BHT and BHA are antioxidants.
Antioxidants are usually added to foods to preserve fats. Oxygen will react preferentially with them, instead of oxidizing (and spoiling) the fat. Both BHT and BHA
have bulky hydrocarbon groups connected to a phenol ring, which
makes them both fat-soluble and oxidizable.
Vitamin E, a natural fat-soluble antioxidant, has similar structural features.
These substances are believed to be safe,
but there is some controversy about the use of BHT and BHA in foods. While these compounds may
combat
oxidative stress
and may even slow aging, a few isolated studies suggest that BHA, BHT, and other antioxidants might be carcinogenic agents.
Author: Fred Senese senese@antoine.frostburg.edu