Studies have traditionally shown that men who never marry are not as healthy as those who tie the knot.

But a sociology professor from Michigan State University said in a study that the difference isn't as great as it used to be.

"Married people are still healthier than unmarried people," lead researcher Hui Liu said, "but the gap between the married and never-married is closing, especially for men."

Liu said never-married men may be reporting better health because they have greater access to social resources and support that historically were found in a spouse.

Further, the research shows that the health status of the never-married has improved for all race and gender groups. The health of married women also improved, while the health of married men remained stable.

"Politicians and scholars continue to debate the value of marriage for Americans," the researchers write in the study, "with some going so far as to establish social programs and policies to encourage marriage among those socials groups less inclined to marry, particularly the poor and minorities."

Also, researchers found, the health of the widowed, divorced and separated worsened from 1972 to 2003, relative to married people.

The findings were reported in the September issue of the Journal of Health and Social Behavior in an article called "The Times They Are a Changin': Marital Status and Health Differentials from 1972 to 2003."