Time Restricted Eating in Survivors Trial 2.0

Overview

After chemotherapy, older breast cancer survivors experience a faster decline in brain function. This can make it harder to enjoy life, stay social, and maintain independence. Chemotherapy can lead to poorer lifestyle habits, like unhealthy eating, less exercise, high stress, and poor sleep. Chemotherapy can also affect important health markers like blood sugar and cholesterol. Over time, these changes can damage blood vessels, which might lead to heart and brain issues. The investigators do not fully understand why brain function declines faster after chemotherapy, especially in older survivors, because there are many factors involved. In this study, the investigators will look at how lifestyle habits (like diet, exercise, stress and sleep), health markers (like blood sugar and cholesterol), and blood vessel health (like how well blood flows and how stiff the blood vessels are) affect brain function in older breast cancer survivors. The investigators will include 152 females aged 60-85 years, who finished chemotherapy for early-stage breast cancer at least 1 year ago. The investigators will use special tests to check different parts of brain function, like language, memory, and attention, as well as brain blood vessel health. This will help to understand which factors might speed up or slow down memory and thinking problems. Since many Canadian breast cancer survivors experience faster decline in brain function after chemotherapy, this study aims to find out what might make it worse. The results could help to create better and more personalized treatment plans for older breast cancer survivors that protect brain health and reduce problems with brain function in the future.

This study will be a two-centre (University of Toronto and University of Alberta), two-arm, parallel-group, randomized controlled trial in older (60+ years) breast cancer survivors. Participants will be randomly allocated to one of two groups for 16-weeks: 1) time restricted eating group + protein counselling and healthy eating education (intervention group) or 2) healthy eating education (comparison group). To standardize the potential participant bias toward healthy lifestyle changes and pre-existing physical activity tracking devices (i.e., Fitbits are common in this demographic), all participants will receive Canada's Food Guide, the Canadian 24-h movement guidelines, and a Garmin smartwatch at baseline. To enhance recruitment and retention, and in consideration of ethics of denying care to patients with elevated CVD risk, study staff will provide both groups with standardized healthy eating education following material from Canada's Food Guide 'Resources for Health Professionals' which aligns with dietary patterns that improve cardiovascular health. The investigators will standardize the type and frequency of intervention support across both groups but with differences in content. Support will consist of an initial call and check-in calls at weeks 1, 3, 6, 12 and daily text messages to act as a reminder, self-monitoring tool, and collect adherence. After the 16-week intervention, no further formal study support will be provided for participants. Participants will be informed they can continue to follow the interventions to the extent they choose for the next 6 months and that the investigators will contact them for one final assessment around that time. In-person study visits will include a \~4.5-h comprehensive assessment at baseline and again at 16 weeks, and one abbreviated \~2-h assessment at 40 weeks as a 24-week follow-up.