Funny you should mention -- I did a double-take awhile back when I discovered some people were taking the preservative BHT as a dietary supplement (can't call it medicine per the FDA). It's supposed to have an antiviral effect. The first time I saw the initials was when I would read the ingredients on the back of the cereal box, paired with its cousin BHA.
I am not up-to-date on this stuff. So, Wikipedia comes to the rescue.
Butylated hydroxytoluene (BHT), also known as dibutylhydroxytoluene, ... is useful for its antioxidant properties. European and U.S. regulations allow small amounts to be used as a food additive.... forbidden as food additive in Japan (since 1958), Romania, Sweden, and Australia.
The National Cancer Institute determined in 1979 that it was noncarcinogenic in a mouse model.
Since the 1970s, BHT has been steadily replaced with BHA.
OK, so BHA should be safer or less controversial, right?
Butylated hydroxyanisole (BHA) is an antioxidant ... a waxy solid used as a food additive... The primary use for BHA is as an antioxidant and preservative in food, food packaging, animal feed, cosmetics, rubber, and petroleum products. BHA also is commonly used in medicines, such as isotretinoin, lovastatin, and simvastatin, among others.
The U.S. National Institutes of Health report that BHA is reasonably anticipated to be a human carcinogen based on evidence of carcinogenicity in experimental animals. In particular, when administered in high doses as part of their diet, BHA causes papillomas and squamous cell carcinomas of the forestomach in rats and Syrian golden hamsters. In mice, there is no carcinogenic effect, and even evidence of a protective effect against the carcinogenicity of other chemicals.
When examining human population statistics, the usual low intake levels of BHA show no significant association with an increased risk of cancer. The State of California, has, however, listed it as a carcinogen.
So, BHA causes cancer in rats and hamsters, but fights cancer in mice. For human, it is not bad, except for those living in California.
It's clear as mud.