Effects of regular whey protein consumption on rat thyroid functions

Background/aim: We aimed to investigate whether there was a significant difference in TSH, T3, T4 values and histopathologically evaluated thyroid tissues between rats that received ısole hydrolyzed whey protein (IHWP) at different doses regularly and rats fed with only standard feed. Material & methods: Total 24 rats were randomly divided into three groups with 8 rats in each group. First group were fed with standard feed for 12 weeks. Second group were given standard feed + daily 0.3 g/kg IHWP and rats in the third group standard feed + 0.5 g/kg IHWP for 12 weeks. Blood samples were collected from all rats before and after IHWP administration. All rats were then sacrificed, and thyroid tissues were histopathologically examined. Results: Interfollicular connective tissue areas and TSH (0.35–4.90 μIU/L) were higher in the control group compared to 3 cc IHWP and 5 cc IHWP groups, while thyroid hormone T4 (0.7–1.48 ng/dL), and thyroid hormone synthesis parameters including intrafollicular colloid amount, follicular diameter, and epithelial height were significantly higher in 3 cc and 5 cc IHWP groups compared to the control. Conclusion: We think that regular daily use of IHWP may increase the synthesis of thyroid hormone due to its high amino acid content.