// posted March 28, 2007 by Lou Schuler

I once knew a pregnant vegetarian. She was one of the most judgmental people I've ever known, a self-righteous scold who took offense at pretty much everything. Unfortunately, she was married to a friend of mine, so we had to find ways to engage in polite conversation when we found ourselves in the same room.

About the only time I ever liked her was when she was pregnant. She told me she'd started craving beef, and had to back off from her militant vegetarianism for a while. I liked hearing that, not because I care one way or the other what vegetarians do, but because it seemed to give her an insight into what it means to be human. Sometimes you have to do what your instincts tell you to do, and instincts rarely follow a strict ideology.

I bring that up because of this story about the perils of maternal meat-eating:

U.S. women who eat a lot of beef while pregnant give birth to sons who grow up to have low sperm counts, researchers reported Tuesday.


They believe pesticides, hormones or contaminants in cattle feed may be to blame. Chemicals can build up in the fat of animals that eat contaminated feed or grass, and cattle are routinely given hormones to boost their growth.


"In sons of 'high beef consumers' (more than seven beef meals a week), sperm concentration was 24.3 percent lower," the researchers wrote in their report, published in the journal Human Reproduction.

More than seven burgers or steaks a week? How many pregnant women actually eat that much beef? Turns out, that's a telling question:

The team at the University of Rochester Medical Center in New York studied data on the partners of 387 pregnant women in five U.S. cities between 2000 and 2005, and on the mothers of the fathers-to-be.


Of the 51 men whose mothers remembered eating the most beef, 18 percent had sperm counts classified by the World Health Organization as sub-fertile.


"The average sperm concentration of the men in our study went down as their mothers' beef intake went up. But this needs to be followed carefully before we can draw any conclusions," said Shanna Swan, who led the team.

You start with 387 pregnant women. You track down their baby daddies. Then you track down the mothers of the baby daddies. Of those, you find 51 who remember eating beef more than seven times a week when pregnant. And you discover that nine* of the men who sprang from the loins of those 51 women have low sperm counts.

Quick show of hands: If you asked your mother what she ate when she was pregnant with you, do you think she'd remember accurately?

Dr. Swan thinks she would:

"When you are pregnant you are very aware of what you eat -- you are watching your weight and some things make you sick and you need to get enough of x and y so you focus on that," she said.


The mothers of the men were asked only if they ate beef more than once a day or less -- something Swan believes they could remember accurately.

She's studying something important -- low sperm counts in contemporary men -- so I'll give her some slack on this. But still, it seems like a pretty big conclusion to make based on such shaky evidence. Pregnant women are already freaked out over the mercury in fish. Is it really worthwhile to get them freaked out over the hormones in beef?


* Reader Rob Siders pointed out a typo in my original version of this post. I misread the article I was quoting, and thought it referred to 18 people, when it clearly said 18 percent of 51 people. He did the math for me -- that's nine moms who bore sons with low sperm counts, which actually makes a better argument against taking the study seriously.

Tags: Family/Parenting