L. G. Reis and colleagues (2021), writing in Metabolites, investigated the effects of low- and high-tannin fava bean (FB) diets, both fermented and unfermented, on dog health. Fava beans are increasingly used in “grain-free” formulations but raise concerns over anti-nutritional factors and possible cardiac effects.
Beagle dogs were fed one of four FB-based diets—unfermented high-tannin (UF-HT), fermented high-tannin (FM-HT), unfermented low-tannin (UF-LT), or fermented low-tannin (FM-LT)—and compared with two commercial controls: a normal-protein grain-based diet and a high-protein grain-free diet. The trial lasted 28 days and assessed glucose response, cardiovascular function, and fecal bile acid excretion.
Key findings included:
• Fermentation with Candida utilis improved glucose tolerance and raised red blood cell counts.
• Systolic blood pressure increased, but flow-mediated vasodilation decreased.
• No adverse cardiac effects were found in dogs consuming the high-protein grain-free diet containing pulses, which also included taurine supplementation.
• Dogs fed the high-protein diet showed impaired glucose tolerance compared to those on the normal-protein diet.
The results suggest that fermentation of fava beans can enhance their nutritional profile by reducing anti-nutritional compounds and improving metabolic outcomes. Importantly, no evidence of pulse-related cardiac harm was observed in this short-term study, though the authors note that longer-term effects and breed-specific vulnerabilities require further research.
Source: Reis, L. G., Morris, T., Quilliam, C., Rodrigues, L., Loewen, M., & Weber, L. (2021). The Effects of Fermentation of Low or High Tannin Fava Bean-Based Diets on Glucose Response, Cardiovascular Function, and Fecal Bile Acid Excretion during a 28-Day Feeding Period in Dogs: Comparison with Commercial Diets with Normal vs. High Protein. Journal: Metabolites, Volume 11. Publication Date: 2021-12-01. Authors: L. G. Reis, T. Morris, C. Quilliam, L. Rodrigues, M. Loewen, L. Weber.
