This research is based on the LIILAC TRIAL; Lifestyle Intervention Independent Living Aged Care.
The world’s population is moving into an over 65+ age group. (Mathers, 2013). This 65+ age group is the fastest growing segment with an expected 1.2 billion people worldwide being aged 65 years or over by 2025 (Forette, 2012). In Australia it is estimated that 25% of the population will be 65+ by the year 2030.
The cost of supporting an ageing demographic, particularly with their associated medical requirements, is becoming an ever increasing burden that is predicted to rise in the foreseeable future. The progressive decline in an individual’s cognitive ability as they age, particularly with respect to the ever increasing incidence of Alzheimer’s disease (AD) and other cognitive complications, is, in many respects, one of the foundations of great concern to all nations. It has been estimated that in 2015, 47 million people around the world were living with various forms of dementia, and this is expected to increase to 85 million by 2030 and potentially 135 million by 2050 (Prince et al., 2016).
There is currently 184,000 Australians living in retirement village accommodation which is predicted to increase to approximately 382,000 by 2025 (Thornton, G et al 2014) The aged care sector in Australia is experiencing an increasing demand for permanent residential aged care, with greater than 50% of permanent residential aged care residents living with dementia (Care, 2017)
Brain ageing occurs over a lifetime and is the progressive and gradual accumulation of potential detrimental changes in structure and function. Furthermore, specific brain structures are the targets of later-life neurodegenerative disorders such as Alzheimer’s disease. Cognitive ageing is demonstrated by minor changes in some mental functions such as vocabulary, some numerical skills, and general knowledge, however, other mental capabilities decline from middle age onwards, or even earlier.
As there is currently no available medical intervention available to treat cognitive decline, early intervention through the use of modifiable risk factors is imperative in middle age to prevent the onset of cognitive decline and progression of cognitive decline into mild cognitive impairment and AD.
Previous research has focused on how interventions, such as improving nutritional status and modifying risk factors such as obesity, sedentary lifestyle, hypertension, depression, cardiovascular disease, potentially arterial stiffness, oxidative stress and hyperlipidaemia may be modified by diet (Parrott and Greenwood, 2007a; Mathers, 2013; Dauncey, 2014; Kiefte-De Jong et al., 2014; Vandewoude et al., 2016), and also by physical activity such as exercise or a combination of exercise and or diet (Komulainen et al., 2008; Deary et al., 2009; Komulainen et al., 2010; Rolland et al., 2010; May, 2011; Tarumi et al., 2011; Gorelick, 2018). The impact of how diet and exercise may modify age associated cognitive function was the focus of this thesis.