In a recent publication1 in The Lancet, Livingston et al. identified nine factors which contribute to the risk of dementia. These are:
• Mid-life hearing loss - responsible for 9% of the risk
• Failing to complete secondary education - 8%
• Smoking - 5%
• Failing to seek early treatment for depression - 4%
• Physical inactivity - 3%
• Social isolation - 2%
• Hypertension - 2%
• Obesity - 1%
• Diabetes - 1%
These risk factors, adding to 35%, are potentially modifiable. The other 65% is thought to be largely related to non-modifiable risks. At this stage it is relevant to highlight the limitations of the study, including the exclusion of other important potential risk factors - diet, alcohol consumption, living near major roads and lack of sleep. This means that the potentially preventable fraction of dementia might actually be underestimated in the study.
Although the link between obesity, diabetes and hypertension, and dementia can be considered to be of a logical manner, the relationship between dementia and the other risk factors may not be so obvious. Take for example the failure to complete secondary education, which is considered a major risk factor [25% of the modifiable risk factors in the above study]. Why is this so? This is thought to occur because individuals who do not continue to study/learn throughout life are less likely to build additional ‘cognitive brain reserves’. These cognitive reserves are built during one’s lifetime, strengthening the brain’s networks so it can continue to function in later life despite damage. Another risk factor is hearing loss in middle age. Researchers have concluded that denying people a cognitively rich environment leads to social exclusion and depression, which are in turn also listed as potentially modifiable risk factors for dementia.
In Malta there are an estimated 6,000 individuals with dementia. This represents 1.5% of the general population and is envisaged to increase to 10,000 individuals by 2030.2 The cost is also striking. Taking 2009 as an example [which is the latest data available], the average cost for Malta was estimated to be €80 million, which includes both informal care as well as direct medical and social care costs.3
In keeping with the above, adopting a healthy lifestyle such as avoiding smoking, treating hypertension and diabetes can all reduce the risk of dementia [as well as reduce the risk for cardiovascular disease and cancer]. Doing exercise and having a healthy weight also helps. So stop reading and go out running!