ARS | Publication request: STANDARDIZING TERMINOLOGY FOR ESTIMATING THE DIET-DEPENDENT NET ACID LOAD TO THE METABOLIC SYSTEM

Submitted to: Journal of Nutrition
Publication Type: Other
Publication Acceptance Date: March 22, 2007
Publication Date: June 1, 2007
Citation: Frassetto, L.A., Lanham-New, S.A., Macdonald, H.M., Remer, T., Sebastian, A., Tucker, K., Tylavsky, F.A. 2007. Standardizing terminology for estimating the diet-dependent net acid load to the metabolic system. Journal of Nutrition. 137:1491-92.

Technical Abstract: Contemporary Western diets contain acid precursors in excess of base precursors, yielding a daily systemic net acid load of varying amounts, depending on the specific composition of the diet. Increasing evidence suggests that differences in daily net acid load, resulting predominantly from differences in dietary intake, can have deleterious health consequences, with a stepwise increase in severity with increasing magnitude of the net acid load. The daily net acid load’s magnitude (in part by influencing systemic acid-base status) has been shown to induce renal losses of calcium, magnesium, and nitrogen and adversely affects numerous endocrine functions. Investigations have shown detrimental clinical outcome effects, particularly for axial and peripheral bone health in elderly subjects and postmenopausal women as well as healthy children. While physiological and biochemical principles support negative effects on bone architecture, muscle wasting and nephrolithiasis, quantifying clinical outcomes is not straightforward. The long latency period required for subclinical changes to be clinically relevant, and the lack of precision of current technology, have posed challenges for researchers. For example, dual energy x-ray absorptiometry does not allow detection of moderate changes in architectural-related bone strength parameters thus requiring long-term follow-up or large sample sizes. Additionally, terminological confusions result from investigators’ use of different algorithms for estimating the diet’s daily net acid load, even when the estimates derive essentially from the same input variables. For this reason, a number of Plenary Speakers at the 2nd International Acid-Base Symposium held in Munich, (8-9th September 2006) agreed to try to reach agreement on terminology related to estimating the diet’s daily net acid load from the composition of the diet, based on accepted physiological principles.