Fifty years of scientific evidence has shown that the quality of your marriage (or marriage-like relationship) matters for your physical health. Generally, people experiencing marital bliss enjoy better health and live longer than the miserably married, and researchers have long searched for possible explanations.
Poverty is one. Financial stress wrecks havoc on relationships, and lower socioeconomic status often means poorer access to medical care, fewer healthy food options, worse working conditions, less safe neighborhoods, and poorer sleep, to name a few.
Beyond the societal and economic factors, a toxic marriage fuels stress. Fighting with a partner raises blood pressure1 and changes the immune system4 in ways that, in the long term, may contribute to cardiovascular disease and accelerate aging.
However, if you are going through a rough patch in your marriage, don’t panic (lest you further raise your blood pressure). Much like the effects of your everyday diet and physical activity, the heavier-hitting health consequences of marital strife will likely not set in right away. Eating a greasy hamburger when you otherwise consume leafy, green vegetables and raw grains will not instantly clog your arteries. Instead, it is the chronic repetition of an unhealthy pattern over weeks, months, and years that makes a difference.
But this also begs the question: If you want to improve your health, will restoring your marriage to the starry-eyed honeymoon phase get you there? Not necessarily. Research is discovering that a close, happy relationship has its potential pitfalls, too.
How so? In sharing life, partners’ moods become contagious, and routines coincide. These connections may be even stronger for closer, happier couples, and what’s being shared is not guaranteed to benefit either partner’s health.
For example, in a study of people with painful knee arthritis, spouses slept worse on days when patients experienced more pain—even more so in couples who rated their relationship as very close. In another study of people with chronic pain and their spouses, wives who were more happily married felt even more distress when they saw their husbands suffering compared to wives in less satisfying marriages.
This crossover is not limited to pain. In general, couples that spend more time together tend to have more similar activity levels, for instance. In addition, a recent study found that couples that were happier in their relationship also frequently ate together and slept in the same bed. However, these couples did not necessarily engage in healthier routines. Other work showed that closer, happier couples had more similar blood pressure, blood glucose levels, and even more similar metabolisms compared to less close, less happy couples. This was true for healthy and unhealthy couples alike.
What’s more, unhealthy habits may be harder to shake when both partners indulge. One famous study asked couples—one or both of whom smoked cigarettes and had lung or heart disease—to talk about a difficult marital problem and then continue the conversation while smoking a cigarette. When both partners smoked, lighting up not only boosted their moods but also made partners feel more in sync.
The opposite happened when only one of the partners smoked: They felt worse, and more out of sync. In other words, not only did smoking together increase their enjoyment overall, but it brought the partners emotionally closer. This kind of bonding makes smoking more rewarding, and harder to quit.
The same patterns may hold for other health behaviors—activity levels, sleep hygiene, and food choices. For example, in one study, body mass index was highest among women in couples who were emotional eaters, but only when the couple also thought of themselves as a single unit (i.e., a "we," as opposed to "you and me") when it came to their health routines. Even among the emotional eaters, women’s body mass was much lower if the couple did not think about themselves in such close terms. You read that right, ladies: The effect was specific to women.
How to Protect Your Health
What can be done to escape this catch-22? There are several options. As the old saying goes, knowing is half the battle. With the awareness that a loved one's stress and suffering can affect our health (and, likewise, that our stress impacts their health), we can be more proactive about protecting the well-being of everyone involved.
Perhaps your partner spoiled the mood after a bad day at work? First, you should know that giving support to others is good for your health. One experiment found that people randomly assigned to do kind, supportive acts for others had a better immune function at the end of the study compared to those assigned to do nice things for themselves. More evidence that it is often better to give than to receive.
Also, check in with yourself. Feeling tense or anxious about hearing about your partner’s fight with their boss? Try a mindfulness exercise. Or go for a brisk walk with your partner. One study found that couples felt happier in the relationship on days when they had exercised together; this finding held apart from the benefit of exercising alone.
Leveraging the positive effects of contagion can boost your mood, your health, and your relationships. Remember: Every day brings a new opportunity to start (or continue) a healthy routine.