The Benefits of L-Carnitine in Enhancing Fish Health, Metabolic Regulation, and Stress Reduction: A Review

Aquaculture presents a sustainable alternative to traditional capture fisheries, offering livelihoods and a valuable protein source while alleviating pressure on natural ecosystems. However, environmental stressors often impede the success of aquaculture, posing risks to aquatic life. Functional feed additives are a promising solution to combat stress in fish culture. These additives are integrated into feed formulations to meet animals’ nutritional requirements and enhance growth, health, and stress resistance. Among these additives, L-carnitine has emerged as a promising candidate in aquaculture. By boosting mitochondrial fatty acid β-oxidation and regulating energy metabolism, L-carnitine can help alleviate stress induced by water temperature fluctuations, enhance immunity and growth, shield cells from ammonia toxicity, and eliminate harmful substances from mitochondria. While numerous studies have explored the benefits of L-carnitine supplementation in aquaculture, few studies, according to our knowledge, have reported its specific role in stress mitigation in fish. This review seeks to consolidate existing research and underscore the potential of L-carnitine in high-fat diets, growth promotion, and stress reduction. In conclusion, further exploration of L-carnitine’s mechanisms in reducing fish stress is essential, as it shows promise as a valuable additive for aquafeed formulations.