The incidence of "toyboy" marriages in which the man is younger than his bride has almost doubled in the past 40 years.
More than a quarter of all marriages now involve older women, according to figures released by the Office for National Statistics (ONS) yesterday.
The "toyboy" rate is even higher for unions in which the man is marrying for the first time.
One in three of first-time grooms is now younger than his bride, compared with 15 per cent in 1963.
Analysts said the trend was good news for women as it meant there would be fewer widows in the future.
For men, however, the outlook is less rosy.
Professor Janet Askham of the Institute of Gerentology at King's College London, said: "Men married to younger women may find that they need to carry on working past retirement age in order to provide for older wives, or children and wives from previous marriages."
While the average age gap between men and women has stayed the same since 1963, at a year, the proportion of marriages which buck the trend has increased. In 1963, only 36 per cent of marriages involved an age gap of more than five years but by 1998, more than 50 per cent of newly-wed couples had a significant age gap.
Men in the youngest age groups - under 25 - were more likely to marry older women, while women over 50 were most likely to get together with a generation-gap groom.
While most of the toyboy grooms are just a few years younger than their brides, about 1 per cent of all marriages now involve a woman ten years older than the man.
Professor Askham said: "It may be that biological age has become less important to people - women no longer need to gain status by marrying someone much older than themselves, and marriage is much more of an equal partnership."
And nothing backs up a social trend like a celebrity endorsement.
Actress Demi Moore, 41, is rumoured to be engaged to 25-year-old Ashton Kutcher, while Joan Collins, 70, is enjoying a fifth marriage - to 37-year-old Percy Gibson.Reuse content