High-protein diet reduces fertility?

[zakur]

Story

Women on a high-protein diet, including those following the Atkins regime and some sportswomen, could be significantly reducing their chances of conceiving, a study involving animals suggests.

[...]

They fed female mice a normal diet of 14% protein, or 25% protein for four weeks before mating. Embryos from females on the high-protein diet implanted only 65% of the time, versus 81% for the normal diet. And only 84% of the high-protein embryos developed to 15 days, compared with 99% of the normal embryos.

"It's always hard to extrapolate from animals," says Randy Jirtle of the Duke University Medical Center in Durham, North Carolina, whose team studies the effect of diet on embryos. "But from this data it doesn't look like a good thing for everyone to eat tons and tons of meat."

However, Jeff Volek from the University of Connecticut says that blood levels of ammonium do not seem to increase in people on the Atkins diet, so levels in the female reproductive tract probably do not either.

Atkins responds

It is important to note that there was no mention of carbohydrate control in the research conducted by Dr. Gardner. The study subjects were mice, whichare herbivores. Whether or not these findings or effects would apply tohumans, who are omnivores, is unknown.

"The differences between mice and human embryos have recently been demonstrated by the ability to produce mice embryos from a single parent, a process that can not be replicated in humans," said Stuart Trager, M.D., medical director for Atkins Nutritionals, Inc. "This casts a large discrepancy on the ability to derive conclusions about the clinical implications of this study with regard to humans."

In fact, some studies show a positive correlation between controlling carbohydrates and female fertility. Dr. Eric Westman presented an abstract at the Society of General Internal Medicine's 2004 annual meeting on a study of women with polycystic ovary syndrome treated with a controlled-carbohydrate approach.(1) On average, the women experienced improvement in hormonal levels as well as weight loss. In addition, two of the women in the study who had previous experienced difficulty in becoming pregnant, conceived during the study.

More here.

 

[c0rbin]

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[Goshawk]

They don't say where they got the "protein" from for the mice's diet, whether it was animal protein or plant protein. I'm assuming that it was animal protein. If so, then I wouldn't be surprised that a diet high in animal protein would adversely affect mice's breeding success, because as Atkins' rebuttal pointed out, mice are not naturally carnivorous--they normally eat seeds. And any abnormal diet, for any creature, can potentially result in reproductive difficulties. Animals evolve to eat certain things, and their reproductive success is predicated on eating *those* things, and not other things.

OTOH, homo sapiens does normally have a diet much higher in animal protein than mice do, so I think this study is probably not applicable to people.

Nice way to get funding, though--attach your study to the coattails of the current buzzword diet fad.