Many people love carbonated soft drinks, but there are concerns about the safety of soft drink consumption.
1) Brominated Vegetable Oils
Few days ago Taiwan Food & Drug Administration ordered a vendor to remove about 15,500 cans of soft drinks with prohibited brominated vegetable oils (BVO) from shelves. Animal studies indicated that high doses of BVO could cause degenerative cardiac lesions in experimental animals, and lead to accumulation of bromine in their adipose tissues.
Image Source：Public Television Service, 2015
At present, BVO is not a permitted food additive in many places (including Taiwan, Hong Kong, Mainland China, European Union, Australia, New Zealand, Singapore and Japan). However, the United States and Canada still allow limited use of BVO in certain fruit-flavoured beverages – 15 ppm in maximum, and a product label indicating the presence of BVO is required. The problematic soft drinks sold in Taiwan were actually exported from United States. However, the translated product label in Chinese just showed “corn oil”, rather than BVO.
In 2009, the media reported that some soft drinks sold in the Brazilian market were found to contain benzene. Theoretically speaking, benzene could be formed if soft drinks contain both benzoic acid or its salts (as preservative) and vitamin C (as antioxidant), and in the presence of light and elevated temperatures or under a favourable condition (e.g. pH).
However, consumers need not to be too worried because previous studies indicated that beverages in several countries generally contained benzene at a level lower than the World Health Organization (WHO) guideline value of 10 mg/L of benzene established for drinking water. It should be noted that exposure to low levels of benzene from soft drinks does not raise any health concerns.
Last year cola drinks manufactured in United States were reported to contain 4-methylimidazole (4-MEI) which is “possibly carcinogenic to humans”. This is because caramel colours commonly used cola drinks might form 4-MEI as a by-product under certain temperature and pressure.
Since the levels of 4-MEI previously found in cola drinks were low, food safety authorities in different countries (including United States and European Union) generally agree that exposure to 4-MEI via consumption of foods containing caramel colors will not lead to adverse health consequences. For example, if a bottle of 12 fl. oz. cola drinks contains 353.5 micrograms of 4-MEI, a consumer would have to consume over 130 bottles of cola drinks daily to reach the doses causing cancers in rodents.
Many peoples should already know sugar content of carbonated soft drinks is high, which will increase the risk of overweight, obesity and dental caries. That’s why the Centre for Food Safety (CFS) of HKSAR Government often advises the public to eat healthier by avoiding food and drinks with excessive sugar (e.g. sugar free soft drinks instead). In Hong Kong under the Food and Drugs (Composition and Labelling) Regulations (Cap. 132W), prepackaged food with “low sugars” or “no sugars” claim must contain no more than 5 grams or 0.5 grams of sugars respectively per 100 grams of solid / liquid food.
5) Bisphenol A
In the past, there was also a concern over trace amount of bisphenol A (BPA) present in the protective coating of cola cans, which might contaminate the drinks inside. Although studies showed that BPA has adverse effects on nervous system, behaviour during the developmental period and on reproductive system, different countries generally consider that the amount of BPA absorbed from food and drinks is very low, and unlikely pose a health risk.
6) Small Glass Fragments
Apart from chemical substances, foreign substances such small glass fragments may also be found in soft drinks during production. In August 2015, CFS urged the public not to consume five kinds of bottled soft drinks imported from New Zealand as they might contain small glass particles; and the trade should stop selling the products concerned.
Just like other foods, carbonated soft drinks might also become unsatisfactory if preservatives, heavy metals and microbes exceed the regulatory or tolerance levels.