Dementia is an umbrella terms that describes conditions that cause neurocognitive disorders. These are progressive conditions that worsen and lead to multiple impairments in memory and thinking, ultimately leading to severe disability. The main cause of dementia in Australia is Alzheimer’s disease, followed by vascular disease. Currently about 250,000 Australians have dementia. In the past we thought that there was nothing that could be done to influence whether or not a person developed dementia. However, over the past 10 years our knowledge of the risk factors for dementia has grown significantly.
Scientists have conducted very large cohorts of adults as they age – some studies spanning 10, 20 or 30 years. Factors measured at the commencement of these studies have been linked to the eventual outcome of a dementia diagnosis. These studies do not establish causality – they are observational studies. Further research is often conducted using animal models to evaluate the underlying mechanisms by which risk factors operate. So how can you reduce your risk?
Diet and weight: A healthy diet, low in saturated fats, with the recommended amount of vegetables and three or more fish meals per week. Avoid over eating and a high sugar diet. In mid-life (40-60s) years, being overweight increases the risk of dementia in late-life. But once you are over 60, the association between weight and dementia is diminished.
Physical activity: A sedentary lifestyle is associated with increased risk of dementia. So follow the recommended guidelines for remaining physically activity – aerobic and strength training activities have been shown to improve cognition.
Manage chronic conditions: Conditions such as high blood pressure, diabetes and heart disease increase the risk of dementia or other conditions that cause dementia – so optimal management through medication and lifestyle is advised.
Look after your brain: Unfortunately, head injuries increase the risk of dementia in late life. So avoiding head injury through out your life, including through sports, is another way you can minimize your risk of dementia.
Smoking: Don’t! Current smokers had an 80% increased risk of dementia.
Social and mental wellbeing: Seeing friends, and attending social activities four or more times per week is protective against dementia in long term studies – we don’t yet understand the mechanism for this finding and we don’t yet know how social networking via the internet helps but it seems that the general principle of maintaining your social life and enjoying social activities is good for our brain. On the other hand, clinically significant depression increases the risk of dementia, so if you have depression it is important to seek treatment.
Cognitive engagement: It seems that the adage ‘use it or lose it’ is true. Neuroimaging studies have now shown that there is brain growth after people undertake activities that require new learning – but cognitive engagement can involve things such as visiting museums, attending plays and concerts, playing board games, reading, discussing ideas, and undertaking further study. Keep challenging yourself to learn new things and think.
Keeping socially active, managing weight and regularly exercising are some of the ways we can reduce our risk of dementia.