In adults with mild hypertension, a Chinese cuisine-based, heart-healthy diet that reduced sodium intake by half significantly reduced systolic and diastolic BP compared with traditional Chinese diets, researchers reported.
More than one-fifth of the world’s population consumes Chinese cuisines regularly, but no evidence-based healthy diets fitting the Chinese food culture are available for implementation, Yangfeng Wu, MD, PhD, professor of epidemiology and sciences in clinical research at Peking University Clinical Research Institute in Beijing, and colleagues wrote in Circulation.
“The most important message is that healthy diet could be very effective and able to bring about sizable reduction in blood pressure among patients with hypertension, which will ultimately reduce cardiovascular risk,” Wu told Healio. “The key is to reduce sodium intake and fat intake but increase the intake of carbohydrates, protein, fiber and potassium. That can be achieved by reducing use of regular salt, edible oil and red meat; and increasing eating whole grains, low-fat dairies, fruits and vegetables, nuts and beans, and replacing the reduced regular salt with salt substitute.”
For the randomized, double-blind DECIDE-Diet trial, Wu and colleagues analyzed data from 265 participants with a baseline systolic BP between 130 mm Hg and 159 mm Hg from four study centers across China representing four major Chinese cuisines: Shandong, Huaiyang, Cantonese and Sichuan. The mean age of participants was 57 years; 52% were women and mean systolic and diastolic BP were 139.4 mm Hg and 88.1 mm Hg, respectively. Each center chose a collaborative local catering organization to provide a kitchen to run the study; chefs were selected from the catering organizations, trained and overseen by the research staff.
Chinese heart-healthy diet design
The Chinese heart-healthy diet encompasses four versions of Chinese cuisines, with each version including a set of menus for breakfast, lunch and dinner with nonrepetitive dishes within a cycle of at least 2 weeks. Study nutritionists, dietitians and chefs in the study team jointly developed the recipes in advance according to the Chinese heart-healthy diet daily nutrients and energy composition targets, considering the availability and interchangeability of foods during the season. The diet was created to reduce sodium intake by half, from nearly 6,000 mg daily to about 3,000 mg daily, and reduced fat, increase protein and carbohydrates and included twice as much dietary fiber and potassium.
“The daily nutrients and energy composition targets of the Chinese heart healthy diet was based on the Chinese Dietary Guidelines, knowledge obtained from previous successful healthy diets, particularly the Dietary Approaches to Stop Hypertension (DASH) diet, Chinese food and nutrient intake levels from the recent national nutrition survey, and the most common local foods and dishes from our surveys,” the researchers wrote. “Compared with the nutrient composition of a usual Chinese diet in urban China, the Chinese heart-healthy diet had reduced energy from fat by 5% to 8%, increased energy intake from protein by 3.5% to 5.5%, and increased energy from carbohydrates by 0 to 5%, respectively.”
Assessing the intervention
After a 7-day run-in period on a control diet matching the usual local diets, researchers assigned participants to continue with their respective control diet (n = 130) or the cuisine-based Chinese heart-healthy diet (n = 135) for another 28 days. All participants were asked to consume the study meals at breakfast, lunch and dinner; no other intervention was provided to the participants in both groups. Primary outcome was systolic BP; secondary outcomes included diastolic BP and food preference score. Researchers also calculated the incremental cost per 1 mm Hg reduction in systolic BP.
Mean changes in systolic BP from baseline to the end of the intervention were –15 mm Hg (95% CI, –16.5 to –13.5) for the Chinese heart-healthy diet and –5 mm Hg (95% CI, –6.5 to –3.5) for the control diet, for a net difference in the change of systolic BP of –10 mm Hg (95% CI, –12.1 to –7.9) compared with the control diet group (P < .001).
For diastolic BP, mean changes were –6.7 mm Hg (95% CI, –7.5 to –5.7) for the Chinese heart-healthy diet and –2.8 mm Hg (95% CI, –3.7 to –1.9) for the control diet, for a net difference of –3.8 mm Hg (95% CI, –5 to –2.5) compared with the control diet group.
In subgroup analysis, women experienced a greater reduction in systolic BP compared with me (–12 mm Hg vs. –7.6 mm Hg; P for interaction = .037).
The mean food preference score was 9.5 (with 10 the best preferred) at baseline and the net change during intervention was 0.1 (P = .558). The incremental cost effectiveness ratio per 1 mm Hg reduction in systolic BP was 60 cents per day, according to researchers.
“Our findings have strong clinical implications,” Wu told Healio. “The large effect size on blood pressure implies that for patients with mild hypertension, their BP can be brought under control by adopting the Chinese heart-healthy diet alone. Thus, doctors should consider the Chinese heart-healthy diet in the clinical management of all hypertension patients, and they may use the Chinese heart-healthy diet as the only first-line treatment for patients with mild hypertension.”
The researchers noted that the study did not reach the planned recruitment target because of the COVID-19 pandemic and a strict quarantine policy in China.
“Although the sample size was adequate statistically in detecting the main intervention effect, the study may not have sufficient power to detect the effect of cuisine type on the effect,” the researchers wrote.
Wu said implementation research is needed to better understand how the Chinese heart-healthy diet can be prescribed widely.
“Research on the biomedical mechanisms should help in developing new strategies for hypertension treatment,” Wu said.
A diet that includes switching to a salt substitute has been previously shown to be effective. As Healio previously reported, adults in rural China with a history of stroke who switched from regular salt to a salt substitute had a 14% lower rate of stroke and a 13% lower rate of major adverse CV events during a mean 4.74 years of follow-up.