Adherence to healthy lifestyle behaviors was significantly associated with a lower incidence of irritable bowel syndrome (IBS), a large population-based cohort study showed.

Over a mean follow-up of 12.6 years, adhering to one, two, and three to five healthy lifestyle behaviors — never smoking, optimal sleep, high level of vigorous physical activity, high dietary quality, and moderate alcohol intake — was significantly associated with a lower incidence of IBS, even after adjusting for potential confounders (P<0.001 for trend), reported Irene Xin-Yin Wu, PhD, of Central South University in Hunan, China, and colleagues:

• One behavior: adjusted HR 0.79 (95% CI 0.65-0.96)
• Two behaviors: aHR 0.64 (95% CI 0.53-0.78)
• Three to five behaviors: aHR 0.58 (95% CI 0.46-0.72)

In separate analyses of each of the five lifestyle behaviors, never smoking (aHR 0.86, 95% CI 0.76-0.98, P=0.02), a high level of vigorous physical activity (aHR 0.83, 95% CI 0.73-0.95, P=0.006), and optimal sleep (aHR 0.73, 95% CI 0.60-0.88, P=0.001) showed significant independent inverse associations with IBS incidence, they noted in Gut.

No significant independent associations were observed for healthy diet (aHR 0.89, 95% CI 0.77-1.04, P=0.13) and moderate alcohol consumption (aHR 0.89, 95% CI 0.76-1.04, P=0.14), although their effect sizes approached statistical significance.

“To prevent IBS, it is important for primary healthcare providers to take an active role in delivering appropriate interventions to change health behaviors during routine consultations, as they are often the first point of contact for patients accessing the health system,” Wu and co-authors concluded.

Maitreyi Raman, MD, of the University of Calgary in Canada, told MedPage Today that “this was a great study and novel, as it was designed to identify preventive factors against developing new IBS. For prevention, I would favor emphasizing moderate to vigorous physical activity, high sleep quality, and high-quality diet, ideally the Mediterranean dietary pattern, and low intake of ultra-processed foods.”

In sensitivity analyses, only complete abstinence from alcohol was defined as healthy drinking behavior, and a healthy level of physical activity was defined more loosely as moderate physical activity for at least 150 minutes per week, or vigorous physical activity for at least 75 minutes per week, which outperformed moderate-intensity exercise, the researchers explained. “The benefits of exercise, such as reducing intestinal inflammation and regulating the gut microbiota, might explain the underlying mechanisms of its effect on lowering the risk of IBS.”

The causative role of smoking in IBS is a subject of debate, they added. It may be due to delays in “gastric emptying of food and mouth-cecum transit time,” but may also reflect baseline anxiety or depression, and as such, “may be a surrogate for mental health conditions and mediate the association between mental health conditions and the risk of IBS.”

Research linking anxiety, depression, and general mental health comorbidities with new-onset IBS is well established, Raman said. “Improving the gut-brain connection can be achieved through interventions such as yoga, breathing, mindfulness, cognitive behavioral therapy, as well as gut hypnotherapy. Similarly, physical activity can improve mental health comorbidities and decrease disease onset.”

For this study, Wu and colleagues used data from the U.K. Biobank on 64,268 adults ages 37 to 73 (mean age 55.9, 55% women) who did not have IBS at baseline and were enrolled from 2006 to 2010, and followed up until 2022. Participants completed at least two 24-hour dietary recall questionnaires (including alcohol intake assessment). Incident IBS cases were recorded in 1.5%.

The researchers used the patient-completed questionnaires, physical examination, and biological samples to assess participants’ baseline health and lifestyles at one of 22 assessment centers throughout the U.K.

At baseline, 11.8% of participants reported none of the five healthy lifestyle behaviors, 32.1% reported one behavior, 34.1% reported two behaviors, and 21.9% reported three to five behaviors.

Compared with participants who did not partake in any of the five healthy lifestyle behaviors, those who adhered to three to five behaviors were more likely to be younger, female, have a lower body mass index, be married, be employed or self-employed, and less likely to have a family history of IBS. They also had a lower prevalence of depression, anxiety, back pain or joint pain, headaches, asthma, and gastrointestinal infection.

Wu and team noted that study limitations included the exclusion of a large proportion of participants due to limited responses to a web-based digestive health follow-up questionnaire, and potential discrepancies between subjective self-reported sleep and objective sleep measurements.