New studies show that these comprehensive lifestyle changes may change gene expression in hundreds of genes in only a few months-“turning on” (up-regulating) disease-preventing genes and “turning off” (down-regulating) genes that promote heart disease, oncogenes that promote breast cancer and prostate cancer, and genes that promote inflammation and oxidative stress. These lifestyle changes also increase telomerase, the enzyme that repairs and lengthens telomeres-the ends of our chromosomes, which control how long we live.