Figure 1 Schematic representation of the multiple factors influencing the trajectory of mental capital across the life course. Adapted from 19 and 20.
AGING, MENTAL CAPITAL, AND WELL-BEING
As populations age, it is increasingly important to understand the effects of global aging on the mental capital and well-being of older people. This has been the focus of a major Foresight project within the United Kingdom, under the auspices of the Chief Scientist and the Government Office for Science. The Foresight report “Mental Capital through Life” integrates an extensive review of the science.19 Like the Marabou meeting, for which the present work was prepared, it reflects a growing focus on how best to improve the trajectory of mental capital throughout life. An individual is born with an uneducated, unformed brain that has to develop and then sustain its mental capital until, as late as possible, it falls prey to intrinsic aging and the possible impact of neurodegenerative diseases (see Figure 1). The big challenge is to elucidate what determines this trajectory of mental functioning; the goal is to keep the trajectory as high as possible for as long as possible.20 Given new insights into the plasticity and malleability of the global aging process, new opportunities need to be considered to delay the onset of age-related deterioration in the functions of the brain and to maintain mental functioning.21
Research into the mechanisms underlying aging of the brain needs to take careful account of new discoveries concerning the mechanisms of intrinsic global aging. Aging results not from any direct genetic programming but from the gradual accumulation of damage. The longevity and health trajectory of an individual is influenced by a combination of the following factors: 1) genetic factors conferring the degree of maintenance and repair of cellular systems; 2) environmental factors, including lifestyle and nutrition, which act both on the exposure to damage and the capability of repair systems; and 3) the play of chance at the level of how damage affects molecules and cells in the brain and other organs of the body. This tripartite underpinning of health across the life course is consistent with growing evidence for the malleability of aging. It offers scope for novel interventions to improve the trajectory of brain health.
19. Government Office for Science. Foresight Mental Capital and Wellbeing Project. Available at: http://www.bis.gov.uk/foresight/our-work/projects/current-projects/mental-capital-and-wellbeing. Accessed 25 October 2010.
20. Kirkwood T, Bond J, May C, McKeith I, Teh M. Mental capital through life: future challenges. London: Government Office for Science; 2008.
21. Kirkwood TB. Gerontology: healthy old age. Nature. 2008;455:739–740.
Adapted from: Global Ageing and the Brain