Current and emerging nutrition interventions in cardiac rehabilitation: a narrative review

Cardiac rehabilitation (CR), a multi-modal program centered around supervised exercise, is considered the standard of care for secondary cardiovascular disease (CVD) prevention. The primary goals of CR are managing CVD risk factors and improving patient quality of life through exercise, diet, and risk factor management. While exercise is considered the cornerstone program component, concurrent consumption of diets that provide adequate fruits, vegetables, whole grains, healthy fats, and lean protein, with a reduced intake of ultra-processed foods, saturated fats, added sugar, and sodium, are a key recommendation for secondary CVD risk reduction and risk factor management. Considerable evidence supports the role of Mediterranean Diet (MedDiet), Dietary Approaches to Stop Hypertension (DASH), and plant-based diets for primary and secondary CVD prevention. Yet, these dietary patterns have limited patient adherence and are subject to limited availability of registered dietitian in CR programs. To-date, research on the efficacy of dietary patterns within CR settings (i.e., concurrent to exercise and other risk factor management strategies) is limited, with only 11 randomized controlled trials conducted between 2000 and 2020. This review provides an overview of the current heart-healthy dietary recommendations and their efficacy for secondary CVD prevention. Novel dietary patterns with promising cardioprotective effects, such as time-restricted eating (TRE), are described as possible alternative dietary patterns. Limitations inherent to both current and novel dietary patterns are outlined. Future research directions aimed at enhancing the utility of dietary strategies to enhance the benefits of CR are suggested.