Part of the joy of drinking raw milk and partaking of other locally-produced and non-processed foods is being more a part of a natural system, a cyclical system that revolves around seasonal changes, old-fashioned grazing, and animal reproduction cycles.
Well, it’s this last point that may create a problem for my raw milk consumption. A friend who knows of my interest in raw milk sent me an article from the current issue of Harvard Magazine, which quotes a Mongolian physician expressing concerns about the natural hormone levels of milk (excluding BGH-fed cows). Her research indicates that much of our milk has high levels of estrogens, which have been implicated in hormone-dependent cancers like those of the prostate, breast, uterus, etc.
This physician became interested in the subject of milk when she noticed differences in dairy practices between her native Mongolia and Westernized countries. In Mongolia, pasture-fed cows are milked only through the first three months of a pregnancy, when hormone levels are still low, while in Westernized countries cows are kept pregnant and lactating 300 days a year. And, indeed, she has found evidence that hormone-based cancers in Japan, which uses Westernized dairy practices, have increased since the 1950s at about the same rate as milk consumption increased.
I wondered when I read this whether the same practices apply to farmers producing raw milk, so I called the New Hampshire farmer who supplies me with my milk. She told me that cows have the same nine-month pregnancy cycle as humans, and she milks through the first seven months of a pregnancy; the last two months the cows get “a rest,” and then after birth the cows begin being milked again. This is all standard practice, she said, whether a farmer is selling milk raw or sending it off to a processing plant for pasteurization.
The cow that has been providing my milk, she said, is currently pregnant and due in September. That means she became pregnant in January, and is currently in her fifth month of pregnancy, well into the “high-hormone” period. This farmer has a second cow, but it is currently in its rest period.
I’m uncertain what to make of this situation. As someone who has had prostate cancer, I’ve been told to avoid consuming anything that would stimulate increased testosterone production. But would estrogen do that? There is a school of thought that recommends increased consumption of soy products for men as a way to reduce prostate cancer risks, because of soy’s natural estrogen. Confusing stuff.
Yet in the case of the raw milk, I’m thinking that maybe the best thing to do is avoid drinking milk produced by cows in the fourth through seventh months of pregnancy. That means I have to start shopping around for raw milk, and inquiring of farmers about the pregnancy status of the cows producing the milk.
Obviously, other people have their own special concerns. Indeed, the Harvard Magazine article quotes the researcher as suggesting that cows in late pregnancy should not be milked or, if they are milked, their milk should be labeled to show it comes from a pregnant cow.
I guess I can’t just assume the natural cycles are always working for me. But the advantage I have as someone buying directly from a farmer I know is that at least I can find out the real situation.
Of course the downside is not drinking milk whole, the way nature has made it. I’m sure the fat has many good nutrients that you would now be missing.
Decisions, decisions, decisions!
Another thought to consider is that milking animals do not ~have~ to be rebred. Last fall I experimented with milking a yearling doe through the winter… she’s still milking now, some 15 months later. It was enough successful (milk production does drop during winter milking, but picks up some in the spring flush) for me to consider putting half the herd on alternate breeding years, so that each goat would be bred once every two years.
Dairy cow farmers, however, may be very reluctant to breed every other year since cow gestation is nearly twice as long, with typically only one calf to show for it, either a keeper (heifer) or future hamburger (bull), with therefore relatively few offspring per cow’s lifetime. Farmers probably won’t want to cut even further into their profits by losing the income that even a bull calf would generate.
Answer for David’s hormone milk problem: Drink goats milk!
Jenny
The link:
http://www.foodqualitynews.com/news/printNewsBis.asp?id=76466
A couple of snippets:
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Writing in the journal Clinical and Experimental Allergy, Waser and co-workers report that consumption of farm milk, whether boiled or not, was associated with a reduction in the occurrence of asthma by 26 per cent, hay fever by 33 per cent, and food allergy by 58 per cent. No effect was observed for eczema.
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The American Lung Association stated that almost 20m Americans suffer from the condition – reported to be responsible for over 14m lost school days in children, while the annual economic cost of asthma is said to be over $16.1bn.
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"It is interesting that there was no difference in the farm milk results regardless of whether it was boiled before consumption. As boiling is likely to have been over-reported, this could indicate that pasteurisation is not as important as previously thought, as compounds other than microbes may offer a protective role," said Dr. Waser.
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"But despite our findings, we cannot recommend consumption of raw farm milk," he added.
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Just one which likely has a significant roll to play is that the cow’s natural cycle also begs for a spring calf. That’s when the grass is just getting tall and green, and the milk (if the cow is grass-fed!) is rich with the famous cancer-preventer, conjugated linoleic acid. A very reasonable question therefore could be this: Does following that natural cycle afford a balance between cancer causers and preventers?
I know there are a lot of assumptions in that question, but that is essentially my point–too little data leads to too many assumptions. When there is too little data, and there almost always is too little, my suggestion is to go with the natural indicators. Follow the natural cycles.
Our cow will be bred in late July, dried off in late December, and freshen in late April. I guess, according to the Mogolian physician, that puts us two months into the danger zone. But it sure seems like a very reasonable and natural cycle to me. It neither "pushes" our cow into higher than natural production, nor keeps us away from the CLA we desire, which, when milk is gone, we derive from the butter we made back in spring. (We’re making butter furiously right now.)
I would also guess that you’d need to look at what sort of estrogen was produced and the ratios for this to be meaningful.
Phytoestrogens (from plants) are a funny thing that I don’t think are well understood. The whole soy thing is way overdone I think – we should not be giving so much soy to young kids and the antinutrient effect of soy is of concern. Soy is also one of the most likely to be GMO foods we consume.
I see so many families who have given up dairy and where the kids are drinking gallons of soy milk every week. I’m really uneasy about this. Especially for girls.
Finally, even if the milk was high in estrogen would the effects of consumption be mitigated by a diet high in dark green leafy vegetables?
My understanding is that for humans goat’s milk is indeed superior to the cow for many reasons, but I’m not sure this is one of them.
One of the things that has been a constant as I have put more thought into my family’s food is that the more I know, the more I don’t know. Initially it was dizzying, confusing, and frustrating, not to mention time-consuming (this point is where I see friends interested, making a few changes, but then giving up). But I must have reached an equilibrium point of sorts, because now new concerns don’t cause panic, they send calmly me off for more information or at least on alert, but ultimately they simplify things for me more – the more industrial it is, the less often I choose it. I don’t have to spend time reading so many labels and ingredient lists anymore because I don’t deliberate or even pick those items up anymore or they don’t have labels. *Far* less internal struggle at this point. Seems more like fine-tuning than a major overhaul.
Back to the milk. The estrogen issue is perhaps one to keep our eyes on for more developing information, but I do like the idea of matching consumption to the natural cycle of the milking animals. It’s certainly better for the animals who are managed that way and perhaps for us as well. And why should our milk be different from my pattern of buying apples or anything else in season for not out of season? I guess I just need to learn a bit more about the natural seasonality of cow milk and make adjustments accordingly (getting the child to adjust consumption is the real difficulty :-). Seasonality of meat is another area I would like to make adjustments in consumption as I learn more about it and find appropriate sources.
I started getting goat milk a month ago when it became available from a small farm that also provides our eggs & some meat/poultry (& they deliver to me, woo-hoo!). I mostly planned to make cheese & yogurt with the goat milk. But we ran out of cow milk one day and my son never noticed the difference so now he is drinking goat milk, too. Perhaps we’ll even time our milk buying based on the goats, as they are following a more natural cycle than the cow milk that is available to us.
She pointed out the lactation is a "low estrogen" time to begin with – supressing ovulation. So she wondered what the concentration would be – and guessed it would be pretty low.
As we think of cycles, consider that human lactation is year round, and although it is looked askance at in our western culture tandem nursing happens frequently and nursing for two years and more is perhaps somewhat rare in the US but certainly commonplace in many cultures and with many of the moms I’ve worked with. I have trouble believing this is a dangerous practice because of concentration of hormones.
There would seem to be a natural safety switch for this — if estrogen levels were high, nursing would shut off.
Retrospective studies about diet can be very deceiving. Furthermore, one of the corroborating studies was done on rats with another very small, short one on children.
I’m sticking with the raw milk.
For sure! I’d think the problem for most modern humans is too much estrogen. If prostate cancer was truly caused by testosterone, then it would be most common in men age 18-30 instead of in men who are at an age where it’s more common to have low testosterone and high estrogen.
Here is an interesting blog that talks about the study in Harvard Magazine.
http://blogs.das.psu.edu/baumrucker/?m=200701