Lower chronic neck-back with higher planetary health diet adherence

Background: This study aimed to examine the association between adherence to the Planetary Health Diet (PHD) and the prevalence of chronic neck-back pain. Methods: This cross-sectional analysis used baseline data from 97,543 participants in the UK Biobank with complete dietary, outcome, and covariate data. The PHD score was constructed from up to five 24-h dietary recalls. Chronic neck-back pain was defined as self-reported neck/shoulder or back pain in the previous month lasting ≥3 months and interfering with daily activities. Multivariable logistic regression, restricted cubic splines, and subgroup analyses were performed. Results: Overall, 22.5% of participants reported chronic neck-back pain. In the primary analysis, each 10-point increase in the PHD score was associated with lower odds of prevalent chronic neck-back pain (OR = 0.99, 95% CI: 0.97-1.00). In participants aged < 60 years, the association was stronger (OR = 0.97, 95% CI: 0.96-0.99). The highest PHD quartile showed 7% lower odds of prevalent chronic neck-back pain compared with the lowest quartile (OR = 0.93, 95% CI: 0.88-0.98).Effect modification analyses revealed that the protective effect was most pronounced in women aged < 60 years (OR=0.96, 95% CI: 0.94-0.98). Sensitivity analyses using alternative outcome definitions (ICD-10 codes, single-site pain) and exposure thresholds confirmed the robustness of these findings. Conclusions: Higher adherence to the Planetary Health Diet was associated with lower odds of prevalent chronic neck-back pain, particularly among adults aged < 60 years, with an approximately linear dose-response pattern. These findings provide the first prospective evidence that a sustainable, plant-centric dietary pattern may be associated with a lower risk of chronic spinal pain. However, further validation in independent populations is needed before broad clinical application can be recommended.