primary care should aim to promote and support healthier lifestyles in patients; such health promotion can be key to the prevention of some forms of dementia.
Education
Many risk factors cluster around inequalities, which occur particularly in Black, Asian and minority ethnic groups, and in vulnerable populations. Therefore, nurses who work in deprived rural and urban areas need to factor this in when taking on health promotion-related activities. Access to relevant health-related information early in the life course can be significant, with higher levels of education in childhood associated with a 7% reduction in the risk of developing dementia later in life. This is felt to be one of the most potent benefits to be derived from improving the educational levels and achievements in early life. Education should also be promoted throughout a person's life course. However, in lower middle-income communities, standards and access to secondary education is likely to be lower and contributes to an increased risk of dementia (Livingston et al, 2020).
Hypertension
Persistent midlife hypertension is associated with an increased risk of dementia in later life. Achieving a systolic blood pressure of 130 mmHG or less is key from around the age of 40 years to help reduce this risk (National Institute for Health and Care Excellence, 2022). Thus, proactive blood pressure monitoring through regular scheduled health checks and education about healthier eating, weight loss in overweight persons, exercise and lifestyle can be promoted from a very early age and then revisited at various junctures throughout a person's life course.
Midlife hearing impairment
Interest in age-related hearing loss (ARHL) has been growing, not only from the perspective of being one of the most common health conditions affecting older adults, but also from the perspective of its relation to cognition (Uchida et al, 2019). Results from a number of studies have demonstrated a significant link between ARHL and cognitive decline. However, untreated midlife hearing loss can increase the risk of dementia in later life as a result of cognitive overload (exceeding cognitive capacity leading to an inability to process further information, thereby feeling overwhelmed and confused) and reduced cognitive stimulation as hearing loss progresses (Ray et al, 2018; Uchida et al, 2019). Hearing tests and screening should be offered by all occupations where noise-related work exceeds upper exposure action values, but also awareness of the effects of hearing loss can be promoted in many interactions with people who attend for a range of other conditions. Simple signage in waiting rooms and the promotion of the free hearing tests that are available on the NHS website (NHS England, 2020,) as well as a GP referral to an audiologist may prove beneficial.
Smoking
In 1998, the UK government announced the introduction of smoking cessation services throughout the NHS (DH, 1998). In many areas, such services did not exist; yet, now they are widespread. Smokers face a 50–80% increased risk of dementia due to the toxic effects of the smoke on the lungs and vascular system. However, evidence suggests that smoking cessation at any age can help reduce the risk of dementia in later life by 5% (Winblad et al, 2016). Primary care professionals should assess nicotine dependency at every reasonable opportunity and when a treatment plan is agreed upon, the pharmacotherapy should be individualised and monitored, ensuring it is part of the smoking cessation intervention (Primary Care Respiratory Society, 2023).
Depression
Depression is a common mental disorder. Globally, it is estimated that 5% of adults suffer from it, with depression being a leading cause of disability (WHO, 2021). It is generally characterised by persistent sadness and a lack of interest or pleasure in previously rewarding or enjoyable activities, as well as a disturbed sleep pattern and appetite. Tiredness and poor concentration are common. The effects of depression can be long-lasting or recurrent and can dramatically affect a person's ability to function. In later life, depression is associated with a twofold increase in dementia incidence of Alzheimer's disease; however, research continues to determine if this is a true risk factor or a prodrome to dementia (Joe et al, 2019). The Patient Health Questionnaire—PHQ-2 and PHQ-9—have been shown to be effective, valid and reliable for detecting depression in primary care. The PHQ-2 is a simple two-item measure to use and indicates that a score of ≥3 may then lead to undertaking the PHQ-9 or refer to specialist mental health services for a clinical assessment for a major depressive disorder (Levis et al, 2020).
Physical activity
Promoting physical activity is an important part of care in community nursing and has been investigated in many studies (van der Wardt et al, 2021). Many nurses and primary healthcare staff promote exercise in people they come into contact with during the course of their work through interventions such as counselling. However, this has been shown to have a limited effect on peoples' behaviour and might not, on its own, be enough to change behaviours pertaining to physical activity (van der Wardt et al, 2021). Social prescribing is now available in primary care settings, whereby exercise interventions can be offered to promote sustainability in physical activities (Yaman and Atay, 2018), but many schemes are for people with existing conditions, such as mental health problems and frailty, and not accessible to all. Despite these barriers, physical activity is the largest influencer on modifiable risk reduction of dementia but requires consistent engagement throughout the life course. Activity of a low physical intensity can reduce the risk of dementia by 40% and even reverse causation of dementia (Norton et al, 2014; Winblad et al, 2016). It may be that primary care services engage with other local stakeholders and providers to promote exercise activities, such as partnerships with, for example, local gyms and voluntary groups.
Diabetes
In a systematic review of studies following large groups over many years, Cheng and colleagues (2012) found that adults with type 2 diabetes have a higher risk of developing Alzheimer's. According to one study's results, type 1 diabetics were 93% more likely to develop dementia (Lacy et al, 2018). Having diabetes increases the risk of vascular, Alzheimer's or mixed dementia by 50% in later life, with the risk increasing with the duration of diagnosis, poor control and severity (Winblad et al, 2016). Diabetes education and information should be available for both people diagnosed with diabetes but also available for other users of healthcare services. This places nurses in a good position to provide further information, especially for those at greater risk. This includes individuals from Black and minority ethnic groups and those with a learning disability (Care Quality Commission, 2016).
Obesity/diet
Obesity prevalence appears to be increasing in all countries within the UK, apart from Northern Ireland. Scotland has the highest prevalence of obesity in the UK (UK Parliament, 2023). Obesity is a chronic condition that requires long-term management and is associated with unprecedented stigma in different settings, including during interactions with the health-care system (Albury et al, 2020). Primary care nurses can play a pivotal role in the prevention and management of obesity in both children and adults. Albury and colleagues (2020) developed a consensus statement to inform how the subject of obesity could be discussed in healthcare conversations, to ensure there was opportunity during each interaction with clients to provide advise on weight and, if necessary, discuss prevention. Obesity and diabetes are inextricably linked and a persistently high Body Mass Index (>30) results in an increased risk of dementia in later life (Albanese et al, 2017). Diets high in plants, nuts and olive oil, such as that seen in a Mediterranean diet, which is also low in saturated lipids and red meat, can reduce the risk of cognitive decline (Livingston et al, 2017). These include:
- Leafy green vegetables, at least six servings/week
- Other vegetables, at least one serving/day
- Berries, at least two servings/week
- Whole grains, at least three servings/day
- Fish, one serving/week
- Poultry, two servings/week
- Beans, three servings/week
- Nuts, five servings/week
- Wine, one glass/day (Alcohol to be taken in moderation; how the body handles alcohol can change with age)
- Olive oil (Liu et al, 2021).
Social isolation
There is also a relationship between social isolation and brain function. Social isolation has been shown to lead to and accelerate the risk and progression of symptoms of depression and dementia in later life. Social networks, loneliness, anxiety and depression in older people are all interrelated (Domènech-Abella et al, 2019), so there is increasing recognition that social health can be protective against disease, including age-related cognitive decline and dementia. However, the relationship of social networks is often based on reciprocity between any social network member; this adds to problems for people with dementia as they lose the ability to connect and communicate. Therefore, they are at an increased risk of social loss as they deteriorate, which in turn worsens cognitive decline (Sachdev, 2022). Those living with multi-morbidity and frailty are also susceptible as their opportunities to socialise increasingly reduces (Holwerda et al, 2014; Curelaru et al, 2021). Community nurses need to be aware of local social prescribing arrangements as this is a way of addressing a patient's ‘non-medical’ needs, for example, loneliness, which can affect a person's health and well-being and, in the long term, lead to the risk of dementia. This may involve signposting them to relevant local services, such as groups, organisations, charities, activities, events or by referring them to a social prescribing service (Tierney et al, 2020).
High alcohol consumption
NHS England has advised on alcohol consumption, recommending that ≤14 units of alcohol can be consumed per week and spread across 3 days or more (NHS England, 2023a). That is, 14 units of alcohol equates to six medium (175ml) glasses of wine, or six pints of 4% beer. As part of their ‘better health—let's do it’ approach, they have advised that there is no completely safe level of drinking, but sticking within these guidelines lowers your risk of harming your health (NHS England, 2023a). Alcohol is associated with health risks when abused at levels beyond those recommended above and over a long-term period; health risks, amongst others, include cognitive impairment and dementia. Chronic drinking of more than 21 units per week, is considered harmful, leading to a 17% increased risk of dementia in later life (Sabia et al, 2018; Wiegmann et al, 2020). This type of ‘at risk drinker’ is someone who does not meet clinical criteria for alcohol use disorder. Alcohol use disorder is a psychiatric illness defined as alcohol use causing clinically significant impairment or distress, characterised by impaired control over drinking and ongoing drinking despite harmful consequences (American Psychiatric Association, 2023). Community nurses can offer advice and support for at-risk patients during annual health checks or other condition-specific appointments and can use basic first line counselling to promote healthier drinking habits (Spithoff and Kahan, 2015). Suggested strategies to reduce alcohol intake include:
- Setting a goal for reduced drinking
- Setting an amount for each dr inking day (for example, no more than three drinks on Thursday, Friday, and Saturday)
- Not drinking alone
- Allocating and stick to nondrinking days
- Recording drinks in a calendar, logbook, or smartphone application
- Arriving at drinking events and leaving at predetermined times (for example, only stay 3 hours at a pub or party)
- Eating before and while drinking
- Starting drinking later in the evening or night
- Switching to a less preferred alcoholic drink
- Pacing your drinking (for example, no more than one drink per hour)
- Sipping drinks slowly
- Alternating alcoholic drinks with non-alcoholic drinks
- Drinking plenty of water while drinking alcohol
- Waiting 20 minutes between the decision to dr ink and actually having the dr ink (Spithoff and Kahan, 2015).
Traumatic brain injury (TBI)
TBI is a key contributory risk factor in dementia, especially in those with sporting careers where they experience frequent head injuries, such as in rugby and football (Livingston et al, 2020). During interventions and support, community nurses can offer advice to those involved in the sport, their parents/partners, to avoid head-to-head, arm-to-head or foot-to-head collisions with other participants.
They should be adviced to wear the right protective equipment for their sport, such as helmets, padding, shin guards, and eye and mouth guards. Traumatic brain injury does not just arise from contact sport; therefore, community nurses need to be aware of other possible risk factors (Centers for Disease Control and Prevention, 2021).
Air pollution
Air pollutants are emitted from a range of both man-made and natural sources. Many everyday activities such as transport, industrial processes, farming, energy generation and domestic heating can have a detrimental effect on air quality. Due to the growing global warming concerns air pollutants, such as methane and black carbon, are powerful short-lived climate pollutants (SLCPs) that contribute to climate change and ill health (WHO, 2023). Almost all of the global population (99%) is exposed to air pollution levels that exceed the safe WHO guideline level for fine particulate matter (PM 2.5µg/m3) (WHO, 2023). Exposure to environmental air pollutants such as ambient toxic substances and pollutants of particulate matter and carbon monoxide increase the risk of cognitive impairment and dementia (Livingston et al, 2020). This modifiable risk factor is probably more impactful on poorer populations that live in urban areas with social housing and high traffic volume. This arguably makes it less modifiable from an individual perspective and requires national and the local government's attention. However, community nurses have an important part to play in helping people understand the effects of air pollution on their health and in offering advice on managing their conditions, as well as actions they can take to reduce their day-to-day and lifetime exposure to air pollution. For example, people with asthma or other respiratory conditions should be advised not to undertake vigorous exercise when outdoor air pollution levels are high (Public Health England (PHE), 2018).
Non-modifiable risk factors
Non-modifiable risk factors of dementia cannot be changed. However, a greater awareness can lead to early detection and diagnosis. This enables the person to have timely access to post-diagnostic support and service and to live as well as possible with their dementia.
Age
Age is the most consistent and significant of the non-modifiable risk factors, with the incidence and prevalence rates of dementia doubling every 5 years from the age of 65–85 years. In addition, more women are affected by Alzheimer's disease than men (Vergallo et al, 2020).
Genetic factors
At least 20 genes are known to be associated with an increased risk of developing Alzheimer's disease. The gene Apolipoprotein E (APOE) type E4 is associated with the greatest increased risk of developing late-onset Alzheimer's disease (Hye and Velayudhan, 2020). Alzheimer's disease is characterised by abnormal accumulation of the Aβ protein, which is a normal product derived from the amyloid precursor protein (APP) (Chen et al, 2017). The prevalence of dementia in people with a learning disability is 2–3 times greater than in the general population, particularly for people with Down's syndrome (PHE, 2018).
Ethnicity
There is some evidence to suggest an increased prevalence of dementia in Afro-Caribbean and South Asian populations when compared to the White population of the UK (Turner et al, 2012). However, diagnosis rates may differ amongst ethnic groups due to differences in seeking and receiving a diagnosis of dementia (Pham et al, 2018). What is known is that Black and Asian ethnic group are more likely to experience cardiometabolic risk factors such as diabetes and obesity which increase their risk of dementia (All-Party Parliamentary Group on Dementia, 2013).
Mild cognitive impairment (MCI)
A third of all people who have MCI go on to develop a dementia within 3 years (Barrett and Burns, 2014). Thus, it is important to monitor people with MCI to enable early access to treatment and support or treat another primary cause.
Parkinson's disease
Dementia occurs more commonly in Parkinson's disease than in the age-matched general population, with a prevalence of between 20%–45%, depending on the precise definition of dementia that is adopted (McKeith and Burn, 2000; Schott, 2020). Community nurses, if aware of this risk in people who have a diagnosis of Parkinson's disease, can be vigilant for early signs of cognitive impairment that may indicate a possible dementia.
Conclusion
Overall, the 12 modifiable r isk factors account for around 40% of worldwide dementias, which could theoretically be prevented or delayed (Livingston et al, 2020). The potential for prevention is high and community nurses should consider the opportunities that may arise in their everyday practice to promote brain health and dementia prevention throughout a person's life course. Livingston and colleagues (2020) have called for policy recognition such as prioritising childhood education for all, which would enable a fundamental knowledge of the implications for a healthy lifestyle. However, healthcare professionals can also play a significant role in both health education, health promotion and in being vigilant when some of the risk factors come in to play in patients' lives. Similarly, the NHS Health Check programme (NHS England, 2023b), alongside other routine checks, support people with long-term health conditions to be monitored and managed effectively.
Key points
- There are 12 recognised risk factors for dementia, nine of which can be modified over a person's life course to reduce or prevent their risk of developing dementia in later life
- Primary care and practice nurses are well placed to support people with health education and promotion activities
- It is never too early and never too late in the life course for dementia prevention..
CPD reflective questions
- What advice would you give to one of your patients on alcohol consumption levels that may positively impact on their risk of developing dementia in later life?
- In your day to day role, think about how you might advise your patients about the importance of remaining socially connected in later life
- Reflect on a recent patient you have cared for; think about any risk factors of dementia that they may be exposed to. What actions could they take to minimise these?