BHT and BHA as Carcinogens

Written by Jane Yoon

We mentioned in the intro post to BHT and BHA that both antioxidants may be significantly harmful carcinogens. In this post, we will look into that claim more in-depth by observing test results from multiple experiments.

Tests have been done for years to find a consistent effect of these two antioxidants but there have been no consistent results. BHT and BHA's carcinogenicity remains a controversy.
Here are a few results found in two separate experiments (as presented by the abstracts):

• Experiment testing cytotoxicity* and apoptosis**-inducing activity of
  BHA, BHT, the two mixed in a 1:1 ratio, and BMP (2-tert-butyl-4-methylphenol)
  using human promeylocytic leukemia cell lines and human squamous cell carcinoma cell lines as test subjects instead of the usual rats.
  
  Results: Decrease in cytotoxic concentration (less cytotoxic) in order of BHA,BHT > BHA+BHT mix > BMP
  Inserting reactive intermediates showed to enhance cytotoxicity; antioxidants reacted with them, oxidized and produced cytotoxic radicals.

• Experiment testing effects of added BHA and BHT (separately tested) to the diet of rats.
  
  Results: BHA induced high incidences of papilloma and squamous cell carcinoma of the forestomachs. Enhanced carcinogenesis in the forestomach and urinary bladder in two-stage carcinogenesis. Inhibited carcinogenesis in the liver. (sufficient evidence of carcinogenicity)
  BHT not found to be carcinogenic. Enhanced the induction of urinary bladder tumors and inhibited that of liver tumors in two-stage carcinogenesis. Had no effect on carcinogenesis in the forestomach. Could be a promoter of thyroid carcinogenesis.

We will look at further significant and relevant studies as well as the science behind how these harmful radicals are produced when BHT/BHA reacts with another substance.

* cytotoxicity - the degree to which something is toxic to living cells

** apoptosis - a cell suicide mechanism

Inosinic Acid

Written by Adam Bronfin

We've decided to branch out a bit from our original group of food additives. We've chosen inosinic acid, a food additive mostly used for flavor enhancement.

Inosinic acid (inosine 5′-monophosphate, IMP) is a dietary nucleotide that has been associated with immunity and intestinal health. Infants that were fed milk fortified with nucleotides had an increased humoral antibody response. Dietary nucleotides enhance the intestinal absorption of iron, have trophic effects on the liver and intestinal mucosa, and reduce the rate of diarrhea . Nucleotide supplementation increases the amount of mucosal protein, the amount of DNA, and the length of small intestinal villi, which indicates that nucleotides may promote the growth and maturation of intestinal epithelial cells. It has been reported that the requirement for nucleotides increases during periods of rapid growth, periods of stress, and in immunocompromised animals.

Inosine 5′-monophosphate is the main umami compound in the meat of poultry, livestock, and fish, and plays an important role in meat flavor formation. Many studies have confirmed the close relationship between IMP, meat flavor, and acceptability of fish meat. Umami, which was discovered in 1908, is a primary element of taste, complementary to sweet, sour, salty, and bitter. The characteristic compounds of umami taste can be classified into 2 groups: monosodium glutamate, which results from protein hydrolyzation, and the 5′-ribo- nucleotide typified by IMP, which is degraded by adenosine triphosphate (ATP) in the process of muscle curing.