Having a particular form of a gene that predisposes people to dementia also tends to confer a slightly faster cognitive decline than those that do not have this form of the gene. Overall, genes account for 24% of the change in intelligence across the life course; although we can't do anything about our genes, this research suggests that environmental factors are therefore likely to be responsible for 76%. If three-quarters of lifetime change in intelligence are down to our environments, finding things that we can modify in our interactions with the environment is likely to have a marked impact on our mental and physical ageing. Some examples of lifestyle behaviours that we have found to influence our cognitive skills in old age are:
[This was published in Nature in January 2012. This journal only publishes the most original and novel research at the forefront of international excellence – the sort of science that changes the world. Genetic data from the LBC1936 was the major study in the research.
Smoking affects cognitive ageing. In the LBC1936, those people still smoking at age 70 performed more poorly on tests of general cognitive ability and processing speed than ex-smokers and those who had never smoked. These relationships held after taking into account their cognitive ability in early life, health factors and lung function. Not only that, but the team found that, in the LBC1936, it was people with lower childhood cognitive ability who were more likely to take up smoking in the first place, and were less likely to give it up. Ex-smokers showed no decrement in thinking skills compared to never smokers suggesting that quitting smoking at any stage in adulthood may be beneficial to cognitive health in later years.
This was published in Journal of Psychosomatic Research (2012).
Advice: Giving up smoking, even in one's later years, may be one of the most important things you could do to prevent age-related cognitive decline.
Although several studies have reported beneficial effects of moderate alcohol consumption on cognitive abilities in later life, the LBC team found that this relationship was partly a result of those people with a higher cognitive ability in childhood choosing to drink moderately in adulthood, and having a preference for wine consumption. Beer consumption was linked with poorer thinking skills in both childhood and later life. Overall, we found that higher alcohol consumption (roughly equivalent to 1-2 glasses of wine per day, but not to excess!) was linked with better memory and verbal ability, although these effects were small.
This was published in Neuropsychology (2011).
Advice: Drinking moderately, especially wine, may have a small protective effect on some cognitive abilities as we age.
The role of diet in cognitive ageing is still unclear. In the LBC1936 to date, we have looked at the effect that antioxidants, B-vitamins and flavonoids, obtained from the diet, have on cognitive abilities in old age. Our data suggest that the observed association between the healthy dietary factors above and better cognitive abilities in old age (as suggested by many previous studies) can be explained by an influence of prior IQ on diet in later life rather than an influence of diet on cognition. However, as the study is on-going, we intend to look more closely in the future at the role of one's diet overall, as well as other specific dietary factors, on brain ageing over time.
These studies were published in the European Journal of Clinical Nutrition (2011) and the British Journal of Nutrition (2011).
Avoiding illnesses including cardiovascular disease can keep the brain thinking better. One thing that might improve cardiovascular health is keeping active. Physical activity protects our thinking and our brains in later life. The benefits of physical activity to physical health are increasingly understood. Research from our team indicates that physical activity appears to protect your brain from several aspects of ageing. In contrast, people who engaged in activities commonly thought to keep the mind active (social and intellectual leisure activities) did not necessarily have better measures of brain structure than people who did fewer of these activities.
These were published in Psychology and Aging and in Neurology in 2012
Advice: Increasing your amount of physical activity, even in later years, may have a protective effect on your brain's health, but check with your GP before taking up an exercise programme if you have not been active for a long time or have a medical condition. Even though keeping mentally active might not be as beneficial to your brain's physical health, it can still be of important benefit to your quality of life!
WHITE MATTER MATTERS
White matter integrity and thinking skills are linked. The project team found that older people with more intact white matter can process information faster and that this makes them generally smarter. Protection of white matter is now a clear target for preserving good cognitive function in later life.
This was published in Molecular Psychiatry (2012).
Brain size and white matter lesions are linked. Previous studies had found that the brain gets smaller with age (atrophy) and also that patches (lesions) appear in the brains white matter. The project team found that people whose brains had greater atrophy had more white matter lesions. This finding is important in that it shows that these apparently differing age-related structural changes may have similar biological mechanisms, a finding which may help inform future management strategies.
This is currently in press in European Radiology.
Our research team also contributes to other resources on ageing well. For example, Dr Robin Morton recently wrote a piece for the Edinburgh Council magazine "Get Up & Go" which can be viewed here . There is also a video about the magazine (and their annual awards), which you can see at: http://youtu.be/d-arUjvQuNg which happens to feature a member of the Lothian Birth Cohort!
Prof Ian Deary, Prof John Starr and other leading experts in the field have also contributed to an authoritative guides to ageing better and understanding ageing, produced by Age UK:
Both guides can be ordered for free by calling Age UK on 0800 169 65 65.