Research has shown that married couples tend to be more healthier than unmarried couples or single people. 

Research has found that married couples motivate each other to;

• excercise
• avoid unhealthy foods
• socialize more
• discourage smoking and drinking

More information can be found in the - Systematic review and meta analysis of observational studies on Marriage and the risk of dementia / Journal of Neurology, Neurosurgery & Psychiatry

 Link: http://jnnp.bmj.com/content/early/2017/10/30/jnnp-2017-316274 

Time.com Article reflecting the review and analysis of observational studies on marriage and risk of dementia conducted by the Journal of Neurology. Neurosurgery & Psychiatry 

Link: http://time.com/5040061/marriage-prevent-dementia

 

Note: the above article from the Journal of Neurology, Neurosurgery & Psychiatry is an Open Access Article with the terms of the Creative Commons Attribution (CC BY 4.0) license, which permits others to distribute, remix, adapt and build upon the said work, for commercial use, providing the original work is properly cited. See: http://creativecommons.org/licenses/by/4.0