Acid-base balance of the diet: implications for bone

Authors: DAWSON-HUGHES, BESS - Jean Mayer Human Nutrition Research Center On Aging At Tufts University

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 8/26/2015
Publication Date: 8/17/2016
Citation: Dawson-Hughes, B. 2016. Acid-base balance of the diet: implications for bone. In: Weaver, C.M. et al, editors. Nutritional Influences on Bone Health. Switzerland: Springer International. doi: 10.1007/978-3-319-32417-3_9.

Interpretive Summary:

Technical Abstract: With aging, men and women develop a mild and progressive metabolic acidosis. This occurs as a result of the combination of declining renal function and ingestion of acid-producing diets. Acid-producing diets are generally low in fruits and vegetables in relation to their content of cereal grains and protein. There is extensive evidence that severe metabolic acidosis causes bone loss, but the impact of the chronic, low-grade acidosis on bone mass and fracture risk in older individuals has not been established and remains controversial. In a recent dose-finding trial in healthy older men and women, the dose of 81 mmol/d of potassium bicarbonate (KHCO3) produced the greatest reduction in urinary excretion of N-telopeptide (NTX), a biochemical marker of bone resorption over a 3-month period. Findings from the two available placebo-controlled, 2-year alkali intervention trials are conflicting, with one null and the other indicating favorable effects of potassium citrate on rates of bone loss and on trabecular bone density. Reductions in bone turnover markers and calcium excretion in the absence of changes in calcium absorption have been observed in short-term studies. Further work is needed to assess the long-term skeletal effects of lowering dietary acid loads.