The effect of dietary interventions on brain-derived neurotrophic factor (BDNF) levels in adults: a systematic review of clinical trials

BACKGROUND: Brain-derived neurotrophic factor (BDNF) is crucial for brain development, neuronal function, and metabolism. This systematic review aims to comprehensively examine the impact of various diets on BDNF levels, addressing gaps in understanding diet's influence on BDNF's role in neuroprotection and metabolism. METHOD: This systematic review was conducted in accordance with PRISMA 2020 guidelines. An extensive search was conducted in PubMed, Web of Science, and Scopus up to April 2024, using terms related to diet and BDNF. Relevant clinical trials involving adults were included. Data extraction covered study design, participant details, and outcomes, with quality assessed using the Cochrane method. Clarifications from authors were sought as needed to ensure comprehensive analysis. RESULTS: This review examined 7633 articles to assess the impact of various diets on BDNF levels, narrowing down to 13 studies. The study found varying effects: intermittent fasting and ketogenic diets generally increased BDNF, while other diets showed minimal or no impact. The review highlights diverse outcomes and the need for further research on dietary effects on BDNF. CONCLUSION: The review found that fasting and calorie restriction diets generally increase BDNF levels, while other dietary interventions showed inconsistent effects. Further research is needed to better understand these dietary impacts on BDNF and to develop optimized strategies for enhancing cognitive health and managing obesity.