Lifestyle Intervention Study for Dementia Risk Reduction in Healthy Adults Aged Over 50 Years - The LEISURE study

Lifestyle Intervention program (LIFE) The LIFE program is a personalised multimodal lifestyle intervention designed to reduce modifiable risk factors for dementia. The LIFE program integrates exercise, diet, mindfulness, and sleep components into a comprehensive intervention specifically targeted towards metabolic, inflammatory, and neurogenic biological pathways supportive of healthy brain ageing. The LIFE program will be individually tailored to each participants’ needs across the four intervention components. Each component of the LIFE program is detailed below. Exercise program The exercise intervention will consist of a mixed-mode training program incorporating both supervised and unsupervised exercise. All sessions will be performed in a fitness setting with qualified personal trainers for participant supervision and instruction. Following baseline assessment and randomisation, participants will complete an introductory session with an Exercise Physiologist to assess baseline strength, educate participants on equipment use, safety, individualise the program as necessary and complete a supervised run-through of the program. Participants will complete three, 60-min exercise training sessions per week for 12 weeks. Participants will complete one supervised session with an exercise professional per week in a small-group setting. The other two sessions per week will be completed unsupervised, with general audio-visual guidance provided in the exercise setting. Each session will include a 10-min warm-up, followed by 4-6 individually-prescribed whole-body exercises performed at a moderate intensity in a circuit-based format with minimal rest (rating of perceived exertion, Borg Scale 10-15). Resistance weight, sets, and repetitions will be aimed at improving general functional fitness (strength, balance and function) and will be set at approximately 40-60% repetition maximum, for 1-3 sets of 8-12 repetitions per exercise. Participants will then complete 10 minutes of cardiovascular exercise at a moderate to high intensity (bike, treadmill, rowing, stepping), and a 10-min cool-down. Attendance at the fitness setting where the intervention will be delivered will be monitored for participant compliance. Intensity will be individually prescribed in the initial session and will be regularly monitored and adjusted as needed by the exercise physiologist during the supervised sessions. Modifications to exercise intensity and program difficulty will be made in a progressive manner and will take into account participant feedback, safety concerns, and recovery. The intervention will therefore be progressive, and periodised to allow for recovery, adaptation, and minimise the risk of injury. Diet program The intervention comprises a Modified Mediterranean diet (ModiMed), based on the Australian Dietary guidelines and the Dietary Guidelines for Adults in Greece. The ModiMed diet is rich in vegetables, fruit and whole grains with an emphasis on increased consumption of oily fish, olive oil, legumes and raw unsalted nuts. Moderate consumption of lean read meat and reduced fat dairy is included. The ModiMed diet comprises the following energy ratios: 39% total fat (e.g. 22% monounsaturated fat), 37% carbohydrates, 17% protein. The diet program will consist of an initial one-on-one consultation (approx. 60 minutes) with an Accredited Practising Dietitian (APD), followed by six fortnightly group sessions (approx. 90 minutes), concluding with a final one-on-one post-intervention assessment. The primary focus is on increasing diet quality while reducing intake of energy dense, nutrient poor foods. Weight loss is not an aim of the intervention; rather, the intervention is designed to increase diet quality, with a focus on foods that enhance gut health. At the first session, the dietitian will conduct a diet history (incorporating a check list of commonly-consumed foods) to assess usual dietary intake. This will be done using a seven-day food diary. Additional sessions will incorporate goal setting, label reading, motivational interviewing techniques, and mindful eating, as part of the individualised dietetic support. Participants are encouraged to set personalised goals at each session and identify barriers/motivators to change. In the group-based sessions, participants will participate in group discussions and receive dietetic and peer support focused on identifying and addressing barriers to healthy eating and increasing capacity for sustained dietary change. They will have the opportunity to ask questions of the dietitian and also to receive guidance and support regarding food shopping, as well as recipes focussed on simple, healthy, affordable, tasty meals using Mediterranean-style dietary principles. At the final session, which is once again an individual session, goals achieved are summarised, with longer term strategies for achieving sustainable change addressed. Compliance with the diet will be assessed using the Food Frequency Questionnaire (FFQ). Mindfulness program The mindfulness program will utilise a standardised mindfulness technique developed for use in longitudinal RCTs. The mindfulness training will begin by using a mindful breathing task and will then slowly be expanded to include all activities of daily living. The program will consist of eight instructor-led group training sessions of approximately 90 minutes duration. Participants will attend group sessions weekly during the first four weeks of the intervention (4 sessions) and then fortnightly thereafter on weeks six, eight, ten and 12 (4 sessions). These sessions will focus upon the delivery of the mindfulness technique and instructions to participants. Participants will also have the opportunity to discuss their experience with the program and receive personalised advice regarding their mindfulness practice, as well as engage in a group practice session during which participants will receive guided instructions to advance their practice. The home practice component will begin at 20 min/day at the outset, increasing to 30 min/day after week 2 for the remainder of the program. Participants will be required to keep a home training diary to record time spent engaged in the exercises to monitor compliance with the mindfulness component of the intervention. Sleep program The primary focus of the sleep program will be to optimise sleep quality, quantity, and daytime functioning, as measured through both objective (sleep diary and actigraphy monitoring) and subjectively (through self-report). The sleep will consist of an initial one-on-one consultation with a sleep clinician, followed by six fortnightly group sessions, concluding with a final one-on-one session. The intervention will involve sleep hygiene education designed to improve sleep quality. Participants will complete a baseline seven-day sleep diary and actigraphy monitoring. Following this there will be a group-based orientation session to provide background and necessary information regarding the program, including the research evidence for sleep therapy. This will provide a strong rationale and impetus to the participants in making the necessary commitment to sleep change. Participants will subsequently receive six fortnightly support sessions of approximately 60 minutes each over the course of the 12-week program. The final post-intervention assessment session will be once again an individual session. Sleep improvement will be determined by post-intervention actigraphy monitoring to assess sleep quality and length over seven days, and attendance at individual and group sessions will be recorded to assess participant engagement with the program. Participants will be encouraged to set personalised goals at each session and identify barriers/motivators to change. In the group-based sessions, participants will participate in group discussions and receive clinician and peer support focused on identifying and addressing barriers to healthy sleep behaviours and patters and increasing capacity for sustained change. They will have the opportunity to ask questions of the clinician and also to receive guidance and support. At the final session, which is once again an individual session, goals achieved are summarised, with longer term strategies for achieving sustainable change addressed.