New research finds key to reverse human aging

A new research takes a step further towards unravelling human aging by the discovery of a biological clock that could be the key for studying new therapeutic approaches to keeping people young. University of California Scientist Steve Hovarth has found body parts are aging at different rates through the discovery of a human clock in the body's DNA which measures age of cells, tissues and organs, according to a study published Monday by scientific journal Genome Biology. "I developed a multi-tissue predictor of age that allows one to estimate the DNA methylation age of most tissues and cell types," said Hovarth. The DNA methylation age measures the cumulative effect of an epigenetic maintenance system. This novel epigenetic clock can be used to address a host of questions in developmental biology, cancer and aging research, he said. To create the clock, Horvath focused on methylation, a naturally occurring process that chemically alters DNA. He sifted through 121 sets of data collected previously by researchers who had studied methylation in both healthy and cancerous human tissue. Analysing 8,000 samples of 51 types of tissue and cells taken from throughout the body, he charted how age affects DNA methylation levels from pre-birth through 101 years. To create the clock, he zeroed in on 353 markers that change with age and are present throughout the body. He tested the clock's effectiveness by comparing a tissue's biological age to its chronological age. Repeated tests showed that the clock was accurate. However, the question is "whether the biological clock controls a process that leads to aging," Horvath said. "If so, the clock will become an important biomarker for studying new therapeutic approaches to keeping us young." Theoretically, it is possible to reverse aging if one understands how it is taking place. Horvath's work is a clear identification of a biochemical process linked to aging. By understanding how the body clock works, it may be possible to get the key to aging, and perhaps develop ways of stopping or slowing it down. The results may explain why breast cancer is the most common cancer in women. Given that the clock ranked tumor tissue an average of 36 years older than healthy tissue, it could also explain why age is a major risk factor for many cancers in both genders, the study said. "Healthy breast tissue is about two to three years older than the rest of a woman's body," said Horvath. "If a woman has breast cancer, the healthy tissue next to the tumor is an average of 12 years older than the rest of her body." (QNA)