Since bones deteriorate with age, it makes sense to take in more calcium as we get older to lower the risk of fractures. But how much is enough?
The latest report from Swedish researchers suggests that for postmenopausal women, anywhere from about 700 to 900 mg of calcium a day is ideal for preventing bone fractures. Higher levels than that had no additional impact on fracture risk. The scientists studied more than 60,000 women who reported their dietary and supplemental calcium intake as well as their fracture rates over 19 years. Women who got less than 750 mg of calcium per day had a 26% higher risk of fracture than women consuming about 900 mg daily, but those who got more--up to 1,185 mg a day--did not lower their risk of fracture any further than those taking 900 mg.
The findings suggest that the calcium consumption recommended for women over 50 by U.S. dietary guidelines--1,200 mg daily--may be too high. It's not that calcium doesn't help promote bone health; it's just that exceeding the threshold may not increase its benefit.
Clues to the Autistic Brain
Could autism have its roots in the womb? That's a strong possibility, according to the latest research that compared gene expression in brains of deceased autistic and normal youngsters. In the analysis, scientists found that autistic brains showed very little difference in gene expression between the frontal and temporal lobes, two regions responsible for language, decisionmaking and emotional responses. In normal children, differences in gene activity between these areas start to appear during fetal development.