Thea Singer has written about health and science for more than three decades. Based in Boston, she is the author of Stress Less (Hudson Street Press/Penguin Group, USA), which reveals how stress ages us down to our DNA, and how to reverse the damage. Learn more at

A major new study claims the pricey supplement TA-65 may turn back the clock, all the way down to our DNA—but many scientists are brushing it off as snake oil. Thea Singer investigates.