Potassium Bromate: Food Additive and Carcinogen?


Home / Potassium Bromate: Food Additive and Carcinogen?

Bread, a staple in most western diets, contains additives. Bromates may be one of many additives. Copyright Image by Decoded Science, all rights reserved.

Malnutrition became a distant memory for most during the 20th century. Adding vitamins, nutrients, and preservatives to foods helped minimize malnutrition. Adding these ingredients to increase nutritional values, taste, texture, and so on made sense, as did the development of pesticides and chemical fertilizers. Indeed, the Post-WWII world seemed promising – yet not all chemicals would prove beneficial in the long haul.

The Chemistry Cure

The chemistry ‘cure’ came under close scrutiny during the late 196os, as activists attacked the philosophy: “Better living through chemistry.

Rachel Carson’s hallmark book Silent Spring became the voice of the dissidents, explaining that synthetic chemicals could poison the landscape and us.

Ms. Carson’s book helped launch the environmental movement of the 1970s, as science began to scrutinize the use of synthetic chemicals such as DDT and Potassium Bromate.

Potassium Bromate; a Case in Point

Chemists first added potassium bromate to wheat flour in 1916, when it replaced more toxic bread additives such as nitrogen chloride. Potassium bromate then became the go-to additive for wheat flour in the mid-20th century, though its use is presently discouraged in the US. Scientists in Japan, studying potassium bromate, found that it was a cancer-causing agent during the mid-1980s. Studies in other countries verified this, and the damage to potassium bromate’s reputation began, despite the usefulness of the chemical to food manufacturers. 

Why is Potassium Bromate Useful?

Bread was not originally the fluffy, sweet product we currently consume. During the American Civil War, for example, a variety of bread known as ‘hard tack’ was a staple item of soldiers. Bread made without conditioners can vary in consistency, so bread’s transformation to its present state was partly due to additives like potassium bromate.

Potassium bromate is an inorganic compound, a whitish powder that resembles wheat flour. It helps bread rise uniformly. During baking, gas is released, imparting the bread its fluffy texture. In cakes, the chemical binds with egg products to provide a firmer consistency, making the cake less crumbly.

Chemistry of a Dough Conditioner

Potassium bromate allows baked goods to achieve uniformity. In pound cake, for example, studies have shown heat denatures egg protein, resulting in less protein content in the end product. Egg whites contain ovalbumin, a protein that enables bond formation between flour, fat (butter), and itself with the help of the bromate. One of the bond varieties — disulfide bridges – forms between proteins.

To visualize the process, including the release of oxygen during the baking process, imagine the following:

  • The dough sets, as heat is applied.
  • As it sets, the dough becomes less fluid and more gelatinous.
  • The bromate increases the likelihood the cake will not collapse. (Cakes may collapse curing the baking process if the egg and wheat gluten proteins do not form a cohesive network; as mentioned before, bromates delay the denaturation of egg proteins.)

What is Wrong with Potassium Bromate?

Potassium Bromate is an oxidant – and like many oxidants, it can form free radicals. Free radicals can induce inflammation and affect DNA via the process of DNA methylation. In this process, free radicals break strands of DNA and then cap them with other chemicals. The methylated DNA may promote cancer even years after exposure.

Silencing Spring?

Potassium Bromate was used by the US baking industry since 1916, Its use is discouraged in the US. Copyright Image by John A Jaksich. All Rights Reserved

Rachel Carson’s early warnings were ominous, and apply to the current generation: Technology, too quickly adopted, may result in problems. Adding bromates to baked goods seemed an excellent idea; it was only with time that we began to recognize the health risks.

It is our continuing quest to understand chemical phenomena that allows society to extend lifespans and correct past errors in judgement.

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