Gastrointestinal symptoms and the Mediterranean dietary pattern: secondary analysis of a randomized controlled trial...

Cardiometabolic diseases are a major global health concern, and their development are linked to suboptimal dietary patterns and adverse gastrointestinal (GI) health outcomes and symptoms. Mediterranean dietary patterns are associated with reduced cardiometabolic disease risk and improved quality of life (QoL). The potential impact of the Mediterranean diet on GI symptoms is an important area of inquiry that requires elucidation. This study aimed to evaluate whether a New Zealand-adapted Mediterranean diet (NZMedDiet) affects GI symptom severity in adults at increased cardiometabolic risk, explore the influence of participant characteristics on symptoms, and assess the association between GI symptoms and health-related QoL.

This secondary analysis used data from a randomized controlled trial of a 12-week NZMedDiet and behavioral intervention in adults with increased cardiometabolic risk. Associations were assessed between the gastrointestinal symptom rating scale (GSRS), the 36-Item Short-Form Survey (SF-36)(assessing QoL), and the NZMedDiet, alongside participant characteristics.

A total of 200 participants were enrolled (mean age 49.9 ± 10.9 years; 62% women), with women reporting significantly higher baseline GI symptom severity scores on average across all GSRS domains except reflux (p < 0.05). Māori participants reported higher baseline indigestion and abdominal pain scores compared with New Zealand Europeans (p < 0.01). Compared with controls, participants in the NZMedDiet group had lower GSRS domain scores, with the largest between-group estimated mean difference observed for abdominal pain being -0.27 (95% CI: -0.48 to -0.06; p = 0.01). Moderate associations were observed between GSRS domains and quality-of-life measures, particularly between abdominal pain and the general health domain (r_s  = -0.25; p < 0.001).

The NZMedDiet had a positive impact on GI symptom severity scores and was well tolerated in participants with increased cardiometabolic risk. Improvements in GSRS domains were correlated with moderate improvements in QoL measurements.

https://www.anzctr.org.au/Default.aspx, identifier ACTRN12622000906752 and https://www.isrctn.com/, identifier ISRCTN89011056.