Investigation of imidazole dipeptide content in complete and balanced pet foods for cats with a focus on obesity

Abstract

Obesity in cats has been associated with various diseases, making its prevention and management a critical concern. Carnosine and anserine, both imidazole dipeptides (IDPs) with antioxidant properties, are abundant in meat and fish. Previous studies have demonstrated that dietary carnosine supplementation exerts anti-obesity effects in cats. In this study, we measured the IDP content in 63 complete and balanced pet foods for adult cats (18 wet foods, 36 dry foods, and 9 obesity-management dry foods). The results showed a tendency toward lower carnosine, anserine, and total IDP content in dry and obesity-management dry foods compared with wet foods. A moderate positive association between total IDP content and protein content suggests that, considering major protein sources in cat food are meat and fish, the quantity of protein may be influential in IDP. In contrast, the carnosine-to-anserine ratio—expected to vary with ingredient composition—did not differ significantly among products. Because anserine concentrations exceeded those of carnosine in more than 60％ of the foods analyzed, further studies are needed to determine whether anserine also confers anti-obesity effects in cats.