About 6,000 years ago, our ancestors discovered that salt can preserve food. Today we have better ways of keeping food fresh, but pickled food is still popular among Chinese people. Our taste buds are indulged by the modern food industry so much that it seems we always need one more dainty, a little more salt. But addiction to salty food is damaging people's health.

Studies have found it is closely linked to many diseases. Researchers have discovered excessive intake of salt raises blood pressure, the main cause of cardiovascular and cerebrovascular diseases. "Each additional gram of salt consumed per day was associated with 0.4 millimeters of mercury higher systolic blood pressure," said Professor Bruce Neal, professor of Medicine at the University of Sydney at a chronic disease prevention forum hosted by the George Institute for Global Health at Peking University earlier this month.

He said reducing salt intake by 3 grams a day will lower the risk of a stroke by 15 percent and coronary heart disease by 9 percent. And the effect will increase over time.

For most countries, average salt consumption is five to 10 times higher than the 1 g per day we are designed for, Neal said. On average Chinese people eat 12 to 14 g per day. The World Health Organization set the international maximum salt intake at 5 g a day for adults in 2002. The hypertension population in China amounts to 160 million. According to statistics from the Chinese Medical Association, 3 million stroke deaths were reported in 2009 in China, more than twice that of 1985.

"If the average intake of salt each day can be reduced to 5 to 6 g per day in China, about 360,000 stroke and heart deaths can be prevented a year," Graham A MacGregor, professor of Cardiovascular Medicine, London-based Wolfson Institute of Preventive Medicine, said at the forum.

He called for an urgent national campaign to reduce salt intake. He suggests different approaches should be taken for rural and urban residents. The main source of salt for Chinese farmers is the salt they add to their food in cooking. In contrast, urban dwellers eat more processed food and they eat out more often than their counterparts in the countryside.

Most consumers have no idea of the hidden salt in foods. Actually bacon and smoked fish are twice as salty as sea-water. As a common condiment in Northern China, 100 g soy sauce contains almost 20 g salt.

Campaigns for less intake of salt have already been staged in some European countries for half a century. Pakistan, Bangladesh, Nepal, Kenya, Ghana and some Latin American countries are all actively considering how to reduce salt intake. The salt reducing campaign in the UK showed every one pound spent reducing salt intake saved 300 pounds of medical care expenses treating salt-related chronic conditions.

He believes that the government, media and the food industry should all be involved in the campaign. The government should be responsible for coordinating and organizing the media publicity to keep people informed of the risks of excessive salt intake. And it is also government's duty to pass strict laws to force the food industry to reduce salt in their products.

Wu Yangfeng, director of The George Institute for Global Health, said the Beijing municipal government has already initiated its campaign. Substitute salt is available in more and more villages. Low sodium salt takes the most visible position on the shelf of the supermarkets in Beijing now.

Lei Zhenglong, director of Division of Chronic Disease Prevention and Control of Ministry of Health, said the central government has realized the importance of low salt diet as a public health issue, and it will be covered by the new round of health reform with special funds.