High-quality marriages may help protect against obesity by shaping communication between the brain and gut, new research suggests.
The study is described as the first to show how social bonds influence weight and eating behaviours through an integrated pathway involving brain activity, metabolism and oxytocin, sometimes called “the love hormone”.
The findings suggest relationship quality may matter as much to physical health as traditional risk factors such as exercise and diet.
“We’ve known for years that social relationships impact health, with supportive connections increasing survival rates by up to 50 per cent,” said lead author Dr Arpana Church, a neuroscientist at UCLA Health.
“The biological mechanisms explaining this connection have remained elusive. Our study reveals a novel pathway showing how marriage and emotional support literally get ‘under the skin’ to influence obesity risk.”
Researchers at UCLA Health studied nearly 100 participants from the Los Angeles area, collecting data on marital status, body mass index, diet and other factors.
They also carried out brain imaging while participants viewed food images, tested gut bacteria metabolites, measured blood oxytocin levels and assessed perceived emotional support.
Married people with higher emotional support had a lower body mass index and showed fewer food addiction behaviours than married peers with low support.
Brain scans showed greater activity in the dorsolateral prefrontal cortex, the region that helps control cravings and appetite, when they viewed food images.
Unmarried participants, whether highly supported or not, did not show the same brain patterns, possibly reflecting more varied and less consistent support networks.
Social support was also linked to shifts in gut metabolism. Those with stronger support showed beneficial changes in tryptophan metabolites, compounds made by gut bacteria that help regulate inflammation, immune function, energy balance and brain health.
Married participants with strong support had higher oxytocin levels than unmarried individuals.
The team suggests oxytocin may act as a messenger that strengthens brain regions involved in self-control while promoting healthier gut metabolic profiles.
“Think of oxytocin as a conductor orchestrating a symphony between the brain and gut,” said Church.
“It strengthens the brain’s ability to resist food cravings while promoting beneficial metabolic processes in the gut, both of which help maintain healthy weight.”
Church added: “Marriage may serve as a training ground for self-control. Maintaining a long-term partnership requires consistently overriding destructive impulses and aligning with long-term goals, which may strengthen the same brain circuits involved in managing eating behaviour.”
The authors noted limitations: the data were collected at one point in time, so causation cannot be confirmed; most participants were overweight or obese; and married participants tended to be older.
