While in recent weeks there have been controversy over whether benzoic acid in soft drinks causes health challenges, a scientist and Chairman, Nigerian Beverages Panel, Prof. Babatunde Oguntona, in this interview with select journalists explains why the preservative is used in foods and drinks. He said the benzene produced from benzoic acid is insignificant to cause health risk, but stressed on the intake of soft drinks in moderation. Martins Ifijeh brings excerpts
What is benzoic acid and why is it recently of concern?
Benzoic acid is a very well known preservative in the food industry and it has been in use for a very long time. It is used not only in beverages but in other processed foods. It is generally regarded as safe. So that brings us to the benefits and the risks. Benefits include the fact that it is a very good antimicrobial agent.
Ordinarily it should not be a problem but a few years ago, there was a research carried out in the United Kingdom that indicated that in the presence of vitamin C, this particular substance can be converted to benzene, which is carcinogenic. So people were alerted to the danger.
When you have a situation whereby it comes in contact with vitamin C, there is the likelihood of production of benzene which is carcinogenic.
Why is benzoic acids used in foods and drinks?
Benzoic acid is a preservative. It is one of the tools used to ensure food security. It helps us to have a regular supply of foods and drinks. Because if we do not preserve the food or drink, it will be difficult to maintain steady supply.
Statistics have shown that more than 50 per cent of fruits produced in Nigeria are wasted. Imagine if we can prevent that? These chemicals help us to achieve that. They also help to keep the foods attractive. Take for instance, an orange flavoured soft drink – it sends a message to your brain that you are taking orange. That is why colourings are added.
The alternative is to eat contaminated foods but with preservatives, that will be avoided. Benzoic acid is used in processed foods and it stops microbes from growing. It prevents infection and is cheaply produced. Manufacturers love it.
But how will benzoic acid lead to benzene which is carcinogenic?
One of the conditions that affects rate or amount of production of benzene is high temperature, the other is ultraviolet radiation. When you have a combination of these two, the rate of production of benzene is increased and you know these conditions are applicable here because we have very high temperature and also because of sunlight, we have ultra violent radiation. Other conditions that do not support the rapid production of benzene include presence of sugar.
You have the conditions that promote production of benzene in the environment, and you also have the conditions that do not promote and limit the production of benzene in the same product because, there is sugar in the sweeteners used in beverages.
So how does this add up?
Scientifically, the temperature required is in the region of 60 degrees Celsius. I don’t know anywhere in this country where the temperature can get up to 80 degrees Celsius. I cannot recall anytime we have recorded up to 60 degrees. We can say that the 60 per cent option cannot really be applicable but for the ultraviolet rays, there is possibility especially when you put the product in the sun. If you expose the products to the sun you will promote conditions for its production. If the product is exposed to the sun for two hours or more, benzene is likely to be produced.
At what level can benzene be produced in soft drinks?
We have agreed that benzene is carcinogenic. We have also agreed that given certain conditions, like heat and sunlight, it can be produced from benzoic acid but at what level this happens, I can’t tell.
I don’t have the information for Nigeria and I don’t know if anyone has. This is the type of information NAFDAC, Ministry of Health and Standards Organisation of Nigeria, should be collating.
In fact, it should guide them in determining what level of benzoic acid to be given to manufacturers. In other countries, there have been experiments to determine the levels of benzoic preservatives. Put them in three categories. There are countries that are technologically developed, like Sweden, or Austria,where they consume a lot of processed foods and beverages.
The second group is the developing countries such as Nigeria, Brazil and Malaysia where less than 50 per cent of their daily food come from processed foods and they don’t consume a lot of beverages.
The third group is the one in-between – countries that are not quite developed but are more developed than the second group. We have information that representatives of these groups have done a survey and found out that the amount of benzene produced in beverages in the world is sometimes not detectable or very minimal.
They found out that the amount produced in the top of the bottle space between the liquid and the cork is too small to be of a health concern. I am not saying that benzene is not produced but the question is how much is produced. It is insignificant to cause a health problem.
If somebody comes out tomorrow in Nigeria and does his survey, we will quote his figure. It is very easy to be emotional when it concerns a big company but we are not helping our people if we are not providing them the right information.
What about the minimum energy and protein levels?
Again, scientifically, take a broader look at the issue of beverage consumption from perspective of food security in the country. We have important statistics collated in Nigeria in the context of food security.
We say Nigerians are not well fed and don’t meet the minimum energy and protein levels and from the data, we have suggested that beverages as a group contribute between 19 per cent to 49 per cent energy intake of Nigerians. That is a lot. In other words, for groups like labourers, it contributes over 50 per cent. If you remove that, what will you replace it with? That is another deficit in the food balance sheet.
I am not saying you should go ahead and take soft drinks or that you should not take soft drinks. I do not work for any soft drink manufacturer but I am for the interest of Nigerians.
I am basing my thoughts on pure science. People can base their choices on science. Wherever they have done these surveys, they have found that the production of this chemical is negligible.
People say taking soft drinks with drugs or vitamin C is dangerous. How true is this?
Don’t take your drugs with soft drinks, take it with water instead. It is not that you cannot take vitamin C, rather, the message is that you do not take it with soft drink because it reacts with the benzoic acid in the soft drink.
The advice from Federal Ministry of Health is to take medicines with water. You can have soft drinks later. The function of food is different from the function of medicines. Beverages come under the classification of food and drinks while medicine is different thing entirely. After all, you take injection and nobody adds soft drink to it. The reason why you add water is to allow it to rapidly enter your system. The message is separate drugs from soft drinks. The negative impact on those who don’t separate depends on the drugs. I got a phone call now from somebody from Ekiti, he says they take drugs with palm wine. Until we do the survey or somebody does it, I cannot say is this or not because I am a scientist.
Does benzoic acid affects shelf life of foods and beverages?
Benzoic acid does not determine shelf life of a product. This is debatable. Shelf life depends on the preservative used, the products and storage environment. Besides, those variables can change at any time.
No one knows at what level these preservatives become injurious to health. The question is what is the minimal level? No one can answer that question. Even the international agencies use standard for pure water that should not be so. The concern is that no matter what amount of benzoic acid you put, once it is in contact with vitamin C, it will react, it is a chemical reaction. No matter the level.
We don’t have information about how much benzene is produced. Countries that have that information say is at a negligible level. The available data on dietary exposure to benzene is minimal from the viewpoint of public health. Often benzene levels were low as to be considered negligible and not a consumer health risk, but there is still a need for more studies for a better understanding of their effects on human health through the ingestion of contaminated food. In a study by Centre Food Safety and Applied Nutrition, and U.S. Food and Drug Admninistration, it was found that the amount of benzene found in the reformulated beverages ranged from none detected to 1.1 ng/g.
So what is the take home message in this?
The rule is moderation. It is like water, if you sit at a place and continue to take more than six bottles of water within an hour, at the end of the day, you will drown. That is ordinary water. Moderation is the key word. One of the surveys we have done is on limited consumption of beverages to average of two to threebottles per day. It shouldn’t be more than two or three bottles daily.
Are there warnings on products for this?
There is tendency that people may not read it. What is important is grassroots education. The Federal Ministry of Information and Culture and Ministry of Health should move into the local governments to check these things. NAFDAC should educate Nigerians. It is education we need not warnings. There should be bill boards to educate Nigerians. Nigerians are not good at reading the labels on the products. Manufacturers are there to make money. If you allow them they will not do anything. But the ministries have the responsibility to educate Nigerians on the dangers of some of these things.