With around 90% of protein metabolic waste being excreted by the kidneys, some researchers have theorized that high protein diets, especially those undertaken by athletes and bodybuilders, could lead to ailments such as chronic kidney disease by putting strain on the organs. A recent systematic review, however, appears to have disproven this notion, and has even gone so far as to demonstrate a positive relationship between protein and kidney disease.
How was the study carried out?
In the mass review, scientists looked at more than 148,000 participants with 8,746 of those suffering with chronic kidney disease (CKD). High protein diets of all types, including plant-based proteins, were then correlated with the CKD cases to determine the relationship between high protein diets and CKD. In most of the cases, a high protein diet was defined as either 1.5 grams per kilogram of body weight, at least 20% of a person’s total calories, or 100+ grams daily.
What were the results?
“The inverse associations between higher level of protein intake and risk of CKD were all observed in dietary total protein,” stated the review. Data showed that a lower CKD risk was significantly associated with high protein diets, including plant or animal protein, and especially for fish and seafood intake. Indeed, all high protein diets, and especially those with plenty of seafood actually served to lower the risk of CKD rather than increase it. The long-chain omega-3 polyunsaturated fatty acids in fish, like salmon, are thought to slow the decline in kidney function, explaining why seafood came out tops in the review.
How much is too much protein?
With no study as yet showing a maximum dosage of protein, and even dosages as high as 4.4 grams per bodyweight being deemed safe, there are likely many other aspects on an individuals diet that should be addressed before curtailing our consumption of protein.