A groundbreaking study from Sun Yat-sen University's School of Public Health has illuminated the intricate metabolic mechanisms through which the Chinese Heart-Healthy (CHH) diet lowers blood pressure. Led by Professor Huilian Zhu, the research team delved into untargeted metabolomic profiling of serum and urine samples from a randomized feeding trial, uncovering biologically plausible pathways that explain the diet's cardiovascular benefits. This discovery not only validates the efficacy of culturally tailored dietary interventions but also opens new avenues for precision nutrition in hypertension management.

The DECIDE-Diet trial, a multicenter effort involving 265 Chinese adults with systolic blood pressure between 130 and 159 mm Hg, compared the CHH diet to a control diet over 28 days. Participants followed provided meals strictly, ensuring high adherence and rigorous control over dietary variables. The CHH diet, adapted from four traditional Chinese cuisines—Beijing, Sichuan, Cantonese, and Huaiyang—features halved sodium intake (approximately 3,000 mg/day versus 6,000 mg in typical diets), increased fruits, vegetables, whole grains, legumes, nuts, low-fat dairy, and seafood, while reducing red meat, oils, and processed foods. This composition boosts soluble fiber, protein, potassium, calcium, and magnesium, aligning with global heart-healthy patterns like DASH but rooted in Chinese culinary traditions.

Building on Prior Evidence: The Evolution of CHH Diet Research

Prior studies laid the foundation for this metabolomics breakthrough. A 2022 multicenter trial published in Circulation demonstrated the CHH diet reduced systolic blood pressure by about 10 mm Hg and diastolic by 3.8 mm Hg in similar populations, proving its palatability and cost-effectiveness. Subsequent analyses showed improvements in blood lipids and glucose, underscoring broad cardiometabolic benefits. Sun Yat-sen University's involvement highlights its leadership in nutrition science, with Professor Zhu's lab focusing on diet-health links since the early 2000s, including choline, betaine, and methyl donors' roles in chronic disease prevention.

China faces a hypertension crisis, with prevalence around 30-47% in adults per recent 2026 surveys—over 270 million cases—and control rates lagging at 15%. Traditional diets shifting toward high-sodium processed foods exacerbate this; the CHH model counters it by preserving cultural appeal while optimizing nutrients.

The DECIDE-Diet Trial: Rigorous Design and Execution

Conducted across multiple sites, the trial's single-blind, parallel-controlled design minimized bias. Baseline metabolomics captured pre-intervention profiles, with post-28-day samples analyzed via high-throughput mass spectrometry. Linear mixed models and partial least-squares discriminant analysis identified 52 serum and 101 urinary metabolites changing differentially (VIP >1.0, FDR-adjusted P<0.05). Pathway enrichment prioritized those relevant to blood pressure regulation, revealing fatty acid oxidation and tryptophan metabolism as pivotal.

Key Metabolomic Discoveries: From Data to Pathways

Seventeen prioritized metabolites linked to systolic blood pressure (SBP) changes mediated 33.3% of the CHH diet's SBP-lowering effect (3.3 mm Hg) and 47.2% of diastolic blood pressure (DBP) reduction (1.8 mm Hg). Four stood out: three medium-chain acylcarnitines—2-octenoylcarnitine, 5-methylheptanoylcarnitine, and (2Z,4E,6Z)-decatrienoylcarnitine—decreased with CHH, enriching fatty acid oxidation and correlating positively with SBP. Tetrahydrobiopterin rose, tied to tryptophan metabolism, inversely associated with SBP.

These shifts were driven by nutrient changes beyond sodium/potassium—higher fiber and plant foods likely enhanced beta-oxidation while boosting tryptophan-derived vasodilators.

Fatty Acid Oxidation: Burning Fat to Ease Vascular Strain

Fatty acid oxidation (beta-oxidation) breaks down fats in mitochondria for energy, producing acylcarnitines as shuttles. Excess medium-chain acylcarnitines signal incomplete oxidation, promoting lipotoxicity and endothelial dysfunction—key hypertension drivers. The CHH diet's fiber-rich, low-fat profile reduced these by 17.4% mediation on SBP, suggesting improved mitochondrial efficiency alleviates vascular stress. Step-by-step: 1) Dietary fats enter cells; 2) Carnitine acyltransferase forms acylcarnitines; 3) Mitochondrial transport and beta-oxidation yield ATP, acetyl-CoA; 4) CHH lowers overload, reducing BP-promoting inflammation.

Photo by National Cancer Institute on Unsplash

• 9 metabolites in this pathway mediated major effects.
• Links to prior evidence: Impaired beta-oxidation elevates BP via oxidative stress.

Tryptophan Metabolism: From Amino Acid to Vascular Protection

Tryptophan, an essential amino acid, follows the kynurenine pathway, yielding tetrahydrobiopterin (BH4)—a nitric oxide synthase cofactor promoting vasodilation. CHH increased BH4, mediating 16.9% SBP drop. Mechanism: 1) Tryptophan hydroxylase/indoleamine 2,3-dioxygenase converts to intermediates; 2) BH4 synthesis via pterin pathway; 3) BH4 recouples eNOS, boosting NO for vessel relaxation; 4) Diet's plant proteins supply tryptophan, countering hypertension-linked deficits.

Three metabolites here amplified DBP benefits (27.7%). Dysregulated tryptophan catabolism fuels inflammation; CHH restores balance.

Sun Yat-sen University's Pivotal Role in Nutrition Science

SYSU's School of Public Health, with labs like Guangdong Provincial Key Laboratory of Food, Nutrition and Health, drives impactful research. Professor Zhu Huilian, PhD in Toxicology, MD, MS in Nutrition, has published on diet-chronic disease links, including betaine's anti-hypertensive potential. Co-first authors Jiedong Chen (PhD candidate) and Si Chen (postdoc) exemplify emerging talent. SYSU ranks high globally (top 85 US News), fostering trials like DECIDE-Diet amid China's HE push for translational research.

This work positions SYSU as a leader in metabolomics-nutrition interface, inspiring collaborations.

Implications for Public Health and Policy in China

With hypertension causing 2.5 million annual deaths, CHH offers scalable, affordable intervention—cost-effective per prior data. Pathways suggest targets for supplements or fortified foods. Policymakers can integrate into national guidelines, echoing 'Healthy China 2030'.

Future Outlook: From Bench to Global Table

Ongoing trials test long-term effects; precision via genotyping could personalize CHH. SYSU eyes gut microbiome links next. Actionable: Adopt CHH principles—halve salt, double veggies—for BP control.

• Consult nutritionists for tailored plans.
• Track via home monitors.

For researchers: Explore acylcarnitine blockers or BH4 boosters.

Photo by DIANA HAUAN on Unsplash

Career Opportunities in Nutrition Research

SYSU's success highlights demand for experts in metabolomics, epidemiology. China invests heavily in HE nutrition labs, offering faculty/postdoc roles.