Longitudinal study of dietary patterns and hypertension in adults: China Health and Nutrition Survey 1991–2018

Cardiovascular disease is the leading cause of death in China, accounting for approximately 44% and 47% of total deaths in urban and rural areas in 2019. High blood pressure is a major modifiable risk factor with high exposure prevalence, and China has seen a growing burden of hypertension, with adult prevalence reaching 27.5% in 2018 and substantial increases in mortality attributable to hypertension from 1990 to 2019. Unhealthy diet is an important determinant of blood pressure, and dietary interventions are key for prevention and management of hypertension. Dietary pattern analysis provides a holistic approach to evaluate diet–disease relationships. Although MED and DASH patterns are recommended and protective against hypertension, most evidence comes from Western populations and may not generalize to populations with different food cultures. China’s rapid nutrition transition from traditional to more Westernized dietary patterns may contribute to its high hypertension prevalence, underscoring the need for locally relevant evidence. The study aimed to investigate, over 28 years of follow-up, the longitudinal association between empirically derived dietary patterns and blood pressure and hypertension among Chinese adults in the China Health and Nutrition Survey.

Prior research has identified various dietary patterns associated with blood pressure and hypertension, including protective effects of the Mediterranean and DASH diets, which have been adopted in many countries. However, most studies have been conducted in Western populations, limiting generalizability to Asian contexts with distinct food cultures and eating habits. In China, existing studies on dietary patterns and hypertension have largely been cross-sectional or provincial, highlighting the need for long-term, nationally representative longitudinal analyses to clarify associations in the context of ongoing nutrition transition toward Westernized diets.

Design and data source: Longitudinal analysis using the China Health and Nutrition Survey (CHNS), an ongoing, multistage, random-cluster household-based survey initiated in 1989 across 15 provinces/municipalities varying in demography and development. Ten waves used: 1991, 1993, 1997, 2000, 2004, 2006, 2009, 2011, 2015, 2018. Participants: Adults aged ≥18 years with at least two survey waves providing questionnaires and anthropometrics. From 20,439 adults, exclusions were pregnant/lactating women (n=146), hypertensive at baseline (n=4,233), and implausible energy intake (<800 or >6000 kcal/day for men; <600 or >4000 kcal/day for women) (n=131), yielding 15,929 participants and 64,016 observations. Diet assessment: In each wave, diet measured using household weighing plus three consecutive 24-hour recalls (2 weekdays, 1 weekend day); condiment inventories measured. Average intake across 3 days computed. Intakes aggregated into 18 foods/food groups (g/day) per Chinese Food Composition Table. Derivation of dietary patterns: Factor analysis conducted on combined datasets across years for the 18 food groups; varimax rotation. Number of factors determined by eigenvalues >1, scree plot, and interpretability. Factor loadings calculated; factor scores computed for each participant as weighted sums of food group intakes by loadings. Participants categorized into quartiles of each dietary pattern score. Blood pressure and hypertension: BP measured by trained physicians using mercury sphygmomanometers after 5 minutes seated rest; three measurements with 30-second intervals; average of last two used. Hypertension defined as SBP ≥140 mm Hg or DBP ≥90 mm Hg, or current antihypertensive treatment, or prior physician diagnosis. Covariates: Age, sex, living area (urban/rural), education level, individual income, physical activity, smoking status, alcohol consumption, total energy intake, sodium intake, and BMI; anthropometrics measured by trained staff following WHO protocols; sociodemographic/behavioral data collected via standardized questionnaires. Statistical analysis: Descriptive comparisons across quartiles via chi-square (categorical) and ANOVA (continuous). Three-level mixed-effects linear regression models to estimate associations of dietary pattern quartiles with SBP and DBP; three-level mixed-effects logistic regression models to assess odds of hypertension. Models adjusted for listed covariates. Regression coefficients (β) with 95% CIs and odds ratios (ORs) with 95% CIs reported. Two-tailed tests with significance at P<0.05. Software: SAS 9.4 and Stata/SE 15.

- Sample: 15,929 adults (64,016 observations) followed across 10 waves from 1991–2018. - Dietary patterns identified by factor analysis: 1) Southern pattern: high rice, vegetables, pork (traditional South China diet). 2) Modern pattern: high fruits, dairy products, cakes/cookies/pastries, eggs, nuts/seeds, fungi/algae; some fast foods. 3) Meat pattern: high poultry, organ meats, other livestock meat; also associated with red/processed meats. - Blood pressure outcomes (fully adjusted): - Modern pattern: associated with lower SBP; top quartile vs. lowest β = −0.51 mm Hg (95% CI −0.86, −0.16; P<0.01). - Meat pattern: associated with higher DBP; top quartile vs. lowest β = +0.31 mm Hg (95% CI 0.08, 0.53; P<0.01). - Southern pattern: not significantly associated with SBP or DBP. - Hypertension risk (fully adjusted): - Meat pattern: higher odds of hypertension; top quartile vs. lowest OR = 1.14 (95% CI 1.03–1.24; P<0.01). - Southern and modern patterns: no significant association with hypertension risk. - Participant characteristic gradients across quartiles were observed for age, education, urban residence, income, energy and sodium intake, physical activity, BMI, and baseline BP, consistent with sociodemographic differences in dietary pattern adherence.

In this 28-year longitudinal cohort of Chinese adults, adherence to a meat-centric dietary pattern was positively associated with higher diastolic blood pressure and increased odds of hypertension, independent of demographic, lifestyle, and dietary confounders. In contrast, higher adherence to a modern pattern characterized by fruits and dairy products was associated with lower systolic blood pressure, while the traditional southern pattern showed no significant association with blood pressure or hypertension. These findings align with evidence that animal- and red/processed-meat–rich diets may adversely affect blood pressure, whereas diets richer in fruits and dairy can be beneficial. Given China’s ongoing nutrition transition and increasing prevalence of meat-heavy diets, the results carry important public health implications for dietary guidance tailored to the Chinese context. The long follow-up, repeated dietary and BP assessments, and mixed-effects modeling provide robust evidence addressing prior gaps dominated by cross-sectional or regionally limited studies.

Over nearly three decades of follow-up in the CHNS, a meat dietary pattern was associated with higher DBP and increased hypertension risk, whereas a modern pattern high in fruits and dairy was associated with lower SBP; the southern traditional pattern showed no significant relation to BP or hypertension. These findings support food-based dietary guidance emphasizing increased fruits and dairy and limiting meat-heavy eating patterns for hypertension prevention and management in China. Future research should include prospective and mechanistic studies in diverse Asian populations to clarify causal pathways and evaluate the impact of nutrition transition and Westernization of diets on blood pressure and hypertension.