Yoga before obesity surgery linked to lower stress hormone in small Italian study

A small study from Milan, Italy, published this month in the journal Frontiers in Public Health, found that adults with severe obesity who took part in a three-month yoga programme while waiting for bariatric (weight-loss) surgery had lower blood levels of the stress hormone noradrenaline than a comparison group who did not. The findings were summarised in a research report dated Monday, 12 October 2026. The same study found no clear change in markers of inflammation at the gene level and no clear psychological or metabolic benefit, and its authors stress that the design cannot prove yoga caused the difference.

The months before bariatric surgery are a demanding period. Patients usually face assessments, diet changes and the stress of a major operation. Noradrenaline is one of the chemical messengers of the sympathetic nervous system, the body's "fight or flight" response, and its blood level is one way researchers track how activated that system is. The authors read the lower level in the yoga group as consistent with reduced sympathetic activation during a stressful phase of care.

The study also tested a more ambitious idea: that yoga might change how inflammation genes are regulated, through chemical tags on DNA known as methylation. Severe obesity is linked to low-grade, long-lasting inflammation, so an effect here would have been notable. The team did not find one. They suggested that the short intervention period, the small sample and the use of blood samples alone may have limited their ability to detect such changes.

For readers who follow evidence on yoga, the paper is a useful example of how a cautious result looks. The positive finding sits on a secondary outcome, in a non-randomised group of 40 people at a single centre, where participants picked their own group. People who volunteer for yoga may differ from those who do not in ways that also affect stress hormones. The authors themselves say the design does not allow conclusions about cause and effect, and that adverse events were not recorded systematically.

Short-term: The result gives no grounds for surgical teams to change pre-operative care. It does support running a properly randomised trial of yoga before bariatric surgery, with stress hormones as a planned main outcome.

Long-term: If larger randomised studies confirm the effect, supervised yoga could become a low-cost addition to the preparation programmes that many bariatric centres already run, alongside diet and exercise advice. If they do not, the finding will join many small pilot results that faded under stricter testing.

Who is affected: People with severe obesity preparing for weight-loss surgery, bariatric and anaesthesia teams, yoga therapists working in hospital settings, and researchers designing trials on mind-body practices.

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