Abstract
Potential metabolic influences of dietary acid load on bone health have been discussed controversially. Here, we review the available findings in adults and healthy children regarding certain methodological aspects including (i) appropriate use of urinary biomarkers – potential renal acid load (PRAL) and net acid excretion (NAE), (ii) problems in the interpretation of results on calcium balance and bone turnover markers, and (iii) possible influences of selection bias regarding baseline diets of the population groups of randomized controlled trials. Based on the available evidence, it is concluded that calcium balance measurements and bone turnover markers are no adequate and sensitive tools to evaluate the modest but long-term prevailing influence of nutrition on bone status. Findings in children and adults exclusively conducted on the most reliable outcomes, that is, bone densitometric structure analyses, suggest that a low-PRAL diet may be especially relevant in certain population groups, for example, in children with higher dietary protein intakes, in postmenopausal women with impaired bone status, and probably in adults on a habitually acidifying nutrition. The mechanisms mediating detrimental bone effects of higher dietary acid loads under discussion include changes in endocrine–metabolic milieu, for example, impairment of GH/IGF-1 axis and higher glucocorticoid secretion as well as direct bone–cell-related changes by higher acid load. In conclusion, to identify moderate alterations in bone status exerted through nutritional influences, not only appropriate assessments of dietary proton load but also outcome measurements that are closely related to long-term bone structure are required.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Abbreviations
- BMD:
-
Bone mineral density
- DEXA:
-
Dual-energy X-ray absorptiometry
- NAE:
-
Net acid excretion
- NEAP:
-
Net endogenous acid production
- OA:
-
Organic acids
- pQCT:
-
Peripheral quantitative computed tomography (pQCT)
- PRAL:
-
Potential renal acid load
- RCT:
-
Randomized controlled trial
References
Remer T, Manz F. Estimation of the renal net acid excretion by adults consuming diets containing variable amounts of protein. Am J Clin Nutr. 1994;59(6):1356–61.
Groen BB, Res PT, Pennings B, Hertle E, Senden JM, Saris WH, et al. Intragastric protein administration stimulates overnight muscle protein synthesis in elderly men. Am J Physiol Endocrinol Metab. 2012;302(1):E52–60.
Darling AL, Millward DJ, Torgerson DJ, Hewitt CE, Lanham-New SA. Dietary protein and bone health: a systematic review and meta-analysis. Am J Clin Nutr. 2009;90(6):1674–92.
Kalhoff H, Manz F. Nutrition, acid–base status and growth in early childhood. Eur J Nutr. 2001;40(5):221–30.
Proctor DN, Balagopal P, Nair KS. Age-related sarcopenia in humans is associated with reduced synthetic rates of specific muscle proteins. J Nutr. 1998;128(2 Suppl):351S–5.
Remer T, Krupp D, Shi L. Dietary protein’s and dietary acid load’s influence on bone health. Crit Rev Food Sci Nutr. [in press].
Berkemeyer S, Remer T. Anthropometrics provide a better estimate of urinary organic acid anion excretion than a dietary mineral intake-based estimate in children, adolescents, and young adults. J Nutr. 2006;136(5):1203–8.
Remer T, Manz F, Alexy U, Schoenau E, Wudy SA, Shi L. Long-term high urinary potential renal acid load and low nitrogen excretion predict reduced diaphyseal bone mass and bone size in children. J Clin Endocrinol Metab. 2011;96(9):2861–8.
Frassetto LA, Lanham-New SA, Macdonald HM, Remer T, Sebastian A, Tucker KL, et al. Standardizing terminology for estimating the diet-dependent net acid load to the metabolic system. J Nutr. 2007;137(6):1491–2.
Fenton TR, Eliasziw M, Tough SC, Lyon AW, Brown JP, Hanley DA. Low urine pH and acid excretion do not predict bone fractures or the loss of bone mineral density: a prospective cohort study. BMC Musculoskelet Disord. 2010;11:88.
Frassetto L, Morris Jr RC, Sebastian A. Long-term persistence of the urine calcium-lowering effect of potassium bicarbonate in postmenopausal women. J Clin Endocrinol Metab. 2005;90(2):831–4.
Lemann J, Litzow JR, Lennon EJ. Studies of the mechanism by which chronic metabolic acidosis augments urinary calcium excretion in man. J Clin Invest. 1967;46(8):1318–28.
Sebastian A, Harris ST, Ottaway JH, Todd KM, Morris Jr RC. Improved mineral balance and skeletal metabolism in postmenopausal women treated with potassium bicarbonate. N Engl J Med. 1994;330(25):1776–81.
Fenton TR, Lyon AW, Eliasziw M, Tough SC, Hanley DA. Meta-analysis of the effect of the acid-ash hypothesis of osteoporosis on calcium balance. J Bone Miner Res. 2009;24(11):1835–40.
Rafferty K, Davies KM, Heaney RP. Potassium intake and the calcium economy. J Am Coll Nutr. 2005;24(2):99–106.
Hunt JR, Johnson LK, Fariba Roughead ZK. Dietary protein and calcium interact to influence calcium retention: a controlled feeding study. Am J Clin Nutr. 2009;89(5):1357–65.
Rauch F, Schonau E, Woitge H, Remer T, Seibel M. Urinary excretion of hydroxy-pyridinium cross-links of collagen reflects skeletal growth velocity in normal children. Exp Clin Endocrinol. 1994;102(2):94–7.
Wallace JD, Cuneo RC, Lundberg PA, Rosen T, Jorgensen JO, Longobardi S, et al. Responses of markers of bone and collagen turnover to exercise, growth hormone (GH) administration, and GH withdrawal in trained adult males. J Clin Endocrinol Metab. 2000;85(1):124–33.
Jehle S, Zanetti A, Muser J, Hulter HN, Krapf R. Partial neutralization of the acidogenic Western diet with potassium citrate increases bone mass in postmenopausal women with osteopenia. J Am Soc Nephrol. 2006;17(11):3213–22.
Macdonald HM, Black AJ, Aucott L, Duthie G, Duthie S, Sandison R, et al. Effect of potassium citrate supplementation or increased fruit and vegetable intake on bone metabolism in healthy postmenopausal women: a randomized controlled trial. Am J Clin Nutr. 2008;88(2):465–74.
Frassetto LA, Hardcastle AC, Sebastian A, Aucott L, Fraser WD, Reid DM, et al. No evidence that the skeletal non-response to potassium alkali supplements in healthy postmenopausal women depends on blood pressure or sodium chloride intake. Eur J Clin Nutr. 2012;66:1315–22.
Tucker KL, Hannan MT, Kiel DP. The acid–base hypothesis: diet and bone in the Framingham Osteoporosis Study. Eur J Nutr. 2001;40(5):231–7.
Macdonald HM, New SA, Golden MH, Campbell MK, Reid DM. Nutritional associations with bone loss during the menopausal transition: evidence of a beneficial effect of calcium, alcohol, and fruit and vegetable nutrients and of a detrimental effect of fatty acids. Am J Clin Nutr. 2004;79(1):155–65.
Kaptoge S, Welch A, McTaggart A, Mulligan A, Dalzell N, Day NE, et al. Effects of dietary nutrients and food groups on bone loss from the proximal femur in men and women in the 7th and 8th decades of age. Osteoporos Int. 2003;14(5):418–28.
Pedone C, Napoli N, Pozzilli P, Lauretani F, Bandinelli S, Ferrucci L, et al. Quality of diet and potential renal acid load as risk factors for reduced bone density in elderly women. Bone. 2010;46(4):1063–7.
Pedone C, Napoli N, Pozzilli P, Lauretani F, Bandinelli S, Ferrucci L, et al. Author reply – quality of diet and potential renal acid load as risk factors for reduced bone density in elderly women. Bone. 2011;48(2):416.
Remer T, Shi L, Alexy U. Potential renal acid load may more strongly affect bone size and mass than volumetric bone mineral density. Bone. 2011;48(2):414–5; author reply 6.
Alexy U, Remer T, Manz F, Neu CM, Schoenau E. Long-term protein intake and dietary potential renal acid load are associated with bone modeling and remodeling at the proximal radius in healthy children. Am J Clin Nutr. 2005;82(5):1107–14.
Fenton TR, Tough SC, Lyon AW, Eliasziw M, Hanley DA. Causal assessment of dietary acid load and bone disease: a systematic review & meta-analysis applying Hill’s epidemiologic criteria for causality. Nutr J. 2011;10:41.
Green J, Maor G. Effect of metabolic acidosis on the growth hormone/IGF-I endocrine axis in skeletal growth centers. Kidney Int. 2000;57(6):2258–67.
Ordonez FA, Santos F, Martinez V, Garcia E, Fernandez P, Rodriguez J, et al. Resistance to growth hormone and insulin-like growth factor-I in acidotic rats. Pediatr Nephrol. 2000;14(8–9):720–5.
Brungger M, Hulter HN, Krapf R. Effect of chronic metabolic acidosis on the growth hormone/IGF-1 endocrine axis: new cause of growth hormone insensitivity in humans. Kidney Int. 1997;51(1):216–21.
Wiederkehr MR, Kalogiros J, Krapf R. Correction of metabolic acidosis improves thyroid and growth hormone axes in haemodialysis patients. Nephrol Dial Transplant. 2004;19(5):1190–7.
Sicuro A, Mahlbacher K, Hulter HN, Krapf R. Effect of growth hormone on renal and systemic acid–base homeostasis in humans. Am J Physiol. 1998;274(4 Pt 2):F650–7.
Maurer M, Riesen W, Muser J, Hulter HN, Krapf R. Neutralization of Western diet inhibits bone resorption independently of K intake and reduces cortisol secretion in humans. Am J Physiol Renal Physiol. 2003;284(1):F32–40.
Yakar S, Rosen CJ, Beamer WG, Ackert-Bicknell CL, Wu Y, Liu JL, et al. Circulating levels of IGF-1 directly regulate bone growth and density. J Clin Invest. 2002;110(6):771–81.
Canalis E, Delany AM. Mechanisms of glucocorticoid action in bone. Ann N Y Acad Sci. 2002;966:73–81.
Arnett T. Regulation of bone cell function by acid–base balance. Proc Nutr Soc. 2003;62(2):511–20.
Geng W, Hill K, Zerwekh JE, Kohler T, Muller R, Moe OW. Inhibition of osteoclast formation and function by bicarbonate: role of soluble adenylyl cyclase. J Cell Physiol. 2009;220(2):332–40.
Street D, Nielsen JJ, Bangsbo J, Juel C. Metabolic alkalosis reduces exercise-induced acidosis and potassium accumulation in human skeletal muscle interstitium. J Physiol. 2005;566(Pt 2):481–9.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2013 Springer-Verlag London
About this chapter
Cite this chapter
Remer, T., Krupp, D., Shi, L. (2013). When Is Low Potential Renal Acid Load (PRAL) Beneficial for Bone?. In: Burckhardt, P., Dawson-Hughes, B., Weaver, C. (eds) Nutritional Influences on Bone Health. Springer, London. https://doi.org/10.1007/978-1-4471-2769-7_9
Download citation
DOI: https://doi.org/10.1007/978-1-4471-2769-7_9
Published:
Publisher Name: Springer, London
Print ISBN: 978-1-4471-2768-0
Online ISBN: 978-1-4471-2769-7
eBook Packages: MedicineMedicine (R0)