Does your soy sauce cause cancer?

Last week, Miss Pinky Webb of ABS-CBN presented a report that many of the popular soy sauce brands in the market could be cancer causing. Considering how much soy sauce is part of the Filipino diet  the news report should have caused a mega stir but surprisingly it did not.

It could be that folks just took the soy sauce report with a grain of salt after the airing of so many questionable news reports by the broadcast media, which are slanted towards perpetuating the Filipino over-entertained and under informed syndrome. It could also be that Filipinos  besieged by high prices, lawlessness in our communities, terrorist threats, an alarming Metro Manila pollution, rampant infections  simply considered the cancer risk in some soy sauce brands as less likely to kill them.

Whatever it is, your Chair Wrecker felt that the matter needed a deeper probe. The ABS-CBN report avoided specifying the soy sauce brands that contain the risk of cancer. Luckily, we have the right friend to call on for this clarification - Dr. Suzette Lazo, the Director of the FDA (Food and Drug Administration).

During our phone discussion, Dr. Suzette narrated how this had already been raised as an issue several years ago and that they had already looked into it and had taken the necessary steps to ensure consumer protection. Dr. Suzette was surprised why this issue was resurrected since the warning did not come from the FDA. Further investigation by your Chair Wrecker pointed to a market player as the source of the scare campaign.

Per Dr. Suzette, the substance in question is called 3-MCPD  a by-product of acid hydrolysis of a vegetable protein called HVP. Dr. Suzette also shared with us a primer, transmitted via email, she had made about this issue, as follows:

Primer on 3-MCPD

1. 3 chloro-1,2-propanediol (3-MCPD) is a by-product of acid hydrolysis process of vegetable protein (HVP) shown by animal studies to be carcinogenic at high doses (greater than 20 ppm) when given at prolonged periods in animals (Sunahara 1993, Cho 2008 - Appendix 1). The carcinogenic effect is through a non-genotoxic mechanism (in October 2000 the Committee on Mutagenicity of Chemicals in Food, Consumer Products and the Environment considered two new toxicity studies and has advised that 3-MCPD need no longer be considered as mutagenic in vivo, but still carcinogenic in animals.

2. Given the demonstrated carcinogenic effect, there has been no such effect actually documented in human subjects. JECFA states: “At any level of intake that can reasonably be expected to be encountered, 3-chloro-1,2-propanediol would not show acute toxic effects...” (page 21 , WHO Food Additives Series 48).

3. Initial levels surveyed in Asian soya sauces (soy sauce, oyster sauce) showed excessively high levels of 3-MCPD (about 300 ppm) but over the years, improvement in production have decreased these levels and previously non-compliant products have met the standards.

4. Around 2001, countries set standards for allowable limits of 3-MCPD based on results of toxicity studies. Health Canada for example used the LOEFL value of 1.1 mg/kg body weight per day demonstrated by long-term toxicity and carcinogenicity effects from the Sunahara study in 1993 and applying an UNCERTAINTY FACTOR of 1000 as follows: 1.1 mg divided by a factor of 1000 = 1.1 ug/kg as the Tolerable Daily Intake (TDI).

5. In 2002, the Bureau of Food and Drug issued Memorandum Circular No. 4 (Appendix 3) adopting 1 ppm as the allowable limits of 3-MCPD contaminant in soy sauce products following the standards used by the US FDA, Health Canada and Thailand.

6. Over the years, further studies have been carried out in Asian populations to ascertain the risk from consumption of 3-MCPD. Studies have been conducted in Asia  in Hong Kong and in Thailand that showed that based on actual consumption, subjects in the study were unlikely to experience major toxicological effects from 3- MCPD (Appendix 4).

7. Downstream of the 3-MCPD metabolic pathway is another chloropro-panol, 1,3 DCP which has also been shown to be carcinogenic.

8. Later surveys in Europe have ascertained that aside from soy sauce products, 3-MCPD is present in a wide range of foods that includes cereals (biscuits, including malted and toasted products), bread, breakfast cereals, corn snacks, savoury crackers. Dairy creams (aerosols and dessert toppings); low fat cheeses, Parmesan cheeses, processed cheeses and cheese alternatives, meats (chargrilled burgers, cooked meat, salami, smoked bacon, breaded products, cakes and pastries). In light of these findings, there is a call to reduce the levels of chloropropanols as low as technologically possible and the public is advised to maintain a balanced diet in order to avoid excessive intake of 3-MCPD and 1,3-DCP. The European Union has adopted a lower standard that allows 0.02 mg/kg of 3-MCPD in soy sauce, which came into force in 2002. The Codex Alimentarius adopted a higher standard of 0.4 mg/kg, which the FDA will also be adopting next year.

9. FDA has made a general review of all soy sauce products in the Philippines and to date 16 products have been compliant with the 1-ppm maximum allowable limit (DOH-FDA Advisory 2011-015 in Appendix 5). Products that failed to comply were subjected to voluntary recall until they can demonstrate that 3-MCPD levels comply with standards through improvement of the manufacturing process.

10. FDA assures the public that soy sauce products compliant with the 1-ppm maximum allowable standard are safe for consumption. Acute toxicity studies (LD50) as determined by JECFA of 150 mg/kg will require continuous intake of about 8,000 liters for prolonged periods to cause harm; a volume which is impossible far too much (Appendix 6). Estimations also show that even with daily intake of 30 ml based on consumption data of heavy users like the Japanese would show that users of Philippine soy sauce products would consume amounts of 3-MCPD which is several-fold (23 times) lower that the Tolerable Daily Intake of 3-MCPD (Appendix 7).

Prepared by:

Suzette H. Lazo, MD

Director

Food and Drug Administration

Due to space limitations, the mentioned appendices could not be included.

Filipinos should make it a habit to check the FDA content analysis of each of the food and drink brands that they’re consuming. We should do this as if our lives depended on it. In a globalized world, the risks that many food and drink products could be harmful have increased concomitantly.

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Chair Wrecker e-mail and website: [email protected] and www.chairwrecker.com