I've heard about the following substances before. They are rBGH (recombinant bovine growth hormone) and rBST(recombinant bovine somatotropin). They are two names for basically the same substance and are given to dairy cattle.
Bovine somatotropin (BST) is produced by a cow's pituitary gland in small quantities and it is used to regulate processes in their bodies. This hormone was once given to cows to increase milk production but it was expensive as the only source was dead cattle. Scientists learned how to use DNA technology to synthesize this hormone and created rBGH and rBST. These artificial growth hormones are a much less expensive way to increase milk production.
There are several issues that people have with the use of these artificial hormones.
- They are concerned about the health of the animal as there is an increased instance of mastitis, a reduction of fertility and increased lameness in animals given these substances.
- Milk produced by cows given the artificial hormones is not chemically identical to milk from cows not given the substance. Milk from the treated cows has a higher level of BST and IGF-1 (insulin-like growth factor), another hormone. BST, if consumed in milk, is destroyed by our digestive system but there is a concern with the safety of IGF-1. The substances has been shown to increase the risk of cancer. It is uncertain whether this substance is absorbed into the body or not during the digestive process.
- Cows given the artificial hormones are more likely to have to be treated with antibiotics and people are concerned about trace amounts of antibiotics appearing in milk from these cows.
The main problem I see with consuming milk from cows treated with these artificial growth hormones seems to be the higher level of IGF-1 which we are unsure about. Skeptics are quick to point out that the amount consumed in milk is minute but it could still be a concern.
Some folks take issue with the idea of using DNA technology to manipulate genes so they would avoid these products for that reason alone. I've addressed the use of GMOs already and my thoughts can be found on this post so I'll not go into that again here.
If you wish to drink milk from cows not treated with these artificial hormones, there is a list on Wikipedia of companies who supply it. It shouldn't be difficult to find.
Our last "banned" substances are BHT and BHA. Butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) are added to food to prevent spoilage of fats and oils. They can also be found in cosmetics.
The FDA classifies both substances as generally recognized as safe but the National Toxicology Program believes that BHA might be a human carcinogen - based on animal studies - and that BHT is linked to an increased risk of cancer in animals. The waters are murkier for BHT as there are studies that seem to show a decreased risk of cancer associated with the substance, as well.
Both substances are broken down and absorbed into the body when consumed. The problem is that we simply do not have enough evidence to know for certain how these substances interact with the human body.
It seems prudent to limit your intake of BHA and BHT if at all possible. I don't think we need to totally avoid them but eating less processed foods will go a long way in helping you consume less of these substances.
This concludes my series on food ingredients banned in some countries but not the United States. Part 1 is available here and part 2, here if you missed them.
If you are aware of any substances that I overlooked, please let me know!
Information for this post was obtained from the following sources:
Skeptics Stack Exchange
Image obtained here