Quote:
Originally Posted by bike2work
I think you might want to consider whether ketosis during pregnancy is a good idea. Did anyone read the comments in the link to Eades' post that I provided? Even Eades and McCleary, two prominent low carb advocates, advise against ketosis during pregnancy. Stay paleo, by all means, but carb-up a bit.
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This is a paraphrase of something I recently posted to my journal, as I have recently become pregnant and don't intend to eat carbohydrates.
I don't buy the ketosis scare during pregnancy. People like Eades and McCleary have to cover their behinds, because there haven't been studies proving the safety of it. But if you look at a fetal metabolism text, it will tell you that fetuses are naturally using ketones themselves before and immediately after birth.
This text book article says "During early pregnancy there is an increase in body fat accumulation, associated with both hyperphagia and increased lipogenesis. During late pregnancy there is an accelerated breakdown of fat depots, which plays a key role in fetal development. Besides using placental transferred fatty acids, the fetus benefits from two other products: glycerol and ketone bodies. Although glycerol crosses the placenta in small proportions, it is a preferential substrate for maternal gluconeogenesis, and maternal glucose is quantitatively the main substrate crossing the placenta. Enhanced ketogenesis under fasting conditions and the easy transfer of ketones to the fetus allow maternal ketone bodies to reach the fetus, where they can be used as fuels for oxidative metabolism as well as lipogenic substrates..."
In this study they inject pregnant rats with ketones and show that the fetuses readily use them for fuel.
Similar here with sheep.
You will see claims all over the web that ketosis is dangerous for the fetus, but you won't find evidence. I see three classes of the so-called evidence. There is evidence that if you have diabetic ketoacidosis it is not good for the fetus, but we know that you can't compare benign dietary ketosis to diabetic ketoacidosis. There is animal evidence that if you starve pregnant rats, which also produces ketosis, it is not good for the fetuses. The flaw in that reasoning should be obvious. Finally, there is one experiment where they sliced up the brains of rat fetuses and soaked them in ketones, and the brain cells survived but the slices stopped producing new brain cells. This is supposed to be evidence of ketosis causing retardation.
To counter that last one,
in this study they took embryos and soaked them in ketones which either had no effect or caused them to grow. But even more relevantly,
this study shows that pregnant pigs who are put on a ketogenic diet have fetuses with "increased fetal brain weight, protein content, and cell size."
Couple these with the fact that some cultures like the Inuit ate an all meat diet, and that we probably evolved on it, I am not concerned about it.
I understand if people don't want to risk something that doesn't have current medical support, but the fact is that people are in ketosis during pregnancy quite commonly, and they certainly were in our history. It isn't some freak consequence of a modern bizarre diet, although not being in ketosis might be.