'Silent killer' likely to strike more often due to change in diet, say scientists Hong Kong people are consuming 25 per cent more salt than 16 years ago, making them more prone to high blood pressure, a Chinese University study found. Daily salt intake rose from an average of 8 grams a day in 1989 to 9.9 grams in 2002, said Brian Tomlinson, professor at the university's department of medicine and therapeutics. 'It is a lot of salt. Even 8 grams is quite high but the salt intake going up is a bit of a surprise,' he said. The World Health Organisation recommends adults have an average salt intake of 5 to 6 grams a day - about a teaspoonful - or risk high blood pressure and cardiovascular disease. The researchers had thought that with less preserved food, the dietary salt intake would have naturally declined over the years. The salt content in the urine of 284 healthy people, aged 20 to 65, was measured for the study. Professor Tomlinson said high salt intake is one of the major risk factors for hypertension and one that can be changed easily. Just halving the daily salt intake would lead to a significant reduction of blood pressure in just one month, he said. 'It is just as effective as taking a drug [against hypertension].' Hypertension affects about 18 per cent of the population, and increases with age to 50 per cent in the elderly, said Thomas Chan Yan-keung, professor at the same department. Called the 'silent killer', hypertension usually does not have symptoms. Professor Tomlinson believed that the increasing salt intake among Hong Kong people 'must relate to people's choice of food'. Pre-packaged foods sold in Hong Kong cater for this taste for salty food. 'People choose things that they like. Food manufacturers cater for what the public want. It is a vicious cycle. 'But the problem is that people do not realise that salt is such a serious issue. If they did they would be more careful about choosing food,' he said. He said it would be desirable if Hong Kong placed more importance on food labelling and more attention was paid to the sodium content in processed foods, which account for 75 to 80 per cent of the salt intake. The researchers earlier found that Chinese were particularly susceptible to dietary salt-induced hypertension because they lacked an efficient mechanism to facilitate excretion of salt through urine. The kidneys would normally produce dopamine to lower blood pressure with high salt intake. This mechanism is lacking in Chinese people, Professor Tomlinson said. The professors said they would advise people in their 20s to check their blood pressure every so often. Those in their 30s should have it twice a year, while those over 40 should have it checked every two to three months.