My cynical view is that healthier people are more likely to attract spouses - in other words, that causality runs in the other direction than the commentaries usually imply.
"Our study’s sample population—mostly white and relatively well-off professional women deciding about marriage in the early 1990s—does limit the conclusions we can draw from it with confidence. For instance, our all-female sample cannot tell us anything about the effects of marriage on men. More rigorous work in this area is needed, since prior research indicates that marriage promotes men’s longevity and health even more strongly than women’s."
I'm no sociologist and did not apply any critical analysis to these works, but most of the literature and surveys I found on this topic suggested that men fare worse than women on health outcomes when it comes to marital/romantic singlehood. The speculative cause was that these women possessed deeper friendships than those men, who tended to be more isolated, especially in later stages of life.
Additionally, if I got divorced, I’m pretty sure I won’t marry again and the only close relationships I am likely to have later in life are with my children and possibly grandchildren (if they bless me with any).
Now that I am a bit older and married I deeply appreciate this. It's also another reason to marry someone a bit different than you - they bring you things you need.