Couples who live and raise a child together develop similar immune systems, says a new study.
There are many things to consider when deciding to have a baby together. Adding another person to your coupledom will affect everything from your relationship dynamic and your finances to your lifestyle and your immune system.
Wait, what was that last one?
According to a new European study, cohabiting and raising a child with another person causes greater changes to the immune system than illnesses like gastroenteritis or vaccines like the one for the flu.
How can this be possible?
Researchers examined 670 people between the ages of 2 and 86 over three years, measuring how things like gender, obesity, anxiety, and depression impacted their immune systems. It turns out, not very much (although age was found to be a crucial factor). But what they did find was that one of the most influential factors on the immune system was whether or not a person was co-parenting a child with someone else under the same roof.
"[T]he largest influence on immunological variation identified was cohabitation, with 50 percent less immunological variation between individuals who share an environment (as parents) than between people in the wider population," the authors wrote. "These results identify local environmental conditions as a key factor in shaping the human immune system."
It sounds crazy. But I guess when you break it down it's not really all that surprising that people raising a kid together have more similar systems, especially when you consider that parents who live together are probably more inclined to eat the same foods, follow the same sleep schedule, and expose themselves to the same bacteria.
"Since parenting is one of the most severe environmental challenges anyone willingly puts themselves through, it makes sense that it radically rewires the immune system," said Dr. Adrian Liston, an author of the study, via press release. "Still, it was a surprise that having kids was a much more potent immune challenge than severe gastroenteritis. That's at least something for prospective parents to consider—the sleep deprivation, stress, chronic infections, and all the other challenges of parenting does more to our body than just give us gray hairs. I think that any parents of a nursery- or school-age child can appreciate the effect a child has on your immune system!"