The differential effect of animal versus vegetable dietary protein on the clinical manifestations of diabetic kidney disease in humans

Patients with diabetes are at a high risk for kidney disease and cardiovascular disease (CVD). Inadequate glycemic control or conventional cardiovascular risk factors do not fully explain these vascular complications. Insulin resistance has been established as a powerful and independent risk factor for both CVD and diabetic kidney disease (DKD). The source of dietary protein (animal versus vegetable) largely defines the degree of insulin sensitivity. Animal protein intake activates glucagon secretion and magnifies insulin resistance while vegetable food enhances insulin sensitivity. Reducing animal meat while augmenting vegetable protein has demonstrated definite advantages regarding insulin sensitivity.A comprehensive literature search was conducted on the PubMed database up to December 2021 on the differential effect of animal versus vegetable protein on DKD. Articles written in English concerning human subjects were included.Animal protein is strongly associated with clinical features of DKD (glomerular hyperfiltration, albuminuria and kidney function decline) and CVD. Conversely, plant-sourced protein has a strong beneficial effect on both DKD and CVD. Plant-based diets have demonstrated to be nutritionally safe in subjects from the general population, patients with diabetes, and patients with kidney disease. Available evidence suggests that the dietary potassium load due to plant-sourced food does not usually induce hyperkalemia, although future research is required to establish the effect of meat (and subsequent insulin resistance) and vegetable food on kalemia.Nutritional advice to patients with diabetes should consider the strikingly different effect of animal versus vegetable protein on insulin resistance and its clinical consequences.