Although age is the biggest risk factor for dementia, dementia is not an inevitable part of getting older. Genetics only cause dementia in a small proportion of cases. In most people, lifestyle factors play a role in determining how likely they are to develop the condition. The risk of dementia is lower in people who:
- have higher levels of education
- work in more “mentally demanding” occupations
- have cognitive stimulation (reading, doing puzzles, learning a second language)
- are socially active (e.g. socialising, volunteering)
Risk factors for dementia
Around 40% of dementia cases worldwide might be attributable to 12 potentially modifiable risk factors (Figure 1, Source: Livingston, G. et al. Dementia prevention, intervention, and care: 2020 report of the Lancet Commission). Each item in the list has the percentage reduction in dementia prevalence if this risk factor is eliminated:
- early life: less education (under 20) 7%
mid life
- hearing loss 8%
- traumatic brain injury 3%
- hypertension 2%
- alcohol >21 units per week 1%
- obesity 1%
later life
- smoking 5%
- depression 4%
- social isolation 4%
- physical inactivity 2%
- air pollution 2%
- diabetes 1%
Some of these risks can be reduced even in older age, for example stopping smoking, or using hearing aids to address hearing loss.
The National Institute for Health and Care Excellence (NICE) recommends reducing the risk of or delaying the onset of disability, dementia and frailty by helping people to:
- stop smoking (prevalence of smoking in Suffolk is similar to England, Figure 2)
- be more active (percentage of physically inactive adults in Suffolk is similar to England, Figure 2)
- reduce their alcohol consumption
- improve their diet
- lose weight if necessary and maintain a healthy weight
NHS health checks, for adults aged 40 – 74, measure cholesterol, blood glucose and blood pressure, so are a useful opportunity to identify potential risks as well as advise patients on healthier lifestyle. In the period 2016/17 – 2020/21, 44.1% of Suffolk’s eligible population received an NHS health check, significantly better than England as a whole (33.4%).
In summary (see also Figure 2, Source: Public Health England Fingertips Dementia Profile), and compared to England, Suffolk has:
- Similar percentage of 16-17 year olds not in education, employment or training. A lower percentage of the population educated to NVQ4 and above (34.6% compared to England’s 42.8%)
- Higher rates of hypertension (and increasing).
- Similar rates of self-reported hearing loss for Ipswich and East Suffolk and West Suffolk CCGs, but higher for Norfolk and Waveney CCG.
- Similar smoking prevalence.
- Similar percentage of adults (18 and over) classified as overweight or obese according to survey data, although the percentage of adults recorded on GP registers as overweight or obese is higher than England (11.4% compared to 10.5%).
- Higher recorded prevalence of depression (and increasing).
- A lower percentage of physically inactive adults (20.2% compared to 22.9%).
- Prevalence of diabetes similar to England (increasing).
- Pre-pandemic, there was a similar percentage of adult social care users (in the 18 years and over age group and in the aged 65 and over age group) who had as much social contact as they would like. During the pandemic (14/10/2020 to 22/2/2021) Suffolk had a similar percentage of people who “often or always” felt lonely. Note that these measures are not ideal for measuring infrequent social contact; the Office for National Statistics emphasise “it is important not to confuse loneliness and social isolation. They are different concepts requiring different approaches to measurement”, mainly because one is subjective (loneliness), while the amount of social contact can be objectively measured.
- A lower percentage of adults in Suffolk abstain from alcohol (12.5% compared to 16.2%), although the percentage of adults binge drinking is also lower, and the percentage of adults drinking over 24 units of alcohol per week is similar to England (all measures 2015-2018 data).
- Headway (the brain injury association) has calculated the number of admissions in England for non-superficial head injuries have increased by 30% since the start of the century (to 2016/17). Headway’s calculated rates per 100,000 population for the CCGs covering Suffolk: 156 (Great Yarmouth and Waveney CCG), 186 (Ipswich and East Suffolk, 249 (West Suffolk). These compare to a rate of 240 for England.
- 5.3% mortality is attributable to particulate air pollution in the population aged 30 and over (England 5.1%).
Medical conditions
Pre-existing medical conditions that can increase the risk of dementia include:
- Parkinson’s disease,
- Stroke (Suffolk has higher prevalence than England as a whole, Figure 2)
- type 2 diabetes,
- high blood pressure or hypertension (Suffolk has higher prevalence than England as a whole, Figure 2)
Higher recorded prevalence (e.g. hypertension) may be due to increased diagnosis, enabling better management:
- 2019/20 data show management of hypertension (measured as the proportion of people with hypertension with “satisfactory blood pressure control”) varies by Suffolk CCG: Norfolk and Waveney has a significantly lower percentage than England, West Suffolk similar, and Ipswich and East Suffolk higher (Figure 3, Source: Public Health England, Fingertips National General Practice Profiles).
- In 2018/19, West Suffolk CCG and Ipswich and East Suffolk CCG had a higher (better) percentage of people with type 2 diabetes who met treatment targets for glucose control, blood pressure and cholesterol, but Great Yarmouth and Waveney CCG was significantly worse than England (Figure 4, Source: Public Health England, Fingertips Diabetes Profile).
Inequalities
There is greater prevalence of dementia among black and South Asian ethnic groups.
In the UK, 62% of people with dementia are female and 38% are male. This is likely to be because women live longer than men and age is the biggest known risk factor for the condition (although it is not an inevitable part of ageing). Dementia is the leading cause of death among women in the UK. Women are more likely to care for someone with dementia, and those who act as dementia carers feel less supported than their male counterparts. Many carers feel isolated and depressed, which are risk factors for dementia.