A Mediterranean Diet and Walking Intervention to Reduce Cognitive Decline and Dementia Risk in Independently Living Older Australians: The MedWalk Randomized Controlled Trial Experimental Protocol, Including COVID-19 Related Modifications and Baseline Characteristics.

BACKGROUND: Several clinical trials have examined diet and physical activity lifestyle changes as mitigation strategies for risk factors linked to cognitive decline and dementias such as Alzheimer's disease. However, the ability to modify these behaviors longer term, to impact cognitive health has remained elusive. OBJECTIVE: The MedWalk trial's primary aim is to investigate whether longer-term adherence to a Mediterranean-style diet and regular walking, delivered through motivational interviewing and cognitive-behavioral therapy (MI-CBT), can reduce age-associated cognitive decline and other dementia risk factors in older, independently living individuals without cognitive impairment. METHODS: MedWalk, a one-year cluster-randomized controlled trial across two Australian states, recruited 60-90-year-old people from independent living retirement villages and the wider community. Participants were assigned to either the MedWalk intervention or a control group (maintaining their usual diet and physical activity). The primary outcome is 12-month change in visual memory and learning assessed from errors on the Paired Associates Learning Task of the Cambridge Neuropsychological Test Automated Battery. Secondary outcomes include cognition, mood, cardiovascular function, biomarkers related to nutrient status and cognitive decline, MI-CBT effectiveness, Mediterranean diet adherence, physical activity, quality of life, cost-effectiveness, and health economic evaluation.Progress and Discussion:Although COVID-19 impacts over two years necessitated a reduced timeline and sample size, MedWalk retains sufficient power to address its aims and hypotheses. Baseline testing has been completed with 157 participants, who will be followed over 12 months. If successful, MedWalk will inform interventions that could substantially reduce dementia incidence and ameliorate cognitive decline in the community. TRIAL REGISTRATION: Registered on the Australia New Zealand Clinical Trials Registry ANZCTR 12620000978965 (https://www.anzctr.org.au).

Liver and inflammatory biomarker relationships to depression symptoms in healthy older adults.

INTRODUCTION: Early identification and management of physical and mental illness is vital to maintain quality of life as we age. Markers of peripheral inflammation and liver function show elevations with aging, and are also associated with depression symptoms, suggesting a similar pattern in both aging and clinical groups. METHODS: The current study examined the relationship between such markers and measures of depression/negative mood in 284 healthy older adults using data from the Australian Research Council Longevity Intervention (ARCLI). Baseline data in adults aged 60-75 included mood symptoms via Profile of Mood States and Beck Depression Inventory II, and peripheral inflammatory (TNF-α, IL-6, hs-CRP) and liver markers (GGT, ALT, AST, AST:ALT ratio) derived from blood samples. RESULTS: The inflammation and liver enzyme relationship significantly predicted mood symptoms scores. Results showed that a significant relationship between C-reactive protein (CRP) and negative mood scores on Total Mood Disturbance and four of the six subscales (all p < .01) was dependent upon higher levels of gamma-glutamyl transferase (GGT). DISCUSSION: Higher levels of normal-range liver metabolic and peripheral inflammatory markers are observed with negative mood in a healthy older sample experiencing the biological impact of aging, but in the absence of clinical depression symptoms, suggesting a possible role of oxidative stress or other biological mechanisms occurring with aging in depression etiology. Lifestyle interventions are discussed.