Is safe food a matter of chance?

Everyone wants to eat food that is absolutely safe, but among all human activities, the one that is quite risky is eating food. Food can become unsafe right from the farm till the plate. It is essential that we know what the hazards are at every stage and for every food and how to avoid or minimize them. This is a procedure called risk assessment and risk management. The hazards, e.g., contaminants, would either be eliminated completely, which is most often impossible, or a permissible level will be determined based on toxicological assessments.

One may wonder why there should be a permissible limit at all for a contaminant or an unsafe ingredient. Practically speaking, it is nearly impossible for all contaminants to be zero in food. We should also understand that the human race has evolved in an environment full of contaminants and hazards and we got genetically empowered to handle a certain limit of many such hazards. Acceptable limits are based on lab animal data. Animals that are fed these contaminants may develop an adverse effect at some dose.

The ‘lowest observed adverse effect level’ is abbreviated as LOAEL. One dose below that is called the ‘no observed adverse effect level’ or NOAEL. A hundredth of that dose is generally considered safe for humans. Human data are also used when accidental exposure or adverse events are documented. Hence, there would always be an acceptable limit.

Since the same contaminant can be found in different types of food which we may consume on the same day, the acceptable limit is the sum total of a single contaminant from all these foods put together. Another aspect to consider while fixing limits is the overall benefit of consuming such foods despite the contaminant, for example, pesticide residues. Without the use of pesticides, there will be huge food losses that we need to avoid in order to have sufficient affordable food to feed the population. (One can’t obviously feed the population with organic food). Similarly, if we do not use preservatives, food spoilage would result in a shorter shelf life and food wastage.

Toxicity or harm due to a substance is a matter of dosage. Most substances that could be contaminants or additives or preservatives will be beneficial at some levels and harmful at the other extreme of intake. It is traditional knowledge that even nectar will be poison beyond a limit and poison could be a panacea in very small quantities.

If we consider pesticides as an example, there are permissible limits for pesticides in various foods, maximum residue limits and acceptable daily intakes. With good agricultural practices and after an adequate storage time, very small amounts of pesticides should remain. Similarly, several other crops where the same pesticide is used would also contain small amounts of the same pesticide. Collectively, the maximum intake from all sources will be measured and this should be below that acceptable daily intake level which, in turn, will be around one hundredth of a level where adverse events were seen. Toxicologists also take into account the long-term effects of accumulation of the toxin in the body and also the interaction and additive effects of different kinds of pesticides.

A lot of effort goes into the approval of anything that is added to food or can contaminate food. Organic foods claim that they are at zero level, but should be verified by the regulator and certified so.

However, for bacteria and other pathogens, the tolerance is very little or near zero, since even a few organisms can cause serious infections. Similarly, allergens can be risky for those who are allergic to that particular food. Food regulation expects the manufacturer to ensure that contaminants, additives, artificial substances etc. are all within these permissible or safe limits. The regulator frequently samples foods from the market and analyses to see the extent of compliance. In many countries, voluntary withdrawal of food from the market is encouraged whenever the manufacturing company itself feels there is something unsafe in the food supplied to the market.

While inadvertent presence of an unsafe substance in an unsafe level is pardonable, deliberate addition—adulteration—is punishable and a crime. Our markets have quite a bit of unregulated food operators. Milk and oil are two major commodities which could be adulterated. We should be worrying more about these and a lot of foods being prepared in restaurants and on the streets. One should obtain food from reliable sources who follow safe practices and hygiene. An overarching food regulation, which takes care of every food that we eat, is impossible. They do not have the kind of manpower nor the testing facilities or mechanisms to take punitive action. Stringent punishment for violators and unambiguous standards with meaningful science-based product approvals and monitoring are the need of the hour.

Until then, good luck!

B. Sesikeran is chairman, scientific panel on labelling, at the Food Safety and Standards Authority of India.