Ask your Doctors: How Common are Allergies to BHT (a Food Preservative)?

The preservative BHT in many foods really can do a disservice to me. BHT is a preservative in many food products. I have experienced severe headaches, nausea, stomach upset, fever, and other symptoms after eating one serving. These allergies are quite common. How do I prevent them from happening?

BHA, or butylated, hydroxyanisole, is an antioxidant used in preserving a variety of foods. These include snacks, meats, butters, chewing gum, rice and many other food items. It also protects cosmetic products, medications, and medicines. BHA as well as BHT help prevent oils from oxidizing, which helps to preserve product crispness in certain foods, such breakfast cereals and baked goods.

These antioxidants rarely cause allergic reactions. The first official evaluation of this compound was done more than fifteen years ago. It was tested in a placebo-controlled study that involved two patients with hives. They were initially exposed to BHA/BHT through foods, and then to placebo. These two ingredients were eliminated from the patients' diets, which resulted in a decrease in their symptoms and frequency. In 2007,a study published in Toxicology and Applied Pharmacology identified the mechanism for the allergic reaction. In studying rats given BHT, researchers found an increase in immediate skin allergies, linking it to an allergic response that caused a type of white blood cells, known as mast cells, to release the chemicals histamine and leukotrienes. This caused an allergic reaction in the skin. There are still questions about the effects of these chemicals on the skin and how they cause allergic reactions. Researchers have not yet found evidence that BHA can cause nasal allergies or asthma.

BHA, in particular, has been seen as increasing cancer risk. This worry stems from studies in rats and hamsters in the 1980s. One notable study showed that rats fed diets with up to 1 to 2 percent of BHA had increased cancers of the stomach. A diet that contained 1 percent BHA resulted in 20 percent developing stomach cancers. If a diet had 2 percent BHA it produced 100 percent stomach cancers. The highest level of BHA approved for food in the United States is 0.02 percent. This is significantly lower than the US average. Overall, some studies in rats have shown an increased risk of cancer, and others have shown a decreased risk in cancer.

Human research has not shown any link between cancer and BHA/BHT. In a study published in 2000 in Food and Chemical Toxicology, researchers in the Netherlands used a dietary questionnaire to ask 120,000 men and women between the ages of 55-69 about their dietary intake of BHA and BHT. The authors discovered no rise in stomach cancer for those who ate more BHA/BHT after six years.

The very small amounts of BHA/BHT in cosmetic products has not been associated with cancer.

BHT seems to cause allergies. It is best to avoid the chemical. As I was writing, I checked the food in my home to see if it contained BHA and BHT. However, only one of these items did. It seems that you can eliminate home exposure to BHA/BHT simply by paying attention to labels.

You will need to exercise caution when going out to eat. You should avoid processed foods and opt for whole, plant-based, healthful food. Particular attention should be paid to the sauces. Be sure to check the sauces on any food you order.