Milk, in its human form, has been the foundation of nutrition for hominid infants for millions of years. In the past few millenia, animals have been domesticated for milk and meat. Many of them are ruminants, but not all are. The camel and the horse are notable exceptions, highly regarded in several cultures for their milk.
In the western world, kine (aka cattle), (Bos) are almost exclusively used for providing milk in useful quantities. As a matter of fact, in the United States this is such an important agricultural industry that entire sets of laws and price supports have been enacted.
This essay looks into the the issue of milk that is produced with Bovine Growth Hormone (BGH), (also called Bovine Somatotropin (BST))and will likely prove to be controversial. This is an important issue, and I will attempt to give it a fair treatment, but remember that many folks have already made up their minds without considering the actual data, and it is difficult to make folks who have already made decisions based on emotion to see logic. With that said, here we go.
First, some housekeeping. I still have not bought cigarettes since March of this year, and I am cutting down on the hand rolled Prince Albert ones.
Second, it is becoming more difficult to choose a subject, research it, and write on it because of my personal situation. Those of you who follow my contributions closely will understand to what this refers. That is why The Geek did not appear last week. It looks like things will be final within 30 days.
Third, those of who who follow my contributions closely realize that I have the ability to take scientific data, assimilate it, and provide what I think is a relatively unbiased summary of it that nontechnical people can understand, but also not boring for technical people. If you have any contacts with organizations that need that kind of that ability to get out their message, please contact both them and me. I need the work, and want to do for pay free lance work beginning immediately.
Milk is a product produced by the mammary glands of female mammals, and is unique. It is closely related to sweat, but has many more nutrients than sweat contains. The cells that produce milk are very closely related to sweat glands, but have some interesting permeability differences. First of all, sweat glands have evolved to secrete mostly water and salts, with only a few traces of proteins and fats. Milk cells have evolved to produce not only the water and electrolytes, but a large amount of lipids and proteins as well.
Sweat pretty much has only one function: thermal regulation. The evaporation of the water in sweat cools us by evaporation (well, not so much in very humid areas), and also takes some pressure off of the kidneys to eliminate sodium and chloride. In most cases, water and salt are common and not what we would call extremely valuable to the organism. In normal circumstances, we get plenty (if not too much) of each.
Milk incorporates the water and salts, but adds protein and fats. Proteins and fats are extremely valuable to the organism delivering them, so there has to be a reason. That reason is that mammals are the only class of animals that take care of their young as a rule rather than as an exception. From mice, to rats, to cats and dogs, to whales, and to people, the female has evolved to feed her offspring not from a yolk sac that is laid in the ground or water, but from her living body, implying a strong bond with the offspring. That is the genius of mammals, and why mammals have become one of the dominant branched of living things in the past few millions of years.
The philosopher in me says that there are even deeper reasons. The contact between offspring and mother forms a bond across which information is exchanged. Maybe not so much for mice (although I am not convinced that they do not as well), but for whales, dogs and cats, and especially humans, this information exchange is paramount. The bond between sentient species (all of which on our planet seem to be mammals) begins with the offspring suckling the mother. I do not mean to be dramatic, just factual.
Well, in the past several thousands of years in which agriculture developed, we have learned that the milk of other mammals can substitute for some degree with the natural milk of the human mother. This was a relief, because human infants often have caloric requirements greater than can be provided by the natural mother due to poor nutrition or other factors. For most of us, that means cow’s milk.
I have a disclaimer here. When I was an infant, I could not tolerate cow’s milk. My skin literally broke out into weeping sores when I was one year old. Doctor Post, bless him, recommended that I be switched to soya based formula, and it saved my life. This was in the era that breastfeeding was thought to be “trite”, as I was born in 1957. My mum was discouraged to breast feed me, as the thoughts at that time were that breastfeeding was not scientific, and formula would be better. They got that one wrong.
In any event, I got over my cow’s milk allergy by the time that I was three or four years of age, and drink at least a little milk, and eat cheese, every day of my life. But none of it is human milk (that would be a bit kinky for a man of my age), all of it is cow’s milk.
Dairy farming is big business. In the United States alone, almost 80 thousand million kilograms are produced each year. Like any other business, getting more for less makes economic sense. Thus, BGH (specifically, recombinant DNA BGH, or r-BGH was introduced in the early 1990s to increase milk production. Cows given this hormone produce around 11% - 16% more milk than cows not so treated, allowing smaller herds for the same production. However, this has been a very controversial practice for several reasons.
First, let us take just a minute to review what growth hormones do in animals. In both cattle and humans, in the young, growth hormone causes increase in size the young, up until maturity when bone size stops increasing. In particularly small children, recombinant human growth hormone is given to help them attain normal stature. In adults, growth hormone is still important, maintaining bone density, modulating the immune system, and many other important functions. Too little can lead to osteoporosis, whilst too much can lead to acromegaly. Thus, some but not too much is required by both cattle and humans. The bovine kind differs from the human kind by a few amino acids (they are both polypeptides), just for the record.
Recombinant BGH is identical to the natural one, but is much cheaper to produce and so is used exclusively. Since cattle digest it when it is fed to them, it is injected. Sure enough, milk output is increased. Most studies have shown that there is very little difference, if any, in the nutrient profile of milk produced with BGH than milk produced without it. The National Institute of Health and FDA have both reported that oral human consumption of milk and meat from BGH treated cattle has no effect on the health of people who consume them. Thus, the concern that BGH will affect humans consuming milk and meat (remember, retired dairy cattle are one of the largest sources of ground beef) is really unfounded.
A second concern is the issue that levels of insulin-like growth factor 1 (IGF-1) may be raised in milk from cattle treated with BGH. (Human and bovine IGF-1 are the same). IGF-1 has been, justifiably, in several human diseases, including some cancers. However, just like HGH, we need some IGF-1 as well, but not too much. It acts with HGH in childhood and adolescence to promote growth, and has several actions, not all of them well understood, in adults. It shows some promise as an adjunct therapy in both types of diabetes, although it seems to have some negative side effects. Nonetheless, we all have it in our blood serum at 100 - 200 nanograms per milliliter. BGH milk contains 1 - 13 nanograms per milliliter, so to double one’s serum concentration one would have to drink 19 liters of milk at a setting, assuming an average adult blood volume of 5 liters (blood is about half serum, the rest red and white blood cells), a normal level of 100 ng / mL, and milk at the upper limit of 13 ng / mL. This is five gallons of milk, and it also assumes 100% absorption of IGF-1. If you use numbers of a normal 200 ng / mL concentration and the 1 ng / mL milk, you would have to drink 130 gallons. This assumption is not a good one, since a significant amount (perhaps all, but no studies have been done in humans) of IGF-1 is digested and thus rendered inactive. On top of that, non-BGH milk also contains IGF-1, at levels not much lower than in BGH milk. This issue is also a non-starter.
So, why the controversy? I can think of a couple of reasons. The first one is a general public distaste for recombinant DNA materials, the “Frankenfood Fear Factor”, as I put it. I have news for you: just about all insulin on the market now is recombinant. (Interestingly, cattle and pork pancreases were the source of pharmaceutical insulin until the recombinant human kind became widely available). Now, I think that we might be carrying out recombinant DNA foods too far sometimes, but the reality is that it is here to stay. By the way, over 90% of soybeans grown in the US are genetically modified, as is most of the corn for industrial purposes (but not for food). In the case of BGH milk, I think that this fear is very much out of proportion to any risk that might exist.
Another reason is that the evil Monsanto develvoped r-BGH. I have said before that I am not a fan of Big Agriculture, but just because a company with less than ideal ethics, in the opinion of many people, does not make a given product evil in itself. It is easy to demonize a product because it was produced by a corporation that is unpopular with a significant section of society, particularly when the voices against such a product are very passionate if in fact incorrect or outright deceptive. As an example, consider the job that Fox “News” Channel, Limbaugh, Palin, and the other extreme far right have done with the end-of-life discussion reimbursement proposal in HR 3200. Instead of being what it is, paying a physician to discuss options with patients on a voluntary basis, it has been demonized into a mandatory order to “pull the plug” on Grandma. When zealots repeat questionable information often enough, people who do not do their own critical thinking just believe them, especially when the product is not well understood and comes from a source that is not implicitly trusted, and Monsanto is not trusted by a large number of people.
I do have one major concern with BGH, that that has to do with the health of the animals. They are the ones getting the doses, and obviously have the most significant effects because of the relatively large amount (compared to what is in the milk) of the drug. Mastitis, an inflammation of the udder of cows, is somewhere in the ballpark of 25% greater than in untreated cows. This is a painful condition, and anything that increases pain in domestic animals is not a good thing. We treat them poorly enough to begin with, although dairy cattle get better treatment than most commercial domestic animals. Humans can also get mastitis, and if any female reading this has ever had it, I am sure that you can vouch for the fact that it is a painful condition. Mastitis also an economic problem, because the milk from cows with mastitis is unusable.
The use of BGH is decreasing in the United States for several reasons. For one thing, public pressure in making it go out of favor. As a matter of fact, my jug of Kroger milk says that Kroger buys milk only from herds not treated by BGH. Dean Foods, the largest single milk producer, also will not buy BGH milk, and several other large retailers, including Wal-Mart will not either.
Another reason is the cost of the BGH. It is not free, so the increase in milk production is offset by the cost of the drug. In addition, the food value in the milk has to come from somewhere, so with higher milk production comes higher feeding rates, and thus feed costs.
The market is currently tilting away from BGH as well, because the price for milk is low compared to a couple of years ago. Dairy farmers are producing more milk than they need and profit margins are very low, even negative in many cases, currently. There is no incentive to produce more milk at present, but rather to lower costs.
I think that BGH will be a thing of the past relatively soon, not from regulation but from public pressure and associated costs. This, except for the animal health issue, is really not one that we should be worked up about, in my opinion, but rather should focus our energies on real, serious issues in food production, like antibiotic use for other than therapeutic reasons. This is an open secret that, while the information is available, hardly anyone is familiar. Maybe that would be a good topic for next time.
Well, you have done it again. You have wasted another perfectly good batch of photons (thanks to Kossack science for correcting me last time) reading this drivel. And even though Samuel Wurtzelbacher (aka Joe the Plumber) decides not to beat up Nancy Pelosi when he reads me saying it, I always learn much more than I could possible hope to to teach by writing these essays, so keep comments, corrections, questions, and opinions coming. Remember, on Pique the Geek, no science or technology question is off topic in the comments.
Warmest regards,
Doc
Crossposted at Dailykos.com
1 comments
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for good, healthy dairy products?
Warmest regards,
Doc