However, even when mortality was very high for both sexes, women still lived longer than men by six months to almost four years on average, This advantage in women may be largely due to biological factors such as genetics or hormones, especially estrogens, which enhances the body's immune defenses against infectious disease, the researchers explained. "Our results add another piece to the puzzle of gender differences in survival," said researchers led by Virginia Zarulli, Assistant Professor at the Duke University in Durham, US.
