A recent study by Centre for Science and Environment (CSE) has found potentially cancer-causing agents in 84 percent of the 38 brands of commonly available bread samples including Britannia Industries, McDonald's, Subway, Pizza Hut and Domino's.
34 of the 38 brands tested positive for potassium iodate and potassium bromate – additives that are banned in other countries for their “hazardous” effect on health. While potassium iodate falls into the category of 2B carcinogenic (potentially carcinogenic to humans), various studies have found that potassium bromate can cause thyroid disorders.
However, according to a PTI report, India has not banned their use.
Here’s what you need to know about how the two chemicals find their way into your food and how they affect your body.
Potassium Iodate
Why it is used –
The white powdery substance, in trace amounts, is used for iodination of table salts to prevent iodine deficiency and as an ingredient in baby milk.
The WHO also recommends its use to protect radiation from radioactive Iodine whereby its tablet aids excretion of radioactive material from the body. As a preventive agent, it is used to curb accumulation of iodine in the thyroid gland.
It is also used as a fast-acting dough-oxidizing agent that works in the mixer to fully develop the dough.
How it affects you -
Potassium bromate
Why it is used –
It is essentially used as an oxidizing agent in bread flour in order to bind the gluten molecules of the bread together to give it the soft and flexible texture. However, these gluten molecules do not bind together naturally, which is oxidation is necessary.
Before additives like potassium bromate were introduced, bakers would use oxygen from the atmosphere itself. However, this was a time-consuming process, spread over days, where bakers would mill the flour and keep it in open air for quite a few days. They would add more flour to the dough slowly, so that the oxygen in the air could be used for the molecules to bind together.
However, using potassium bromate proved much quicker. According to an explanation on Live Science, the additive “enhances its (the bread’s) elasticity by strengthening its network of molecular bridges, which makes for the formation of tiny, thin-walled bubbles as the bread rises.”
If the process is followed correctly, the final bread should not have potassium bromate at all. When the bread is baked at correctly, the compound changes to potassium bromide, which is a harmless byproduct. However, many times when the additive is added in larger amounts or if the bread is not baked at a high enough temperature, residue of the harmful potassium bromate remains.
How it affects you –
Studies have been conducted on rats to ascertain the effect of the agent have found that it is carcinogenic for both rats and humans. Further, it was also found to have a damaging effect on kidneys. Another study indicated that it significantly reduced their RBC (red blood cells) count, platelet count, protein and Albumin in Swiss albino mice. Other studies have also found that when potassium bromate is present in over a certain quantity, it renders the bread unsafe for human consumption.