A Blood Pressure-Lowering Diet for Preventing and Managing Hypertension

This cluster-randomized controlled trial will evaluate whether a 3-month culturally adapted blood pressure-lowering dietary, called the Eastern Blood Pressure-Lowering Diet, can improve blood pressure and related health outcomes in Chinese adults with primary hypertension. Approximately 800 participants from 16 workplace-based clusters will be assigned to either a standard hypertension management group or a dietary intervention group. Both groups will receive usual hypertension care, including health education and medication treatment when clinically indicated. In addition, participants in the dietary intervention group will receive specially designed weekday lunches, low-sodium salt and reduced-sodium seasonings, and app-based support for dietary recording and adherence monitoring. The main outcome is change in resting systolic and diastolic blood pressure. Other outcomes include body weight, waist circumference, body fat, blood glucose, blood lipids, homocysteine, kidney function, estimated 24-hour urinary sodium and potassium excretion, lifestyle behaviors, sleep, psychological well-being, and the occurrence of hypertension-related complications or cardiovascular and cerebrovascular events. Blood, urine, and stool samples will also be analyzed to explore possible metabolic and gut microbiome mechanisms underlying the effects of the dietary intervention. The active dietary intervention will last 3 months, and participants will be followed for up to 24 months.

Inclusion Criteria: * Aged 18 to 60 years. * Employed by Shengli Oilfield and regularly receiving meals from a participating workplace canteen. * Regularly eats at the participating canteen, generally on at least 4 working days per week. * Diagnosed with primary hypertension by a qualified medical institution, or meets the diagnostic criterion of systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg on 3 measurements obtained on different days. * Hypertension is clinically stable. * Antihypertensive medication regimen is stable, when applicable. * Able and willing to comply with the dietary intervention, study assessments, and follow-up procedures. * Provides written informed consent voluntarily. Exclusion Criteria: * Secondary hypertension. * Pregnancy, breastfeeding, or planning to become pregnant during the study period. * Serious food allergy or intolerance to major foods included in the intervention diet, such as nuts, dairy products, or gluten-containing foods. * Major cardiovascular or cerebrovascular event within the previous 6 months, such as myocardial infarction or stroke. * Severe cardiopulmonary disease, such as heart failure or severe asthma. * Cancer, advanced kidney disease, severe liver disease, or another serious medical condition. * A medical condition requiring a specialized therapeutic diet that would interfere with the study intervention. * Severe psychiatric illness. * Severe cognitive impairment that prevents understanding of the informed consent form or compliance with study procedures. * Hearing impairment or physical disability that would substantially interfere with participation. * Any other condition that, in the judgment of the research team, makes the individual unsuitable for participation.