By John Messmer, MD

If you read the label on many foods, you might see a statement that says something like: “BHA and BHT added to preserve freshness.” Lately, reading food labels can make you feel like you need a short refresher course in chemistry. With all these unknown additives and strange sounding names, it can be quite intimidating if you’re trying to eat a decent diet. How safe are these chemicals anyway?

Why are BHA and BHT added to our foods?

Many foods contain fats. When fat is exposed to air it oxidizes, that is, it combines with the oxygen in the air. Oxidization makes fat rancid. And rancid food smells and tastes bad. BHA and BHT are antioxidants which prevent fats from turning rancid by inhibiting their reaction to oxygen. Other antioxidants exist, but they change the taste or texture of food. BHA and BHT do not change food and are only required in tiny quantities to do their jobs.

What are BHA and BHT, exactly?

BHA is butylated hydroxyanisole, and BHT is butylated hydroxytoluene. Although their names are not very appetizing, without them many packaged foods would spoil before they reached the stores or soon after you purchased them. With them, bread stays fresh for several days instead of just one. Crackers and snack foods stay fresh for months if the package is not opened. Butter and shortening can be kept for much longer with BHA and BHT.

Are BHA and BHT safe?

Naturally, people worry whether BHA and BHT are safe. These chemicals are added in parts per million or billion, a quantity so miniscule it is negligible. They have been tested repeatedly over the years and no harmful effects have been found in the concentrations used in our foods.

Food additives are tested for safety by giving extraordinarily large amounts to test animals, such as rats. Since the lifespan of rats is short, scientists believe that problems will be noticeable sooner than over the lifespan of humans who ingest normal amounts. When rats are fed massive quantities of BHA and BHT, some health problems have developed. However, these results are probably negligible when determining their importance for human safety since there are many things we can consume safely in small quantities but would die from in massive amounts. For example, medicines like aspirin, vitamin A, acetaminophen, fluoride, and iron would kill us in large quantities. Similarly, small doses of ultraviolet light on our skin is necessary to help us make vitamin D, but large amounts of ultraviolet light cause skin cancer.

Nothing is absolutely risk free, but the accumulated knowledge about BHA and BHT supports its safety for usage as an antioxidant in food. When foods have longer shelf lives we save money, too. So, enjoy your ability to go to the pantry and have a stock of food that has remained fresh and tasty due to BHA and BHT.