Large epidemiological studies have shown that low-fat dairy intake reduces the risk of developing gout. It was hypothesised that factors within dairy fractions inhibit the inflammatory response to monosodium urate monohydrate (MSU) crystals.
Dairy fractions were tested in MSU crystal-stimulated THP-1 cell assays. Fractions with inhibitory effects were then tested in the murine urate peritonitis model.
Two dairy fractions were found to have consistent inhibitory effects. Glycomacropeptide (GMP) and G600 milk fat extract both inhibited interleukin-1beta (IL1beta) gene and protein expression in the THP-1 cell assay. Conversely, standard milk fat increased IL8 protein expression in the THP-1 cell assay. Oral administration of GMP and G600 milk fat extract inhibited cellular influx in the urate peritonitis model.
Both protein and lipid fractions within dairy products are capable of modulating the inflammatory response to MSU crystals.