Hormones in beef, a thought

Don at Primal Wisdom recently had a post on hormone levels in beef, which was really about whether or not hormone-treated factory farmed meat is unsafe*, but I was more interested in hormone levels in general.

I once had a native African explain to me that among her people, they have a taboo against hunting female animals. This taboo makes a lot of sense for a tribe dependent on hunting. If you kill a female, you are eliminating a bunch of potential offspring at the same time; while killing a few bulls will have essentially no effect on the fecundity of the herd.

So hunters would have preferred eating bulls to cows, and in Europe still today some producers raise bulls. Similarly, in the U.S. we get most of our beef from steer—neutered bulls—while we save the cows for calving and milk production.

Bulls and steer differ hormonally. Bull meat samples tested by Fritsche and Steinhart [1] contained medians of 0.34 mg/kg testosterone and 0.32 mg/kg epitestosterone, while steer meat samples (from unsupplemented steers) contain medians of 0.01 mg/kg testosterone and 0.12 mg/kg epitestosterone. Bull meat had up to 1.05 mg/kg testosterone. Thus, bull meat contains a median of 34 times more testosterone and more than twice as much epitestosterone than steer meat; and bull meat might have up to 105 times as much testosterone as a steer.

I've also read about these taboos. A long time ago I took a class on African agricultural economics and did a paper on how food taboos protected resources. Many cultures have taboos against killing young, lactating, pregnant, or female animals. It makes sense.

But maybe our beef these days doesn't have enough testosterone because we are consuming steers rather than virile males? As Tim Ferriss says in Four Hour Body "The sperm counts of men in the United States and 20 other industrialized countries have been falling since 1942 at a rate of roughly 1% per year in healthy males."

As an aside, many cultures have male virility rituals which involved the ingestion of animal penises and testicles or human seminal fluid. 

It's an interesting thought I'll just throw out there, which came to mind when Ulla Kjarval tweeted me that she thought us paleos would be most interested in her father's bull meat for sale. Her father, Ingimundur Kjarval, has a grass-based farm and blogs at healthymeat.org. If you are in or near NYC you can vote for Meatshare to buy it.

* I think we don't know and even if wild animals have high hormone levels, animals treated with the synthetic stuff still might be different. I prefer to take the precautionary approach. And there are other reasons not to eat factory farmed beef, though I think it's a better choice that factory chicken or pork because it spends some time on grass.