Higher protein nudged kidney markers in older women, but 1.6 and 2.2 g looked alike
Women aged 40 to 77 who trained for 12 weeks improved their blood fats at every protein dose tested. Kidney-related markers moved more at the higher intakes than at 0.8 g per kg, yet 1.6 and 2.2 were nearly indistinguishable from each other, and the researchers are explicit that none of the changes establishes organ injury.
For you: If you already eat around 1.6 g of protein per kg, this trial offers no sign that pushing to 2.2 buys anything different, and no proof that either dose harms healthy kidneys.
What it shows: Treat this as informative rather than a safety verdict: it is one 12-week trial in 83 middle-aged to older women, analysed after the fact for these blood markers. Diets were not fully matched on calories and food composition, so the protein dose alone cannot take the credit or the blame.RCT · Eur J Nutr