Couples in long-term relationships develop weird biological similarities, study finds
When couples reunite and stay together, their bodies synchronize on a deep biological level, according to a new large-scale study by Japanese researchers. This bodes well for couples in happy, physically active relationships, and can lead to improved health into old age. For others, it can produce weird and exacerbated health problems.
The study analyzed health data from tens of thousands of couples – 5,391 from Japan and 28,262 from the Netherlands. In both populations, the researchers found that, in general, long-term partners had similar levels of blood pressure, triglycerides, and cholesterol, and were also more likely to suffer from chronic conditions such as diabetes and diabetes at the same time. ‘hypertension.
The study’s findings echo those of a related study conducted in 2016, when researchers at the University of Michigan at Ann Arbor discovered a similar phenomenon on a smaller scale. Looking at health data from 1,568 older couples in the United States, these researchers found that partners who had been together for more than 50 years had roughly equivalent kidney function and grip strength. This research drew on another set of results from the University of British Columbia, which found that couples in long-term relationships often had concomitant symptoms of psychological illnesses such as depression.
In all of these studies, this health related phenomenon was frequently found in genetically different couples. This has largely ruled out a possible biological explanation related to “assertive mating” – a scientific term that describes the tendency of organisms with similar underlying physical characteristics to mate. Instead, researchers believe lifestyle factors – the daily routines and rhythms of a relationship – end up playing a long-term role in a couple’s health.
“Aging is something couples do together,” said Shannon Meijia, a postdoctoral researcher at the University of Michigan, in a 2016 interview with NPR. “You are in an environment together, you assess that environment together and you make decisions.”
While this deep synchronicity can be harmful in some cases, in others it can be beneficial.
The researchers behind the Japanese study also suggested that their findings could have implications for how doctors diagnose diseases and assess the health of their elderly patients. By examining the health of a spouse, doctors may be able to glean important clues about the health of their patients, and in doing so, suggest preventative measures to soothe future health problems.
Another study, conducted by researchers at Michigan State University, found even more tangible corollary health benefits between couples. Their 2014 article described a four-year project, in which 2,754 older couples in the United States were asked to self-report information about their health while also rating their general level of optimism. Researchers found that relatively fewer cases of arthritis and diabetes were present when at least one partner had a naturally optimistic disposition. In other words, positivity was not only good for an individual’s health – a somewhat mystifying but widely established fact – but it also benefited their spouse.
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