单项选择题
| The age-old riddle of why many women
live longer than men has been solved. It’s their pumping power, British
researchers have found. On average, women live five years longer than men and women over the age of 60 are now the fastest-growing section of the British population. The average male heart becomes weaker with age, and by the age of 70 its power to pump blood around the body could have decreased by up to a quarter of its youthful strength. David Goldspink, Professor of Cell and Molecular Sports Science at Liverpool John Moores University, said yesterday that women’s longevity is linked to the strength of their hearts. Unlike men, they pump just as strongly at 70 as they do at 20. "We have found that the power of the male heart falls by 20 -25 percent between 18 and 70 years of age," Professor Goldspink said. "In stark contrast, over the same period there was no age-related decline in the power of the female heart, meaning that the heart of a healthy 70-year-old woman could perform almost as well as a 20-year-old’s." The dramatic difference between the sexes might explain why women live longer. The good news is that men of any age can improve the health of their hearts simply by taking more regular exercise. |