A new study looked at nearly 2 million Danish couples. It found that women who marry a partner who is seven to nine years younger increase their risk of dying by 20 percent.
To make matters worse, the study says marrying an older man can also shorten a woman's lifespan.
It's unclear why this happens. Researchers say the best option might be to marry a man who is the same age. This study is reported in the Journal Demography.