Does BHT in Food Cause Cancer?
If BHT, a common preservative, were known to cause cancer it would never be allowed as a food additive. Regulatory agencies are in the business of protecting not endangering the public. The function of BHT is to prevent rancidity, the result of the breakdown of fats into odorous smaller molecules in the presence of oxygen. These compounds are not by themselves dangerous but may signal that the food has been around longer than it should be. Fats which contain double bonds in their molecular structure, called unsaturated fats, are especially prone to oxidation. A number of additives are available to slow down this process by reacting with the intermediate highly reactive free radicals which play an essential role in the chain reaction characteristic of rancidity. BHT (butylated hydroxytoluene), BHA (butylated hydroxyanisole) and propyl gallate are widely used in potato chips, vegetable oil, shortening, candy and a variety of convenience foods at a usual concentration of 0.01%.
BHT is often added to cereal packaging, from where it migrates into the cereal, in order “to help maintain freshness.” Like all food additives, BHT (butylated hydroxy toluene) has had to pass stringent efficacy and safety standards but that doesn’t mean there have been no studies that raise questions. A few studies have suggested that it may cause cancer in some animals at some dose but the vast majority of studies have shown no such effect. Some have even shown protection against the disease. In one study, rats lived longer by a man-equivalent of twenty years when fed BHT, in another, the same chemical was judged to be responsible for the production of abnormally high levels of liver enzymes in laboratory animals. Overall, the studies indicate an acceptable risk-benefit ratio.
In any case, antioxidants are not essential. They lengthen the shelf life of cereals from about four months to one year. This is not necessarily beneficial since other degradative processes leading to staleness and loss of flavor are not hindered by BHA or BHT. The fact that even in identical products not all manufacturers use these chemicals implies that they are dispensable. Furthermore, most products which are preserved with BHA and BHT can be criticized on other nutritional grounds, such as their high fat content, and should be minimized in the diet.