Study identifies a new community-based strategy to reduce population sodium intake in rural China

A community-based sodium reduction intervention program has achieved significant reduction in sodium intake among rural residents in northern China.

The study findings, according to researchers at The George Institute for Global Health, will positively impact  public health policy making in China and have broader applicability  to other similar settings around the world.

Salt added during cooking is the main source of sodium intake in northern rural area of China. Excess sodium intake is a key determinant of high blood pressure, the leading cause of stroke, a chronic disease which is responsible for about 1.7 million deaths each year in China. The average sodium intake in northern China is 4.7g-5.9g sodium per day, which is far in excess of the current recommendation from World Health Organization (WHO) for maximum daily sodium intake—2g/day, and exposes the residents to higher risk of having stroke and other vascular diseases.

“Centrally implemented, population-based approaches to salt reduction have been identified by the WHO and other groups as amongst the most cost-effective possible strategies for vascular disease prevention in both developed and developing countries,” said Dr Nicole Li, Research Fellow at The George Institute for Global Health, Australia. “We identified a low-cost, highly practical intervention that was effective in reducing population sodium intake.”

This study is one of the two interventions conducted by the China Rural Health Initiative (CRHI), the flagship project representing an excellent collaboration between The George Institute for Global Health and other 11 international and local academic institutions as well as the China National Health and Family Planning Commission and local governments in Hebei, Liaoning, Shanxi and Shaanxi provinces and the Ningxia Autonomous Region.

The study was active in 120 rural villages from five northern provinces of China over 18 months. 60 villages were randomized to receive no intervention and continued with their usual practices. The remaining 60 villages received community-based health education advising lower sodium intake, with special messages for residents at high risk of cardiovascular disease. In addition, a low-sodium salt substitute was promoted through health education program and in village convenience stores. These 60 villages were further divided at random with 30 receiving a price subsidy for the salt substitute, and 30 getting the substitute at full price, which is about twice that of regular salt.

24-hour urine samples of 20 people from each village for sodium and potassium intake were examined after the intervention, the outcome of which was positive and inspiring:

• Reduced daily sodium intake by 13 mmol (millimoles, 17 mmol equals about 1 gram of salt) compared with non-intervention villages; Reduced daily sodium by 17 mmol in villages with price-subsidized salt substitutes.
• Increased daily potassium intake by 7 mmol on average across all villages with the intervention; Increased daily potassium intake by 9 mmol in villages with price-subsidized salt substitutes.

Professor Yangfeng WU, director of The George Institute for Global Health at Peking University Health Science Center, indicated that the study findings will certainly be relevant to public health policy making in the future. “Population sodium intake was effectively reduced by our intervention, primarily through increased use of salt substitute. It also suggests how the community can be engaged in tackling and ‘owning’ a major health issue. Larger effects could be achieved in rural China by a wholesale switch from salt to salt substitute, with the potential for major public health benefit in this population at high risk of stroke. ”

The research findings were presented at the American Heart Association Conference on November 18, 2013.

Research reported in this publication was supported by the US National Heart, Lung and Blood Institute (NIH) and US Centers for Disease Control and Prevention, Center for Global Health and National Center for Chronic Disease and Prevention (Contract HHSN268200900027C), and the UnitedHealth Group Chronic Disease Initiative.