Friday, July 8, 2011

Rats, Poison, and Sugar

Lucas Tafur has a fascinating post.  Read the whole thing.

But first, a couple of definitions.

A ketogenic diet (KD) is a low-carbohydrate, low-protein diet [Update 11/11/2015: this is what I understood at the time. I've since learned low-protein is not necessary, or even beneficial, except in some particular case, like diabetic kidney failure]. The body gets its energy from ketones, which are created from fat, and directly from fat, with a little bit from glucose created from protein in the liver.

LD50 is lethal dose, 50% fatality.  It's a dose of a poison calibrated to only kill 50% of the animals to which it's given.

"Soman is an extremely toxic substance which inhibits cholinesterase activity, having profound effects on the [Central Nervous System]. Increased exposure can ultimately lead to death. Langston and Myers (6) tested the influence of diet on soman toxicity in rats. For this purpose, rats were fed four different diets: standard (SD), choline-enriched (CH), glucose-enriched (GL) and a ketogenic diet (KD). The doses used in this study were 0.4-0.5 of the acute 24-h LD50. This dosing regimen was chosen to induce significant cumulative toxicity that would permit characterizing differences in the rate of onset of soman toxicity, the degree of toxicity, and the rate/degree of recovery from soman toxicity as a function of diet composition."
This is your rat on glucose.

So they want to study the effect the different diets have on the rats' ability to cope with the poison.  Turns out the effect is significant.

"Specifically, all KD animals survived a cumulative 5.0 LD50 dose of soman, whereas all glucose animals died following a cumulative 3.2 LD50 dose of soman. Not only was survival enhanced in KD animals, but there were also minimal differences in body weights compared to dietary controls injected with saline. Furthermore, KD animals exposed to soman exhibited few performance decrements on an avoidance task, and there were fewer instances of behavioral incapacitation in KD animals compared to the other diet groups."

So poison + glucose = death. Poison + ketogenic diet = immunity. That's pretty fascinating.

Makes you think glucose might be over-rated.