Blood pressure levels dropped significantly among Chinese adults with high blood pressure who ate a modified heart-healthy, low-sodium traditional Chinese diet for four weeks, according to new research published today in the American Heart Association’s flagship journal. circulation.
Sodium reduction was a key feature of the Chinese heart-healthy diet designed along the lines of the Dietary Approaches to Stop Hypertension (DASH) diet. An unhealthy diet, especially one high in sodium, is a major modifiable risk factor for high blood pressure.
“Compared to the nutrient composition of a typical Chinese meal in urban China, our heart-healthy diet of traditional Chinese food halved sodium, from 6,000 mg to 3,000 mg daily, reduced fat and doubled dietary fiber, carbohydrates and potassium,” said the research team. First author and co-chair Yanfang Wang, PhD, is a nutritionist and professor research fellow at Peking University Clinical Research Institute in Beijing, China.
According to the survey, Chinese people make up more than one-fifth of the world’s population. As in other parts of the world, the burden of cardiovascular disease has increased rapidly in recent decades in China. Unhealthy changes in Chinese food are a major cause of increased cardiovascular disease.
According to the 2012 China National Nutrition Survey, healthy foods such as grains (34%), tubers and legumes (80%), and vegetables and fruits (15%) have declined significantly. In contrast, meat (162%), eggs (233%), and edible oils (132%) increased dramatically over the same period.
“Chinese people who live in the United States and elsewhere often maintain a traditional Chinese diet, which is very different from a Western diet,” said research team chair Yangfeng Wu, MD, PhD, professor of epidemiology and science. Clinical Research at Peking University Clinical Research Institute, Beijing, China. “Healthy Western diets such as DASH and the Mediterranean have been developed and proven to help lower blood pressure, but, until now, a proven heart-healthy diet has not been developed to match traditional Chinese food.”
The study involved 265 Chinese adults, mean age 56 years, with systolic blood pressure equal to or greater than 130 mm Hg. More than half of the participants were women, and nearly half were taking at least one high blood pressure medication when the study began. Participants were recruited from Beijing, Shanghai, Guangzhou, and Chengdu. These are China’s four major cities, each with a corresponding regional cuisine: Shandong, Huaiyang, Cantonese, and Sichuan, respectively.
The Chinese heart-healthy diet was developed with catering companies in that region and matched with four regional cuisines, so researchers could understand whether the effects of the heart-healthy diet would be applicable and sustainable across different Chinese food cultures. This can sometimes be challenging because traditional Chinese cuisine has a long history of using salt for cooking and preserving food for thousands of years. This was especially true in northern China, where the cold climate lacked green vegetables and people had to eat salt-preserved vegetables during the winter and spring seasons. This is why sodium intake is higher for people living in northern China.
At the beginning of the study, all participants ate their local, normal diet for seven days so that the new eating plans could be customized to taste and smell. The researchers wanted the heart-healthy diet to be as close in taste to the participant’s normal diet as possible, and adjust the amount of nutrients to be heart-healthy. After an initial 7 days of eating their usual diet, 135 of the adults were randomly selected to eat the new Chinese heart-healthy diet for 28 days, and the remaining 130 participants ate from their usual diet. Depending on group assignment, the meals were either regular or heart-healthy versions of Shandong, Huayang, Cantonese, and Szechuan dishes. Study participants and blood pressure assessors were unaware of which dietary group participants were assigned to.
Researchers measured participants’ blood pressure before and after the study and once a week during the study. Food ingredients were weighed for each meal to calculate nutrient content for each meal. Urine samples were collected at the beginning and end of the study to measure sodium and potassium intake. The results indicate that the blood pressure-lowering effect of the Chinese heart-healthy diet is substantial and may be consistent with hypertension medication.
The study found:
- Participants who ate the Chinese heart-healthy diet had lower blood pressure, with systolic (top number) blood pressure dropping an average of 10 mm Hg and diastolic blood pressure dropping an average of 3.8 mm Hg, compared to those who ate the regular diet.
- In the heart-healthy group, calorie intake increased from carbohydrates (8%) and protein (4%) and decreased from fat (11%). Fiber (14 grams), potassium (1,573 mg), magnesium (194 mg) and calcium (413 mg) increased, while sodium decreased (2,836 mg). The nutrient intake of the regular diet group, however, remained almost unchanged from the beginning to the end of the study.
- Taste and flavor preferences of the Chinese heart-healthy diet were comparable to the typical local diet, and participants ate similar amounts of food and scored their diets high in both dietary groups.
- The additional cost of the heart-healthy Chinese diet was about 4 RMB (equivalent to 0.60 USD) per day, on average, compared to the typical local diet. It was considered low and generally affordable.
- Blood pressure-lowering effects were consistent among participants in the four heart-healthy Chinese cuisine groups.
The researchers noted that these findings suggest that if the effects achieved by the heart-healthy Chinese diet are sustained, major cardiovascular disease can be reduced by 20%; heart failure by 28% and all-cause mortality by 13%.
“Health professionals should recommend a heart-healthy diet low in sodium and high in potassium, fiber, vegetables and fruits as first-line treatment for patients with high blood pressure,” Wu said. “Because traditional Chinese dietary culture and cooking methods are often used by Chinese people wherever they live, I believe a heart-healthy Chinese diet and the principles we used to create the diet will also be helpful for Chinese Americans.”
American Heart Association volunteer expert Lawrence J. Appel, MD, MPH, FAHA, noted, “The results of this trial are really impressive and provide a roadmap for healthy eating for people who eat a variety of Chinese cuisines — Shandong, Huayang, Cantonese or Szechuan cuisine. Blood pressure population- Major public health efforts are warranted to ‘scale up’ across China to achieve widespread reduction.”
Apple is vice chair of the American Heart Association’s 2021 Scientific Statement, Writing Group on Dietary Guidelines for Improving Cardiovascular Health. The guidelines recommend eating whole grains, lean and plant-based proteins, and a variety of fruits and vegetables; Limit salt, sugar, animal fat, processed foods and alcohol; And these guidelines apply regardless of where the food is prepared or consumed.
A limitation of the study is that the heart-healthy Chinese diet was tested for only four weeks. A longer study period could confirm and possibly strengthen these findings, according to Wu.
The research was funded by the National Key Research and Development Program of the Ministry of Science and Technology (MOST) of China.