Back in 1968, Drs. Wachman and Bernstein theorized that the elevated renal acid load from meat, cheese, grains, and phosphate-rich foods may contribute to the development of osteoporosis. [Lancet 1968;1:958-9]. They suggested consuming more vegetables and fruits would reduce the acid load on the body and limit the loss of calcium being lost in the urine to buffer the increased renal acid load. A study by Dr. Dawson-Hughes examined the impact of adding either sodium or potassium bicarbonate supplements to neutralize the increased renal acid load produced by a typical modern diet in 171 subjects age 50 and older. They found both alkalizing supplements reduced urinary calcium and urinary N-telopeptide – a marker for more rapid bone breakdown. Dr. Dawson-Hughes concluded that alkalinizing the urine “… had a favorable effect on bone resorption and calcium excretion. This suggests increasing the alkali content of the diet may attenuate bone loss in healthy older adults.” [J Clin Metab. 2009;94:96-102]. Another study that examined the impact of dietary protein and other factors on bone development in children from 6 to 18 years showed that while higher protein intake was generally associated with stronger bones, the beneficial impact of more protein in the diet was greatly diminished if the diet was lower in alkalinizing minerals (i.e., calcium, potassium, magnesium). [Am J Clin Nutr 2005;82:1107-14].
A study published online by Dr. Jehle and colleagues examined the impact of giving 201 healthy older people (>65y) either 60mEq of potassium citrate or a look alike placebo for two years. All subjects also received supplements of vitamin D and calcium. After 2 years, only those receiving the potassium supplement saw a reduction in their renal acid load and experienced a significant increase in their bone mineral density (BMD). Those receiving the placebo saw no change or modest declines in BMD. [J Clin Endocrin & Metabdoi:10.12/j c.2012-3099]. It is likely then consuming more potassium-rich foods and cutting back on cheese, meats, and phosphate-rich foods and drinks would help alkalinize the blood and urine and likely slow or even partially reverse the loss of bone minerals associated with osteoporosis. While salt has little impact on acid-base balance, it also contributes to increased urinary calcium loss and so should also be limited in diet of those at risk for osteoporosis. Replacing some salt with MSG would also reduce renal acid load and calcium excretion.
Bottom Line: Americans should consume more potassium-rich foods like fruits and vegetables to help stop or reverse bone loss. It is important to cut back on foods like meats, eggs, cheeses, sodas, etc that acidify the blood and urine and contribute to the loss of BMD over time. Those who already have weakened bones may also benefit from replacing even some of the whole grain products in their diets with more potatoes and yams as the latter are much higher in potassium and would reduce their renal acid load and the loss of BMD.
By James J. Kenney, PhD, FACN
Stephanie Ronco has been editing in a professional capacity for the past 10 years. In addition to her work as an editor, Ronco has also served as a ghostwriter and writing tutor. A voracious reader, Ronco loves watching language evolve and change. When she’s not delving into her latest project, Ronco can be found teaching acting classes, performing in community theater, or sailing with her husband.