Researchers believe the combination of oxytocin and physical contact promotes wound healing by reducing the body’s stress responses.
A first-in-humans study has found oxytocin and positive relational behaviours may support physical healing, enforcing the neuropeptide’s role as an enhancer rather than outright treatment.
There are many reported health benefits of having close social relationships, many of which can (at least partially) be explained by reducing various physiological stress responses. Improved wound healing is one such benefit.
There are preclinical data suggesting that oxytocin can improve wound healing, and given the neuropeptide’s prosocial effects, it is not surprising to learn that animal studies have explored whether oxytocin can modulate the relationship between social support and wound healing.
Now, for the first time in humans, researchers have shown combining oxytocin with positive behaviours (e.g., affectionate touch, sexual activity) supports improved wound healing.
“These findings suggest that oxytocin amplifies the benefits of intimacy rather than exerting direct effects,” the researchers concluded in JAMA Psychiatry.
“These modest, context-dependent effects provide preliminary insights into the neuroendocrine mechanisms through which intimate relationships can improve health, underscoring the need for larger, more diverse trials.”
Swiss researchers recruited 80 healthy heterosexual couples aged 21-45 who had been in a stable relationship for at least 12 months (average age 27.6 years, average relationship duration 4.0 years).
Participants were excluded if they had extensive skin disease or had been exposed to artificial UV light within the last three months. All participants received standardised blister wounds on their forearms using a combination of suction and heat.
The couples were then randomised into one of four groups accounting for the different potential combinations of receiving intranasal oxytocin versus placebo and completing or not completing the Parter Appreciation Task.
The PAT is a structured discussion where partners talk about aspects of the relationship they value, as well as exchanging gratitude, positive expectations and appreciations with each other.
Oxytocin or placebo were administered approximately one hour after wound application, and then twice daily for the next five days. Participants completed the PAT shortly after the first dose of oxytocin or placebo, then were instructed to complete it up to two additional times at home during the next week. Wound healing was assessed at one hour, 24 hours and seven days after the blister was applied.
Participants who received oxytocin and completed the PAT displayed improved wound healing (assessed by two independent raters using the revised Photographic Would Assessment Tool), while couples who received oxytocin but did not complete the PAT or received placebo but completed the PAT did not.
Additional wound recovery modelling also suggested that oxytocin/PAT couples who engaged greater levels of daily affectionate touch and sexual activity were also predictive of greater wound healing.
“Previous animal data on this topic are mixed, with oxytocin along showing no effect on healing, but [showing] synergistic effects with social interaction in hamsters and with social housing in mice,” the researchers noted.
“At the biological and mechanistic level, both positive couple interactions and oxytocin have been associated with improved immune functioning, suggesting that their interplay may contribute to enhanced wound healing through reductions in cortisol levels and [the] modulation of immune factors.
“However, when considered alongside the immune data from a subsample of this study, immune changes associated with oxytocin and PAT in the previous analysis did not mediate wound healing here.”
The research team did note their study design was limited by only assessing wound healing at 24 hours and seven days post-injury, and that their findings may not generalise outside young, healthy and heterosexual couples.
