Does excessive protein intake cause renal damage?

From the Guidelines

Excessive protein intake can cause renal damage, particularly in individuals with pre-existing kidney disease or reduced kidney function, and should be limited to 0.8 g/kg body weight per day to slow GFR decline. According to the most recent guidelines from the Diabetes Care journal 1, higher levels of dietary protein intake (>20% of daily calories from protein or >1.3 g/kg/day) have been associated with increased albuminuria, more rapid kidney function loss, and CVD mortality. Key points to consider include:

• Dietary protein intake should be individualized based on kidney function and overall health status
• For people with stages 3–5 non–dialysis-dependent CKD, dietary protein intake should be 0.8 g/kg body weight per day
• Reducing dietary protein below the recommended daily allowance of 0.8 g/kg/day is not recommended, as it does not alter blood glucose levels, cardiovascular risk measures, or the course of GFR decline 1
• Low-protein eating patterns should only be followed alongside guidance from a healthcare professional experienced in managing nutrition for people with CKD
• Other factors, such as dietary sodium and potassium intake, should be individualized based on comorbid conditions, medication use, blood pressure, and laboratory data 1

From the Research

Excessive Protein Intake and Renal Damage

• Excessive protein intake has been associated with potential renal damage, including intraglomerular hypertension, kidney hyperfiltration, glomerular injury, and proteinuria 2.
• High dietary protein intake may lead to de novo chronic kidney disease (CKD) and worsen renal function in individuals with impaired kidney function 2, 3.
• The quality of dietary protein may also play a role in kidney health, with animal protein being associated with an increased risk of end-stage kidney disease (ESKD) compared to plant-based protein sources 2.

Studies on High-Protein Diets and Renal Function

• A 2011 study found that prolonged intake of high amounts of protein has been associated with potential dangers, such as bone mineral loss and kidney damage, particularly in individuals with existing kidney dysfunction 4.
• A 2005 study reviewed the available evidence and found no significant evidence to support the relationship between high protein intake and renal damage in healthy individuals 5.
• A 2016 study recommended that long-term consumption of protein at 2 g per kg body weight per day is safe for healthy adults, but chronic high protein intake (>2 g per kg body weight per day) may result in digestive, renal, and vascular abnormalities and should be avoided 6.
• A 2017 study found that the protein source may be important, with daily red meat consumption potentially increasing CKD risk, whereas white meat and dairy proteins appear to have no such effect, and fruit and vegetable proteins may be renal protective 3.