From the Guidelines
Protein powder supplementation does not typically harm kidney function in healthy individuals with normal renal function, but it is crucial to consume it in moderation and as part of a balanced diet. For most healthy adults, consuming moderate amounts of protein powder (20-40g per serving) as part of a balanced diet that includes up to 1.6-2.2g of protein per kg of body weight daily is considered safe for the kidneys 1. However, individuals with pre-existing kidney disease, reduced kidney function, or a history of kidney stones should exercise caution and consult with a healthcare provider before using protein supplements. The concern stems from the kidneys' role in filtering and excreting nitrogen waste products from protein metabolism, which increases with higher protein intake.
Some key points to consider:
- 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 and therefore should be avoided 1.
- Reducing the amount of dietary protein below the recommended daily allowance of 0.8 g/kg/day is not recommended because it does not alter blood glucose levels, cardiovascular risk measures, or the course of GFR decline 1.
- It's essential to stay well-hydrated when consuming protein supplements and to obtain protein from varied sources rather than relying exclusively on supplements.
- If you choose to use protein powder, select high-quality products from reputable manufacturers and incorporate them as part of an overall balanced nutritional approach rather than as a replacement for whole food protein sources.
In terms of specific guidelines, the most recent study 1 recommends that individuals with non-dialysis-dependent CKD should aim for a dietary protein intake of 0.8 g/kg body weight per day. This level of protein intake has been shown to slow GFR decline and have a greater effect over time compared to higher levels of dietary protein intake.
Overall, while protein powder supplementation is generally considered safe for healthy individuals, it's crucial to prioritize a balanced diet and consult with a healthcare provider if you have any pre-existing kidney issues or concerns.
From the Research
Protein Powder and Kidney Function
- The relationship between protein powder supplementation and kidney function is complex and has been studied in various contexts.
- A study published in 2020 2 suggests that high-protein diets, which may include protein powder supplementation, can cause intraglomerular hypertension, leading to kidney hyperfiltration, glomerular injury, and proteinuria.
- However, another study from 2023 3 found that plant-based protein consumption may have beneficial effects on kidney function and mineral bone disorder outcomes in adults with stage 3-5 chronic kidney disease.
Dietary Protein Sources and Kidney Function
- Research has shown that different dietary protein sources can have varying effects on kidney function.
- A 2017 study 4 found that red and processed meat consumption was associated with increased risk of chronic kidney disease, while higher dietary intake of nuts, legumes, and low-fat dairy products was associated with lower risk.
- A review of the literature published in 2007 5 suggested that animal protein can cause dynamic effects on renal function, whereas plant-based proteins such as egg white, dairy, and soy do not.
High-Protein Diets and Kidney Function
- High-protein diets have been shown to accelerate renal deterioration in individuals with chronic kidney disease.
- A study from 2000 6 found that high protein intake (up to 2.8 g/kg body weight) did not impair renal function in well-trained athletes, but the long-term effects of high protein intake on kidney function are still poorly understood.
- Another study published in 2020 2 emphasized the need for caution when adopting high-protein diets for weight reduction or glycemic control, particularly in individuals at high risk for kidney disease.