Ageing and dementia: a global priority
18 December 2024
All over the world today, people are living longer. This trend contributes to the growth of both the size and the proportion of elderly people in the population. In fact, by 2050, the world population of people aged 60 and over will reach 2.1 billion.
Therefore, the health of people in old age is now a priority for health systems, given the rapid ageing of the population and the increasing burden of chronic diseases.
Among these, dementia represents one of the most urgent and complex challenges – with an estimated 57 million sufferers worldwide in 2019 and expected to increase to 153 million by 2050.
When we talk about dementia, we refer to the progressive decline in cognitive abilities that impairs a person’s autonomy by interfering with the normal ageing process. Dementia encompasses a range of disorders, including Alzheimer’s disease and vascular dementia and has an increasing impact not only on those affected and their families, but also on health and social systems.
According to the 2024 Lancet standing Commission report, almost half of the world’s dementia cases could be prevented by addressing 14 modifiable risk factors.
Modifiable risk factors
As mentioned above, it is clear that many forms of dementia are not an inevitable fate of ageing, and intervening early in certain aspects of our lifestyle can make a significant difference.
Scientists have identified 14 risk factors, partly related to behavioral factors, which if corrected in time, can improve the quality of life of people over 65. These include:
- Physical inactivity. Physical activity changes throughout life and decreases when a person becomes ill and varies between cultures, socioeconomic status and gender. Exploring the link between physical activity and dementia, researchers have found that increased physical activity is associated with a reduced risk of dementia for all its causes.
- Obesity. In particular, one study revealed that a larger waist circumference compared to a smaller one is associated with a higher risk of cognitive impairment and dementia, and this risk was higher in people over 65 years of age compared to other ages.
- Diabetes. Studies have shown that type 2 diabetes is classified as a risk factor in middle age associated with dementia. However, the onset of the disease late in life has negative effects on cognitive health and dementia risk.
- Smoking. This risk factor appears to be indirectly associated with dementia: in fact, it is smoking-related diseases, such as cancer and cardiovascular disease, that may affect the development of dementia.
- Excessive alcohol consumption. In fact, it has been associated with an increased risk of dementia from all causes.
- Hypertension. With regard to this risk factor, the evidence is conflicting. It turns out that high blood pressure in middle age is associated with a high risk of dementia, but with advancing years, blood pressure tends to decrease.
- Social isolation. People with little social contact tend to have a higher risk of developing dementia than people with frequent social contact.
- Depression. In fact, depression can be a symptom of evolving dementia, a reaction or a cause of cognitive impairment.
Furthermore, studies have shown that there are also risk factors unrelated to one’s lifestyle that contribute directly or indirectly to an increased risk of dementia. For example, having suffered a traumatic brain injury, hearing loss, low level of education, air pollution, untreated vision loss and high LDL cholesterol levels.
Integrated strategies for healthy ageing
Promoting healthy longevity and preventing dementia requires an integrated approach combining individual actions and ambitious public policies.
Several population-level interventions could substantially reduce the prevalence of dementia through the implementation of public policies.
Investing in education and prevention starting in early childhood; facilitating access to preventive medical care, such as screening for cholesterol, diabetes and vision loss; and reducing exposure to air pollution through policies that improve air quality are actions that could also have significant benefits on dementia risk in the long term.
Other policies should focus on planning favourable urban environments that support people to adopt healthy lifestyles. For example, increasing or upgrading green spaces and infrastructure for physical activity, especially in disadvantaged communities.
Finally, encouraging a healthy diet and meeting recommended levels of physical activity not only helps reduce risk factors, but also allows people to age healthily and live longer.
These interventions not only improve people’s health and quality of life but could significantly reduce long-term healthcare costs and ensure a more sustainable future for all.
Sources:
Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission
WHO, Ageing and Health
