Lack of minerals in Hongkongers' diets 'could lead to health problems'

Researchers warn of health problems as mineral consumption fails to match recommended levels

PUBLISHED : Wednesday, 10 December, 2014, 6:31pm
UPDATED : Thursday, 11 December, 2014, 7:46am

Hongkongers consume too much sodium and don't get enough calcium, iron or potassium in their diets, according to the first study of the local population's mineral intake - and doctors are warning the deficit could lead to health problems in the future.

The Centre for Food Safety report is the ninth and last in a series that makes up the "First Hong Kong Total Diet Study", launched in March 2010.

All nine studies are based on food consumption data, collected between 2005 and 2007 from 5,008 adults aged 20 to 84.

From March 2010 to February 2011 the centre examined 600 composite samples of 150 food items to identify the consumption of 13 minerals in adults.

The research revealed that more than 90 per cent of adults did not meet the recommended intake for calcium, which is important for the skeleton and metabolic processes. While the World Health Organisation recommends at least 1 gram per day, the average consumption was just 430mg. Even high consumers, who made up the top 5 per cent of those surveyed, had a daily intake of just 840mg.

"Inadequate intake of calcium leads to the risk of osteoporosis in the general adult population," said Dr Samuel Yeung Tze-kiu, principal medical officer of the centre.

The optimal bone mass is maintained in young adulthood. From around 40, loss of bone mass becomes more obvious.

More than 80 per cent of adults did not consume enough iron, which can lead to anaemia and reduced immune function.

Young women and pregnant women are at risk of iron deficiency as they have a higher requirement of iron. In contrast to the daily intake of 12mg recommended by the Chinese Nutrition Society, the average consumption for adults was 8mg.

While 60 per cent of the general adult population had a deficit in potassium, which is essential in maintaining the electrolyte balance, the same percentage also exceeded the amount of sodium recommended.

Inadequate intake of iron and excessive amount of sodium would lead to greater chances of high blood pressure, which might increase the possibility of stroke and coronary heart disease, Yeung said.

Yeung advised adults to eat more food rich in minerals, such as dairy products, beans and dark green vegetables. Use of salts and sauces should be reduced during cooking, he added.

"When eating out, you have the right to choose your own food ... ask for less salty and greasy dishes," Yeung said.

Jacqueline Fung Wai-chung, scientific officer at the centre, said two glasses of milk a day could provide enough calcium and two bowls of cooked vegetables or three bowls of raw ones should give adequate daily amounts of iron.

"The public are advised to eat a diverse range of food and consider the food pyramid," said Yeung. A food pyramid is a nutritional diagram in the shape of a pyramid, representing the optimal number of servings to be eaten each day from each of the basic food groups.