Study on blueberries, protein and exercise for improving frailty and cardiovascular disease (STRONG): protocol for a parallel-group randomised controlled superiority trial in older Nova Scotians.

INTRODUCTION

As frailty and cardiovascular disease are closely linked, lifestyle interventions to reduce frailty could improve cardiovascular health in at-risk individuals. Previous clinical trials have shown that exercise reduces frailty, both individually and in combination with dietary protein. Blueberries can improve vascular health and protect against cellular senescence. The objective of the study on blueberries, protein and exercise for improving frailty and cardiovascular disease (STRONG) is to determine whether a year-long treatment including blueberries, protein and exercise will reduce frailty and improve cardiovascular health in older adults of both sexes.

METHODS AND ANALYSIS: STRONG is a pragmatic randomised controlled trial 1 year in length with an additional year of follow-up. We will recruit 240 adults aged ≥65 years (120 females and 120 males) in Nova Scotia, Canada. Participants will be randomly assigned to the STRONG intervention group (1 cup of blueberries/day, 30 g of protein powder/day and three 60-min multimodal exercise sessions with an exercise physiologist/week) or the control group (usual care). Measured outcomes will include changes in frailty (eg, frailty scores, balance, falls, changes in life-space, social engagement), cardiovascular disease risk factors (eg, blood pressure, lipid profile, Framingham risk score), cardiovascular health (eg, 6-min walk test, cardiac function measures), inflammatory markers, physical fitness, diet quality and health-related quality of life. All measures will be collected at baseline and 12 months, with many also repeated at the 3-, 6-, 9- and 24-month time points.

ETHICS AND DISSEMINATION: This study has received approval from the Nova Scotia Health Research Ethics Board (ROMEO #1031656) and is being conducted according to Consolidated Standards of Reporting Trials (CONSORT) and Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidelines. The findings will be disseminated through peer-reviewed publications, academic and community presentations, lay materials on our research team websites and social media and summaries/briefings to stakeholders that will be directed toward registered dietitians, exercise physiologists and clinicians.

TRIAL REGISTRATION NUMBER: NCT06693271.