Is your pot safe for cooking?

Part of living healthy is eating healthy. But in this report by SADE OGUNTOLA, experts warn that no pot is perfect for everything and that people also need to be wary of their food being contaminated by chemical substances and heavy metals from their cooking pots.

Are you satisfied that you are doing enough to eat healthy?  Unfortunately, it may not be when you are not selective in your food choices. What about your cookware? Can it be trusted not to be releasing toxic metals like lead, aluminium and other metals into your meals?

It’s a great question because apart from being aware of the pesticides on produce, the mercury in fish and the chemicals generally in food stuffs, the choice of kitchenwares can make a difference too. Some  contain chemicals that can leach into the food.

Aluminium and stainless steel cookwares are the most popular in Nigeria. So what’s wrong with them? Aluminium, although a great heat conductor, lightweight, inexpensive and easy to clean, is a “reactive” metal, and as such it reacts with acidic foods like fruits, tomatoes and leafy vegetables to release itself into the food.

In addition, salty water or food can pit aluminium cookware, making older pots a possible source of trace amounts of substances like arsenic and fluorides.

Contrary to popular belief, stainless steel may not be an inert metal either. All stainless steel has alloys containing nickel, chromium, molybdenum, carbon steel, and other metals that can be released into food in extremely low quantities.

Researchers differ on the health effects of these metals leaching from stainless cookware. Most say that while these quantities are not hazardous to the average person, they may affect those with sensitivities.

For instance, a 1995 study found that stainless steel pans contributed markedly to the levels of nickel in cooked food. In contrast, another study, also released in 1995, found only minor increases in nickel concentrations in acidic foodstuffs when new stainless steel pans were used.

Moreover, Eucharia Onyeka, a Professor of Food Chemistry and Nutrition, Department of Food Science and Technology Federal University of Technology (FUTO), Owerri, in her  inaugural lecture entitled: “Food Security: Concerns and Comforts in Food Processing” also warned that aluminium cooking pots are not good for health reasons.

According to her, “Aluminium is regarded as a macro toxin agent because its salt can be absorbed by the intestine and accumulated in various human tissues including bone, liver, parathyroid and can lead to nutritional disease such as cardiovascular disease, obesity and diabetes”.

In fact, Professor Onyeka said that a pot that contaminates food with itself most was aluminium cooking pots. But if aluminium utensils are coated/anodized, there will be no leaching of the metal during cooking as long as the coating is intact.

She said that developed countries like Germany, France and Great Britain have banned the sale and use of aluminium cookwares and some African countries including Ghana have mandated the use of anodized aluminium cook wares.

“Unfortunately, Nigeria is yet to cue on,  but ignorantly and constantly acquiring to our own health detriment cook wares already rejected by other countries for health reasons,” she declared.

Any fuss about aluminium or steel cooking pots? Actually researchers found all cooking pots leach aluminium, whether new or old.

This was the finding of a comparative study of leaching of Aluminium from old and new aluminium, clay, stainless steel, and steel cooking pots. Rice was cooked in these pots to test the amount of aluminium they released.

The 2013 study involved A. T. Odularu and P. A. Ajibade from the Department of Chemistry, University of Fort Hare, South Africa and Professor Percy Onianwa from the Department of Chemistry, University of Ibadan. It was published in the journal, International Scholarly Research Notices.

The researchers found that although leaching was below and within the control concentration range in all the cooking utensils tested, old aluminium pots had the highest concentration of leached aluminium while new steel pots had the least leaching.

However, the aluminium contaminant of the rice tested, they stated, was insufficient to constitute a hazard to health.

Nevertheless, the fact still remains that once aluminium exceeds the acceptable limit from daily ingestion of food cooked in these pots, coupled with other sources from the environment, diseases such as loss of memory, damage to central nervous system, dementia and severe trembling could occur.

Are clay pots better than aluminium or stainless steel pots? Dr Kayode Adedapo, a Consultant Chemical Pathologist, Department of Nuclear Medicine, University College Hospital (UCH), Ibadan, Oyo State, stated “it is not a question of which cooking pot is the best because such advice needs to be backed up with lots of research.”

According to him, “clay contains many minerals like silicon that over time may also leach into food when it is used to cook. But where the cooking pot is made from a particular material, say aluminium, its concentration in the food will be more.”

Although other nutrients in clay, he said may be beneficial when an earthen pot is used to cook food, thus making it a better option for cooking, he stated that there are anecdotal evidence that foods cooked in clay pots tend to retain their flavour more than those with other cooking pots.

In recent times, many health conscious people started to consider the use of clay pots. It is being promoted as inexpensive, healthier and provides some beneficial tastes in some traditional dishes.

Nonetheless, Mr Tunde Ajobo, a chief dietetics, UCH, Ibadan, stated that substances that might be released into food will be determined by the composition of clay used in moulding the pot and the length of cooking time.

According to him, the more the clay pot is heated, the more the constituents of the pot that could leach into the food being cooked.

But, the use of clay pot is more beneficial in cooking vegetables. “If you want the best of your vegetable, do not use metal cooking pot, go for clay pots. It retains its greenness or chlorophyll content better because more of the heat is absorbed directly by the clay pot as compared with either aluminium or steel coated pots,” he said.

Clay pots are also alkaline in nature, so, they mix well with acidic food to perfectly balance out the pH level of what is cooked, making it healthier.

Whatever the choice of cookware, keep it scrubbed scrupulously clean with soap and water, do not use harsh scouring pads or cleaners, and follow manufacturers’ care instructions. New pots are definitely better than old ones, with the possible exception of cast iron.

Avoid non stick pans, pots, bake ware and utensils because they contain Teflon. Teflon is made from perfluorinated compounds which have been linked to cancer and reproductive problems.

Non stick kitchenware whose coating is coming off or clay pots that is cracked or chipping should also be avoided. Glazes used in ceramic dishware often contain lead.