Dietary Acid Load is determined by the balance of acid-inducing food, such as meats, eggs, and cheeses, offset by base-inducing (“alkaline”) foods, such as fruits and vegetables.
Protein Source: An Acid Test for Kidney Function
Chronic kidney disease is a major public health problem affecting about one in eight Americans, increasing the risks of disease and death even among those with only mild decreases in kidney function. So, low cost, low risk preventive strategies that anyone can do are needed to address the epidemic of kidney disease.
Diet plays a role in kidney function decline. Specifically, diets higher in animal protein, animal fat, and cholesterol may be associated with protein leakage in the urine (a sign of kidney damage), and generally, diets higher in fruits, vegetables, and whole grains but lower in meat and sweets may be protective against kidney function decline.
In comparison to the diets eaten by our ancestors, not only are we eating more saturated fat, sugar, and salt, we now eat an acid-producing diet, as opposed to a base-producing or alkaline diet. Ancestral human diets were largely plant-based, and, as such, produced more base than acid.
Dietary acid load (DAL) is determined by the balance of acid-inducing food, which is rich in animal proteins (such as meats, eggs, and cheeses) offset by base-inducing foods, such as fruits and vegetables. And, in this national survey of 12,000 American adults, dietary acid load was associated with kidney damage among U.S. adults.
Acid-inducing diets are believed to impact the kidneys via tubular toxicity, damage to the tiny delicate urine-making tubes in the kidneys via increased ammonia production. See, ammonia is a base; so, the kidneys create ammonia to buffer the acid from the food we eat. This is beneficial in the short term to get rid of the acid; however, in the long term, all that extra ammonia in our kidneys day in and day out can exert toxic effects.
Our kidney function tends to decline progressively after our 30’s, and by our 80’s, our kidney capacity may be down to half. Perhaps, this so-called age-related decline in kidney function is a result of damage induced by a lifetime of ammonia overproduction. That’s just one theory, though. The acidic pH may increase the production of free radicals and damage the kidneys that way or add to scarring.
Not only is protein derived from plant foods accompanied by antioxidants that can fight the free radicals, plant protein is less acid forming in the first place, because it tends to have less sulfur–containing amino acids. One of the reasons plant foods tend to be less acid-forming than animal foods is because acid is produced by the sulfur in the protein, and there’s less in plant proteins.
So, the more important determinant of the effect of dietary protein on kidney disease progression is the quality of the ingested protein (in other words, whether it induces acid production like most animal protein, or base production like most fruit and vegetables), rather than the quantity of protein ingested.
Since American diets are largely acid-producing, because they are deficient in fruits and vegetables and contain large amounts of animal products, changing from a standard American diet to a vegan diet may improve acidosis in patients with chronic kidney disease. Under normal circumstances, a vegetarian diet is alkalinizing, whereas a non-vegetarian diet leads to an acid load. This was true even of vegetarians that consumed processed meat replacements like veggie burgers.
Plant-based diets have been prescribed for decades for those with chronic kidney failure. No animal fat, no cholesterol, less acid load, and helps lower blood pressure. And, indeed, if you compare the kidney function of vegans to vegetarians to omnivores, the most plant-based diet was most associated with improved parameters for the prevention of kidney decline.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.
Please consider volunteering to help out on the site.
- A Chang, L Van Horn, D R Jacobs Jr, K Liu, P Muntner, B Newsome, D A Shoham, R Durazo-Arvizu, K Bibbins-Domingo, J Reis, H Kramer. Lifestyle-related factors, obesity, and incident microalbuminuria: the CARDIA (Coronary Artery Risk Development in Young Adults) study. Am J Kidney Dis. 2013 Aug;62(2):267-75.
- T Banerjee, D C Crews, D E Wesson, A Tilea, R Saran, N Rios Burrows, D E Williams, N R Powe; Centers for Disease Control and Prevention Chronic Kidney Disease Surveillance Team. Dietary acid load and chronic kidney disease among adults in the United States. BMC Nephrol. 2014 Aug 24;15:137.
- P Chauveau, C Combe, D Fouque, M Aparicio. Vegetarianism: advantages and drawbacks in patients with chronic kidney diseases. J Ren Nutr. 2013 Nov;23(6):399-405. J Ren Nutr. 2013 Nov;23(6):399-405.
- J Lin, T T Fung, F B Hu FB, G C Curhan. Association of dietary patterns with albuminuria and kidney function decline in older white women: a subgroup analysis from the Nurses' Health Study. Am J Kidney Dis. 2011 Feb;57(2):245-54.
- E van den Berg, F A Hospers, G Navis, M F Engberink, E J Brink, J M Geleijnse, M A van Baak, R O Gans, S J Bakker. Dietary acid load and rapid progression to end-stage renal disease of diabetic nephropathy in Westernized South Asian people. J Nephrol. 2011 Jan-Feb;24(1):11-7.
- N Goraya, J Simoni, C H Jo, D E Wesson. A comparison of treating metabolic acidosis in CKD stage 4 hypertensive kidney disease with fruits and vegetables or sodium bicarbonate. Clin J Am Soc Nephrol. 2013 Mar;8(3):371-81.
- J Lin, F B Hu FB, G C Curhan. Associations of diet with albuminuria and kidney function decline. Clin J Am Soc Nephrol. 2010 May;5(5):836-43.
- W Chen, M K Abramowitz. Metabolic acidosis and the progression of chronic kidney disease. BMC Nephrol. 2014 Apr 3;15:55.
- J J Scialla, L J Appel, B C Astor, E R Miller 3rd, S Beddhu, M Woodward, R S Parekh, C A Anderson. Estimated net endogenous acid production and serum bicarbonate in African Americans with chronic kidney disease. Clin J Am Soc Nephrol. 2011 Jul;6(7):1526-32.
- M J Wiseman, R Hunt, A Goodwin, J L Gross, H Keen, G C Viberti. Dietary composition and renal function in healthy subjects. Nephron. 1987;46(1):37-42.
- N Goraya, D E Wesson. Is dietary Acid a modifiable risk factor for nephropathy progression? Am J Nephrol. 2014;39(2):142-4.
- G Barsotti, E Morelli, A Cupisti, M Meola, L Dani, S Giovannetti. A low-nitrogen low-phosphorus Vegan diet for patients with chronic renal failure. Nephron. 1996;74(2):390-4.
- A Sebastian, L A Frassetto, D E Sellmeyer, R L Merriam, R C Morris Jr. Estimation of the net acid load of the diet of ancestral preagricultural Homo sapiens and their hominid ancestors. Am J Clin Nutr. 2002 Dec;76(6):1308-16.
- P Deriemaeker, D Aerenhouts, M Hebbelinck, P Clarys. Nutrient based estimation of acid-base balance in vegetarians and non-vegetarians. Plant Foods Hum Nutr. 2010 Mar;65(1):77-82.
- E Kanda, M Ai, R Kuriyama, M Yoshida, T Shiigai. Dietary acid intake and kidney disease progression in the elderly. Am J Nephrol. 2014;39(2):145-52.
- J J Scialla, L J Appel, B C Astor, E R Miller 3rd, S Beddhu, M Woodward, R S Parekh, C A Anderson; African American Study of Kidney Disease and Hypertension Study Group. Net endogenous acid production is associated with a faster decline in GFR in African Americans. Kidney Int. 2012 Jul;82(1):106-12.
- J Uribarri, M S Oh. The key to halting progression of CKD might be in the produce market, not in the pharmacy. Kidney Int. 2012 Jan;81(1):7-9.
- B M Brenner, T W Meyer, T H Hostetter. Dietary protein intake and the progressive nature of kidney disease: the role of hemodynamically mediated glomerular injury in the pathogenesis of progressive glomerular sclerosis in aging, renal ablation, and intrinsic renal disease. N Engl J Med. 1982 Sep 9;307(11):652-9.
- J Coresh, E Selvin, L A Stevens, J Manzi, J W Kusek, P Eggers, F Van Lente, A S Levey. Prevalence of chronic kidney disease in the United States. JAMA. 2007 Nov 7;298(17):2038-47.
Images thanks to Hey Paul Studios via Flickr, Pongsak Kaewmanaprasert, Acha Yhamruksa, Sommai Larkjit, Anna Liebiedieva, and Rob Marmion via 123rf, Bambo, OpenPics, PublicDomainPictures, and Lebensmittelfotos via Pixabay, Gajda-13 Fir0002, and Snufkin7 via Wikimedia Commons.
Chronic kidney disease is a major public health problem affecting about one in eight Americans, increasing the risks of disease and death even among those with only mild decreases in kidney function. So, low cost, low risk preventive strategies that anyone can do are needed to address the epidemic of kidney disease.
Diet plays a role in kidney function decline. Specifically, diets higher in animal protein, animal fat, and cholesterol may be associated with protein leakage in the urine (a sign of kidney damage), and generally, diets higher in fruits, vegetables, and whole grains but lower in meat and sweets may be protective against kidney function decline.
In comparison to the diets eaten by our ancestors, not only are we eating more saturated fat, sugar, and salt, we now eat an acid-producing diet, as opposed to a base-producing or alkaline diet. Ancestral human diets were largely plant-based, and, as such, produced more base than acid.
Dietary acid load (DAL) is determined by the balance of acid-inducing food, which is rich in animal proteins (such as meats, eggs, and cheeses) offset by base-inducing foods, such as fruits and vegetables. And, in this national survey of 12,000 American adults, dietary acid load was associated with kidney damage among U.S. adults.
Acid-inducing diets are believed to impact the kidneys via tubular toxicity, damage to the tiny delicate urine-making tubes in the kidneys via increased ammonia production. See, ammonia is a base; so, the kidneys create ammonia to buffer the acid from the food we eat. This is beneficial in the short term to get rid of the acid; however, in the long term, all that extra ammonia in our kidneys day in and day out can exert toxic effects.
Our kidney function tends to decline progressively after our 30’s, and by our 80’s, our kidney capacity may be down to half. Perhaps, this so-called age-related decline in kidney function is a result of damage induced by a lifetime of ammonia overproduction. That’s just one theory, though. The acidic pH may increase the production of free radicals and damage the kidneys that way or add to scarring.
Not only is protein derived from plant foods accompanied by antioxidants that can fight the free radicals, plant protein is less acid forming in the first place, because it tends to have less sulfur–containing amino acids. One of the reasons plant foods tend to be less acid-forming than animal foods is because acid is produced by the sulfur in the protein, and there’s less in plant proteins.
So, the more important determinant of the effect of dietary protein on kidney disease progression is the quality of the ingested protein (in other words, whether it induces acid production like most animal protein, or base production like most fruit and vegetables), rather than the quantity of protein ingested.
Since American diets are largely acid-producing, because they are deficient in fruits and vegetables and contain large amounts of animal products, changing from a standard American diet to a vegan diet may improve acidosis in patients with chronic kidney disease. Under normal circumstances, a vegetarian diet is alkalinizing, whereas a non-vegetarian diet leads to an acid load. This was true even of vegetarians that consumed processed meat replacements like veggie burgers.
Plant-based diets have been prescribed for decades for those with chronic kidney failure. No animal fat, no cholesterol, less acid load, and helps lower blood pressure. And, indeed, if you compare the kidney function of vegans to vegetarians to omnivores, the most plant-based diet was most associated with improved parameters for the prevention of kidney decline.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.
Please consider volunteering to help out on the site.
- A Chang, L Van Horn, D R Jacobs Jr, K Liu, P Muntner, B Newsome, D A Shoham, R Durazo-Arvizu, K Bibbins-Domingo, J Reis, H Kramer. Lifestyle-related factors, obesity, and incident microalbuminuria: the CARDIA (Coronary Artery Risk Development in Young Adults) study. Am J Kidney Dis. 2013 Aug;62(2):267-75.
- T Banerjee, D C Crews, D E Wesson, A Tilea, R Saran, N Rios Burrows, D E Williams, N R Powe; Centers for Disease Control and Prevention Chronic Kidney Disease Surveillance Team. Dietary acid load and chronic kidney disease among adults in the United States. BMC Nephrol. 2014 Aug 24;15:137.
- P Chauveau, C Combe, D Fouque, M Aparicio. Vegetarianism: advantages and drawbacks in patients with chronic kidney diseases. J Ren Nutr. 2013 Nov;23(6):399-405. J Ren Nutr. 2013 Nov;23(6):399-405.
- J Lin, T T Fung, F B Hu FB, G C Curhan. Association of dietary patterns with albuminuria and kidney function decline in older white women: a subgroup analysis from the Nurses' Health Study. Am J Kidney Dis. 2011 Feb;57(2):245-54.
- E van den Berg, F A Hospers, G Navis, M F Engberink, E J Brink, J M Geleijnse, M A van Baak, R O Gans, S J Bakker. Dietary acid load and rapid progression to end-stage renal disease of diabetic nephropathy in Westernized South Asian people. J Nephrol. 2011 Jan-Feb;24(1):11-7.
- N Goraya, J Simoni, C H Jo, D E Wesson. A comparison of treating metabolic acidosis in CKD stage 4 hypertensive kidney disease with fruits and vegetables or sodium bicarbonate. Clin J Am Soc Nephrol. 2013 Mar;8(3):371-81.
- J Lin, F B Hu FB, G C Curhan. Associations of diet with albuminuria and kidney function decline. Clin J Am Soc Nephrol. 2010 May;5(5):836-43.
- W Chen, M K Abramowitz. Metabolic acidosis and the progression of chronic kidney disease. BMC Nephrol. 2014 Apr 3;15:55.
- J J Scialla, L J Appel, B C Astor, E R Miller 3rd, S Beddhu, M Woodward, R S Parekh, C A Anderson. Estimated net endogenous acid production and serum bicarbonate in African Americans with chronic kidney disease. Clin J Am Soc Nephrol. 2011 Jul;6(7):1526-32.
- M J Wiseman, R Hunt, A Goodwin, J L Gross, H Keen, G C Viberti. Dietary composition and renal function in healthy subjects. Nephron. 1987;46(1):37-42.
- N Goraya, D E Wesson. Is dietary Acid a modifiable risk factor for nephropathy progression? Am J Nephrol. 2014;39(2):142-4.
- G Barsotti, E Morelli, A Cupisti, M Meola, L Dani, S Giovannetti. A low-nitrogen low-phosphorus Vegan diet for patients with chronic renal failure. Nephron. 1996;74(2):390-4.
- A Sebastian, L A Frassetto, D E Sellmeyer, R L Merriam, R C Morris Jr. Estimation of the net acid load of the diet of ancestral preagricultural Homo sapiens and their hominid ancestors. Am J Clin Nutr. 2002 Dec;76(6):1308-16.
- P Deriemaeker, D Aerenhouts, M Hebbelinck, P Clarys. Nutrient based estimation of acid-base balance in vegetarians and non-vegetarians. Plant Foods Hum Nutr. 2010 Mar;65(1):77-82.
- E Kanda, M Ai, R Kuriyama, M Yoshida, T Shiigai. Dietary acid intake and kidney disease progression in the elderly. Am J Nephrol. 2014;39(2):145-52.
- J J Scialla, L J Appel, B C Astor, E R Miller 3rd, S Beddhu, M Woodward, R S Parekh, C A Anderson; African American Study of Kidney Disease and Hypertension Study Group. Net endogenous acid production is associated with a faster decline in GFR in African Americans. Kidney Int. 2012 Jul;82(1):106-12.
- J Uribarri, M S Oh. The key to halting progression of CKD might be in the produce market, not in the pharmacy. Kidney Int. 2012 Jan;81(1):7-9.
- B M Brenner, T W Meyer, T H Hostetter. Dietary protein intake and the progressive nature of kidney disease: the role of hemodynamically mediated glomerular injury in the pathogenesis of progressive glomerular sclerosis in aging, renal ablation, and intrinsic renal disease. N Engl J Med. 1982 Sep 9;307(11):652-9.
- J Coresh, E Selvin, L A Stevens, J Manzi, J W Kusek, P Eggers, F Van Lente, A S Levey. Prevalence of chronic kidney disease in the United States. JAMA. 2007 Nov 7;298(17):2038-47.
Images thanks to Hey Paul Studios via Flickr, Pongsak Kaewmanaprasert, Acha Yhamruksa, Sommai Larkjit, Anna Liebiedieva, and Rob Marmion via 123rf, Bambo, OpenPics, PublicDomainPictures, and Lebensmittelfotos via Pixabay, Gajda-13 Fir0002, and Snufkin7 via Wikimedia Commons.
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Protein Source: An Acid Test for Kidney Function
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Content URLDoctor's Note
I was surprised to learn how powerfully diet can affect kidney function and structure. Some of the latest in my kidney series include:
- Which Type of Protein is Better for Our Kidneys?
- How to Prevent Kidney Stones With Diet
- Can Diet Protect Against Kidney Cancer?
Aren’t some plant foods acidic though? Check out the chart in my video How to Treat Kidney Stones with Diet.
Any way to test to see how acid-forming your diet is? Yes—and it’s fun! See Testing Your Diet with Pee & Purple Cabbage.
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