Milk and rBST

Recombinant bovine somatotropin (rBST) (aka cow growth hormone), is routinely used to increase milk production in cows. This hormone is banned in Canada, European Union, Australia and New Zealand but the United States continues to allow it.

The National Institutes of Health states that rBST is not present in significant amounts in milk as it is destroyed during the pastuerization process. However, rBST causes an increases in levels if IGF-1. IGF-1 is present in cow's milk and survives the pasteurization process.

The obvious question is, "So what? Is consumption of extra amounts of IGF-1 in cow's milk harmful to humans?"

This journal article makes some important points about IGF-1.

1. Milk protein consumption induces postprandial hyperinsulinaemia and shifts the growth hormone/insulin-like growth factor-1 (IGF-1) axis to permanently increased IGF-1 serum levels.

2. Insulin/IGF-1 signalling is involved in the regulation of fetal growth, T-cell maturation in the thymus, linear growth, pathogenesis of acne, atherosclerosis, diabetes mellitus, obesity, cancer and neurodegenerative diseases, thus affecting most chronic diseases of Western societies.

3. Of special concern is the possibility that milk intake during pregnancy adversely affects the early fetal programming of the IGF-1 axis which will influence health risks later in life.

Clearly, disruption of the IGF-1 axis has significant implications.

Folks, many people will tell you that even if we give rBST to cows, it is not a big deal because it doesn't make its way into milk. But that approach is incredibly short sighted. rBST does something to cows... that something is an increase in IGF-1. IGF-1 enters our body and according to some authorities, has a significant role in most chronic diseases.

Milk has the potential for damages. So is organic milk better for you? We'll address that in the next entry.