A hormone secreted by bones appears to reverse age-related memory loss. Exercise boosts the production of this hormone, suggesting that lifting heavy objects may protect the brain from age-related damage. Eric Kandel, of Columbia University, and colleagues, became interested in the mechanisms that lead to the usually age-related memory loss, according to New Scientist UK. They measured levels of messenger ribonucleic acid (mRNA) associated with the expression of 23,000 genes in the human brain. Genes use mRNA to tell cells to make products such as proteins – so mRNA levels reflect how active a gene is before it dies. This team focused their analysis on the dentate gyrus, according to the report. This area of the brain is particularly affected by memory loss as we age. The brain tissue came from eight healthy subjects between the ages of 33 and 88. The activity of a gene known as RbAp48 in these individuals declined with age. This gene is known to be involved in the process of converting short-term memories into long-term ones. The results of Kandel’s team’s work further suggest that there is a relationship between RbAp48 and osteocalcin, a hormone secreted by bones, the report said. Osteocalcin has a number of functions, one of which appears to be related to cognition – rodents with mutations that result in deficiencies of this hormone in the body have memory deficits. The result of this study is that osteocalcin, which is produced by bone, appears to be critical to memory health. The conclusion is supported by the fact that age-related osteoporosis – where bones lose strength and produce less osteocalcin – is associated with memory loss. Osteocalcin typically decreases with bone mass throughout our lives, the report said. However, Kandel says exercise may be able to stop this.