Various things happen after you move in with your significant other. You don’t make as many stir fries as you said you would. You argue over how high the laundry pile gets before it needs sorting out. You give a lecture to your lover about soap scum and its correct removal. You no longer care that much about lingerie. Your immune system changes – wait, what?
A study, published in Nature, discovered that living with a partner changes both your immune systems. In fact, your immune system becomes similar. It’s like a science fiction romantic comedy!
The researchers initially recruited 670 people and took samples to discern the state of their immune systems. 150 of the participants were followed for six months after to observe if their immune systems changed when their environment altered.
However, it was how married couples’ bodies changed that excited the science crowd. The 70 married couples that were part of the study showcased unusual similarities in their immune systems – in fact, they had 50% less variation than other random matches between men and women. (We’re guessing this was a hetero-normative sampling.)
Why do couples’ immune systems start looking so samey? The immunologists behind the study explained that while 25% of your immunity is determined by genes – thank your hardy mam for uneventful flu seasons – 75% falls prey to environmental factors. Your diet and alcohol intake can influence it, as well as your stress levels and sleeping patterns. Because couples spend so much time together, wining/dining/sleeping/not sleeping, their immune systems develop in tandem.
Then there’s the bacteria. Bacteria affects immunity also and couples don’t just share space and saliva, but microbes, meaning they’re going to both experience an impact from that.
Lead study author Adrian Liston, Ph.D. also stressed that non-infectious diseases may also be more ‘shared’ when it comes to coupling. Conditions related to diet and lifestyle, like certain kinds of diabetes and heart disease, have a higher chance of developing when both parties are engaging in shared behaviour.
In conclusion, your love for each other might make you sick, or at least more susceptible to catching the flu together. In sickness and in health, right?