ISSUE #1 — Many physicians believe that high protein diets cause kidney dysfunction
RESPONSE #1 — This is FALSE according to everything science now knows to be true. This presumption states that if you take a healthy person and put them on a high protein diet, the protein will somehow negatively influence the kidney, damaging it and causing renal disease. To this end, there is absolutely no data in healthy adults suggesting that a high protein intake causes the onset of renal (kidney) dysfunction. There arenʼt even any correlational studies showing this effect in healthy people.
Any studies that show a correlation between renal (kidney) dysfunction and protein intake are in those with some type of diagnosed, pre-existing renal (kidney) disease like diabetic nephropathy, glomerular lesions, etc. Even research into protein restriction for renal patients can be controversial. (Shils, Modern Nutr in Health & Dis, 1999).
Besides, youʼll likely recognize a serious pre-existing kidney condition; the signs and symptoms will clue you in long before you happen upon it with a routine blood test (especially if there's a noted family history of diabetes mellitus and hypertension).
Since an exhaustive search of the published literature will likely not yield a single study showing that the amount of protein in the diet causes, or is correlated with, the onset of renal dysfunction in otherwise healthy individuals, the fact that this notion prevails is puzzling to say the least!
But even if a doctor were to find an obscure reference that might suggest a relationship between a high-protein diet and kidney disease, there are numerous studies showing otherwise. Here are a few of them:
a) Ann Intern Med 2003 Mar 18;138(6):460-7
The impact of protein intake on renal function decline in women with normal renal function or mild renal insufficiency.
Knight EL, Stampfer MJ, Hankinson SE, Spiegelman D, Curhan GC.
b) Int J Sport Nutr Exerc Metab 2000 Mar;10(1):28-38
Do regular high protein diets have potential health risks on kidney function in athletes?
Poortmans JR, Dellalieux O.
c) Int J Obes Relat Metab Disord 1999 Nov;23(11):1170-7
Changes in renal function during weight loss induced by high vs low-protein low-fat diets in overweight subjects.
Skov AR, Toubro S, Bulow J, Krabbe K, Parving HH, Astrup A.
d) Eur J Clin Nutr 1996 Nov;50(11):734-40
Effect of chronic dietary protein intake on the renal function in healthy subjects.
Brandle E, Sieberth HG, Hautmann RE.
e) Am J Kidney Dis 2003 Mar;41(3):580-7
Association of dietary protein intake and microalbuminuria in healthy adults: Third National Health and Nutrition Examination Survey. "Dietary protein intake was not associated with microalbuminuria in normotensive or nondiabetic persons."
If youʼre interested, these studies can be accessed at
www.pubmed.com.
