(P23-010-25) Adherence to Planetary Health Diet, Environmental Impacts, and Hypertension Risk: A Prospective Cohort Study From the China Health and Nutrition Survey

Objectives: We investigated the association between adherence to the Planetary Health Diet (PHD) and hypertension risk among Chinese adults with predominantly plant-based diets.

Methods: We included 16,124 adults aged 18-80 years from the China Health and Nutrition Survey (1991-2015) who were free from hypertension, diabetes, cardiovascular diseases, and cancer at baseline. Dietary intake was assessed repeatedly using individual-level 3-day 24-hour dietary recalls supplemented with household-level weighing methods in each survey. The planetary health diet score (PHDS), developed for a Chinese population residing in Singapore, and the planetary health diet index (PHDI), primarily developed for western populations, were employed to evaluate adherence to PHD. Hypertension was ascertained via blood pressure measurement, previous medical diagnosis, or current use of antihypertensive medication. Multivariable Cox proportional hazards regression models were utilized to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results: During a median follow-up of 11.1 years, we documented 5,367 incident hypertension cases. PHDI was not significantly associated with hypertension (HR_{Quartile4 vs. Quartile1}  = 0.98; 95% CI, 0.90-1.07), whereas higher PHDS was associated with a lower risk of hypertension (HR_{Quartile4 vs. Quartile1} = 0.80, 95% CI, 0.74-0.88; P-trend < 0.001). When stratified by smoking status or occupational physical activity level, the inverse association was significant only among non-smokers (P-interaction = 0.02) and participants with low or moderate levels of occupational activity (P-interaction = 0.006). However, higher PHDS was related to higher greenhouse gas emissions (β=0.39 kg CO₂ equivalent; 95% CI, 0.37 ~ 0.40 kg CO₂ equivalent), water use (β=0.41 m³; 95% CI, 0.38 ~ 0.43 m³), and land use (β=0.42 m²; 95% CI, 0.39 ~ 0.46 m²), whereas higher PHDI was related to lower water use (β=-0.12 m³; 95% CI, -0.15 ~ -0.09 m³) and land use (β=-0.27 m²; 95% CI, -0.32 ~ -0.23 m²).

Conclusions: The two proportional scoring systems representing the PHD exhibited differences in their construction, applicability, and association with both hypertension and environmental outcomes. Thus, it is crucial to develop scoring systems that can accurately represent PHD within the Chinese population in future studies.

Funding Sources: No funding