Marriage health claims are inconclusive

“Marriage is more beneficial for men than women,” says The Daily Telegraph, while The Guardian reports: “Divorce not bad for your long-term health”. Both headlines are prompted by a new study looking at the long-term effects of relationships on health.

The study used a UK cohort of people born in 1958, who had their relationship status assessed at various younger ages. At age 44-46, they had examinations, where various health markers where measured, including blood inflammatory and clotting factors, lung function and metabolic syndrome (a collection of risk factors that increases risk of cardiovascular disease). 

Generally, men who never married or cohabited seemed to have the poorest health markers in midlife, compared to men who married and stayed married. Meanwhile, women who married in their late 20s to early 30s tended to have the best health markers in midlife. Strangely, there seemed to be the suggestion that divorcing was “good” for men and women by being associated with reduced risk of metabolic syndrome, compared with staying married.

If you are enjoying (or thought you were enjoying) the single life, then you should take these findings lightly. There is likely to be a complex interaction between personal relationships, health and lifestyle factors, and other life events and influences.

It should also be noted that researchers looked at various health indicators, not actual diseases. Therefore, the study does not provide conclusive answers about how marital status may influence health or the mechanisms behind it.

Where did the story come from?

The study was carried out by researchers from University College London, London School of Hygiene and Tropical Medicine, and London School of Economics and Political Science. The study received funding from the Economic and Social Research Council, and the National Centre for Research Methods node “Pathways, Biosocial Influences to Health”.

The study was published in the peer-reviewed medical journal American Journal for Public Health.

The study was reported widely in the UK media, with some sources focusing on the apparent difference in health outcomes between married men and women, while others discussed the findings relating to divorce and separation.

The reporting was broadly accurate, though the limitations of the study were not discussed. 

What kind of research was this?

This study used data collected from a large ongoing prospective cohort to look at relationship patterns over the course of a lifetime, and how they were associated with health in midlife.

As the researchers say, various studies from different countries have suggested that married people have better overall health than unmarried people. It has also been suggested that somehow changing any health inequalities relating to marital status could improve population health. However, to do this, the mechanisms linking marital status need to be better understood. That is what this study aimed to look into, by examining changes in partnership status over a 21-year period and its association with health indicators in midlife.

The main limitation of this study is that it cannot prove direct cause and effect, or explain the influence that any relationship changes may have been having. There is likely to be a complex interaction between personal relationships and other health, lifestyle and life events and influences.

What did the research involve?

This study used data collected from the British National Child Development Study. This is an ongoing cohort study that included all people born in one week in 1958, and periodically followed them up to adulthood. This study used data collected in four assessments – in 1981 (age 23), 1991 (age 33), 2000 (age 42) and 2002-04 (44-46 years).

Relationship status was recorded at each assessment, and health outcomes measured at the final assessment in 2002-04, when the person had a clinical examination. The markers of health outcomes included looking at inflammatory markers in the blood, measuring lung function, and looking for metabolic syndrome (a collection of risk factors that increases risk of cardiovascular disease). 

In their statistical models looking at how change in relationship status was associated with these various disease markers, they took into account various early life and early adulthood characteristics. This included things such as socioeconomic status and parental occupation, education, health, disability and cognitive status in childhood years.

The overall analysis, including those with complete data, was based on 10,226 people (5,256 women and 4,970 men).

What were the basic results?

The researchers split men and women into six groups, according to their partnership status. The most common group of men (62%) were those who married in their 20s or early 30s and had remained married. For women, 42% married in their early 20s and remained married; the next most common group (23%) married later, in their late 20s or early 30s, but remained married. 

Findings in men

Men who never married or cohabited (accounting for 11% of those studied) had generally poorer health markers compared with the most common group of men who married or stayed married. This included poorer lung function and higher levels of certain inflammatory markers and blood clotting factors. Men who had cohabited but not married (8%) also had poorer lung function than those who stayed married. Meanwhile, the 8% of men who married and then divorced and didn’t remarry were less likely to have metabolic syndrome compared with men who remained married. 

Findings in women

In women, the second most common group, who married in their late 20s or early 30s, had the best health. They had lower levels of a blood clotting factor and better lung function than those who married earlier. Meanwhile, women who married but later divorced (9%) were less likely to have metabolic syndrome than the most common group, who married young and stayed married.

How did the researchers interpret the results?

The researchers conclude: “Partnership status over the life course has a cumulative effect on a wide range of objectively measured health indicators in midlife.”

Conclusion

These findings should be taken quite lightly and should not give cause for concern, regardless of marital status. It is very difficult to draw meaningful interpretations from these findings, with the analyses showing mixed results.

Generally, they found that men who never married or cohabited seemed to have the poorest health markers in midlife, compared to men who married and stayed married. Meanwhile, women who married in their late 20s to early 30s tended to have the best health markers in midlife.

Strangely, there seemed to be the unusual suggestion that divorcing was “good” for men and women by being associated with reduced risk of metabolic syndrome, compared with staying married.

However, this study does not prove cause and effect. There are complex interactions between personal relationships, health and lifestyle factors, and other life events and influences. This study is not able to pull this apart and explain the possible underlying reasons for any links between relationship status and the measured health markers.

Importantly, the outcomes measured are only that – a varied collection of blood inflammatory and clotting factors, lung function and metabolic syndrome. These may increase the risk of, or be associated with, actual diseases, but these indicators are not diseases in themselves. For example, the fact that women who married later had lower levels of a particular blood clotting factor and better lung function than those who married earlier on a single assessment day, does not necessarily mean they are all healthier. These midlife health markers may not be good indicators of this cohort’s future health and disease outlook.

Also, this is a specific cohort of people born in 1958. Their marital status and relationship patterns may not be a good parallel for those from other generations, or from other cultures or countries. For example, people in successively younger generations tend to marry later, or may be less likely to marry than those of older generations.

The findings will be of interest in the fields of human sociology and psychology, and will add to the bulk of existing research looking at how marital status may influence health. However, this study alone does not provide conclusive answers about the nature of any relationship or the mechanisms behind it.

Connecting with other people can improve your mental wellbeing, which could also improve physical health, but we wouldn’t recommend rushing down the aisle based on the results of this study.