Results of study on aluminium in food

The Centre for Food Safety (CFS) today (May 20) released results of a study which examined the aluminium levels in foods, and which aimed to estimate the dietary exposure to aluminium of the population and to assess its associated health risks.

The Centre's Consultant (Community Medicine) (Risk Assessment and Communication), Dr Ho Yuk-yin, said that 256 samples, comprising 60 prepackaged and 196 non-prepackaged food samples, were taken from the local market for testing of aluminium.

They covered seven groups of food products in which aluminium-containing food additives might have been used. These included steamed bread, buns and cakes; bakery products; ready-to-eat jellyfish; confectionery with coating; snacks including fried snack products; other food products, such as pickles, mung bean vermicelli and cheese products; and powder mixes, salt and sugar.

Aluminium was detected in most samples: steamed bread, buns and cakes (mean: 100-320mg/kg); some bakery products, such as muffins (mean: 250mg/kg), pancakes and waffles (mean: 160mg/kg), coconut tarts (mean: 120mg/kg) and cakes (mean: 91mg/kg); and ready-to-eat jellyfish (mean: 1,200mg/kg).

"Aluminium can be present in food for various reasons, such as the use of aluminium-containing food additives as raising agent, firming agent, anti-caking agent and colouring matter. Aluminium may also exist in food naturally, but normally at low levels. And the main dietary source of the general population would be food with aluminium-containing food additives added," Dr Ho said.

Aluminium has the potential to affect the reproductive and developing nervous system in experimental animals. In 2006, the Joint Food and Agriculture Organisation of the United Nations/World Health Organisation Expert Committee on Food Additives (JECFA) lowered the safety reference value for aluminium, the Provisional Tolerable Weekly Intake (PTWI), from seven mg/kg body weight (bw) to one mg/kg bw.

Dr Ho said that in assessing the associated health risks based on the current study, the CFS had used the average consumption data of food groups and the corresponding average aluminium concentrations for estimating the dietary exposure.

The average dietary exposure to aluminium of a 60-kg adult was estimated to be 0.6mg/kg bw/week, about 60% of the PTWI established by JECFA. Steamed bread, buns and cakes were the largest contributors to the total dietary exposure to aluminium (average dietary exposure: 0.36mg/kg bw/week), accounting for about 60% of the total exposure.

"Based on these assessments, aluminium exposure through normal food consumption should not pose any undesirable health effects. But for those who regularly consume foods added with aluminium-containing food additives, adverse health effects cannot be ruled out," he said.

Dr Ho urged the food trade to reduce the use of aluminium-containing food additives in preparing food, replace them with alternatives as far as possible or develop alternative techniques in food processing. The CFS has formed a working group with members of the trade to devise a set of guidelines on the use of aluminium-containing food additives.

"Information on food labels, including specific food additives used, should be given accurately. Members of the public are advised to maintain a balanced diet to avoid excessive exposure to aluminium from a small range of food," he said.

Ends/Wednesday, May 20, 2009