Most people are aware of the importance of getting adequate calcium and vitamin D to maintain strong bones and reduce the risk of osteoporosis and broken bones. However, there are other dietary factors that can influence bone metabolism. These factors may increase or decrease the risk of thinning bones in older Americans. Epidemiological studies have found that people who consume more fruits and vegetables tend to have stronger bones.1 In addition numerous studies have shown that increasing dietary salt intake leads to an increased loss of calcium in the urine and an increased serum parathyroid hormone level.2
The DASH-Sodium trial enabled researchers to examine the impact of 3 different levels of dietary salt in either a typical American diet or the DASH diet, rich in whole grains, fruits, vegetables and lowfat dairy products and less meat than most Americans eat. This new study specifically examined the individual and combined impact of different levels of sodium intake and consuming the DASH diet on bone metabolism. Switching from a typical American diet to the DASH diet resulted in about a 10 percent reduction in osteocalcin, a hormone associated with more rapid breakdown of bone. Another marker of bone breakdown was also about 17 percent lower on the DASH diet than the more typical American diet. However, urinary calcium loss was not significantly increased on the American diet compared to the DASH diet. Increasing dietary sodium was associated with a greater loss of calcium in the urine on both the DASH diet and the more typical American diet.
The authors of this study conclude, ?? the DASH diet significantly reduced bone turnover, which if sustained may improve bone mineral status. A reduced sodium intake reduced calcium excretion in both diet groups and serum osteocalcin in the DASH group. The DASH diet and reduced sodium intake may have complementary, beneficial effects on bone health.?3
By James Kenney, PhD, RD, LD, FACN.
1. Am J Clin Nutr 2000; 71:142-51
2. J Bone Miner Res 1996;11:731-6
3. J Nutr 2003;133:3130-6
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.