life expectancy for older women has fallen after decades of rises as unhealthy lifestyles and cuts to social care take their toll .
by 2013 , the average 75-year-old woman could expect to live another 13 years and longer .
if the change becomes a trend , it could mark the end of an expectation by baby boomers that they will continue to live longer and longer .
life expectancy has increased by 1.2 per cent for men aged 65 and 0.7 per cent for women .