Why do men die earlier than women? The latest research makes it known that the reason could be that men's hearts go into rapid decline when they reach middle age.
The largest study of the effects of ageing on the heart has found that women's
longevity
may be linked to the fact that their hearts do not lose their pumping power with age.
"We have found that the power of the male heart falls by 20-25 percent between 18 and 70 years of age, " said the head of the study, of Liverpool John Moore University in the UK.
"Within the heart there are millions of cells that enable it to beat. Between the age of 20 and 70, one-third of those cells die and are not replaced in men, " said Gold Spink. "This is part of the ageing process. "
What surprises scientist is that the female heart sees very little loss of these cells. A healthy 70-year-old woman's heart could perform almost as well as a 20-year-old one's.
"This gender difference might just explain why women live longer than men, " said Gold Spink.
They studied more than 250 healthy men and women between the ages of 18 and 80, focusing on healthy persons to remove the confusing influence of disease.
The team has yet to find why ageing takes a greater loss on the male heart, said Gold Spink.
The good news is that men can improve the health of their heart with regular exercise. Gold Spink stressed that women also need regular exercise to prevent their leg muscles becoming smaller and weaker as they age.
单选题
The underlined word "longevity" in the second paragraph probably refers to______.