Researchers from the UK’s University of Surrey looked at 14 studies on the effect of alkaline potassium salts on calcium metabolism and bone health.
They said the study was the first to show that these potassium salts reduced bone resorption - the process whereby bone minerals are broken down and released into the blood - therefore increasing their strength.
The study, published in the journal Osteoporosis International, also demonstrated that high intake of potassium salts significantly reduced the excretion of calcium and acid in urine.
Dr Helen Lambert, one of the paper’s lead authors, said: "This means that excess acid is neutralised and bone mineral is preserved."
"Excess acid in the body, produced as a result of a typical Western diet high in animal and cereal protein, causes bones to weaken and fracture. Our study shows that these salts could prevent osteoporosis, as our results showed a decrease in bone resorption."
Yet the researchers said: “The role of acid-base balance as a determinant of bone health, and the potential contribution of potassium, abundant in fruit and vegetables, in promoting skeletal integrity is contentious.”
They said the effects of potassium bicarbonate (KHCO3) and potassium citrate (KCitr) on calcium and acid excretion has not been widely disputed, however the implications of these effects for bone health has been debated.
Bone mineral density and fracture risk
While these results within bone re-absorption and calcium and net acid excretion were positive, data on bone formation and bone mineral density (BMD) and what this means for fracture risk was limited and less conclusive.
“Two of the studies included in our meta-analysis investigated BMD as an end-point, a small number of studies with which to detect an overall effect – indeed we failed to show an effect of supplementation on BMD,” they wrote.
One of these papers noted a marked increase in BMD at the lumbar spine after two years of supplementation with potassium citrate, compared to the placebo placebo group. As a result, fracture risk was significantly reduced in both men and women.
Source: Osteoporosis International
Published online ahead of print, doi: 10.1007/s00198-014-3006-9
“The effect of supplementation with alkaline potassium salts on bone metabolism: a meta-analysis”
Authors: H. Lambert, L. Frassetto, J. B. Moore, D. Torgerson, R. Gannon, P. Burckhardt, S. Lanham-New