I had just this moment be reading this
https://chrismasterjohnphd.com/2010/11/23/sweet-truth-about-liver-and-egg-yolks/
Which shows the importance of know more than just what the study is investigation otherwise the results can be very misleading.
Part of the article
"These experiments were back in the day, before researchers realized that methionine would be able to indirectly cure choline deficiency. Another group of researchers had the bright idea of trying to replicate this experiment in a group of rats who were consuming sufficient protein to maximize growth. So they fed them 40% beef drippings but replaced another 20% of their cereal grains with the milk protein casein.
Lo and behold, these researchers discovered a now well known phenomenon that occurs during the process of scientific discovery called the “epic fail” (13).
All of the groups had average levels of liver fat under 7% and could hardly be said to have gotten fatty liver of any sort.
So the researchers had an idea. Perhaps it was the casein they fed them that was the problem. And indeed, their hypothesis turned out to be correct: on a choline-free, 40% beef dripping diet, reducing the casein from 20% to 5% doubled the level of fat in the liver (14).
Those of you who have been reading my blog for the past few months may remember that in the wake of Denise Minger’s shredding apart of the China Study’s epidemiological data, I dug deep down into the buried secrets of Dr. T. Colin Campbell’s rat research, and found that he attributed the “protective” effect of 5% casein diets to the massive fatty liver that the rats developed. As described in “The Curious Case of Campbell’s Rats” and the associated addendum, the membrane containing a drug-detoxifying enzyme that he blamed for liver cancer got stuffed with 3-4 times more fat, which may have clogged up the enzyme and stopped it from working. Well, it turns out that others had shown a similar effect of such a diet on liver fat decades earlier.
Back to the 1930s. So these researchers repeated their experiment with the different fats, this time using 5% casein. Ta-da! The experiment worked much better (13):
The butter produced the worst fat accumulation, where almost a third of the liver was fat! The animals taking cod liver oil tended to eat a bit less food than the others, which undoubtedly confounded the results at least to some degree, but it still seems from this graph that the more saturated the fat and the longer-chain the fat, the worse the fatty liver was. In fact, if we blow up the graph, we can see this more easily:
Whoa! Hold your horses, you might be thinking. Mr. Masterjohn, haven’t you been telling us that saturated fat protects against fatty liver disease?
Well, yes I have, and I stand by that. But it appears that things are a little more nuanced than they first appeared. As it turns out, saturated fats increase the choline requirement a bit more than PUFAs do. Take a look at the results of this 1957 paper that tested the effect of butter and corn oil on the choline requirement (15):
As it turns out, the choline requirement is about 30% higher on a 30% butter diet than on a 30% corn oil diet. Why would this be? It’s not entirely clear, but I have a good guess. As I pointed out in my PUFA Report, “How Essential Are the Essential Fatty Acids?”, studies in rats, humans, and other primates show that 18-carbon PUFA are burned for energy at an extraordinarily high rate compared to other fats. In rats, 60% are burned for energy, 20% are broken down into basic building blocks to make more saturated fatty acids, and most of the rest are secreted into the fur. They do accumulate over time at a slow rate, but the body seems to sense that these fatty acids are an unnecessary oxidative liability and tries to get rid of them however it can. Thus, perhaps saturated fats require more choline to get them out of the liver because they don’t scare the liver into burning them for energy so quickly.
In any case, the clear picture that is emerging is that dietary fat increases the choline requirement, and that high-fat diets promote fatty liver only when the level of choline in the diet is insufficient to meet the extra demand for it caused by the increase in fat."
Don;t know how to get the images to display but they are very clear.
https://chrismasterjohnphd.com/2010/11/23/sweet-truth-about-liver-and-egg-yolks/
Which shows the importance of know more than just what the study is investigation otherwise the results can be very misleading.
Part of the article
"These experiments were back in the day, before researchers realized that methionine would be able to indirectly cure choline deficiency. Another group of researchers had the bright idea of trying to replicate this experiment in a group of rats who were consuming sufficient protein to maximize growth. So they fed them 40% beef drippings but replaced another 20% of their cereal grains with the milk protein casein.
Lo and behold, these researchers discovered a now well known phenomenon that occurs during the process of scientific discovery called the “epic fail” (13).
So the researchers had an idea. Perhaps it was the casein they fed them that was the problem. And indeed, their hypothesis turned out to be correct: on a choline-free, 40% beef dripping diet, reducing the casein from 20% to 5% doubled the level of fat in the liver (14).
Those of you who have been reading my blog for the past few months may remember that in the wake of Denise Minger’s shredding apart of the China Study’s epidemiological data, I dug deep down into the buried secrets of Dr. T. Colin Campbell’s rat research, and found that he attributed the “protective” effect of 5% casein diets to the massive fatty liver that the rats developed. As described in “The Curious Case of Campbell’s Rats” and the associated addendum, the membrane containing a drug-detoxifying enzyme that he blamed for liver cancer got stuffed with 3-4 times more fat, which may have clogged up the enzyme and stopped it from working. Well, it turns out that others had shown a similar effect of such a diet on liver fat decades earlier.
Back to the 1930s. So these researchers repeated their experiment with the different fats, this time using 5% casein. Ta-da! The experiment worked much better (13):
Whoa! Hold your horses, you might be thinking. Mr. Masterjohn, haven’t you been telling us that saturated fat protects against fatty liver disease?
Well, yes I have, and I stand by that. But it appears that things are a little more nuanced than they first appeared. As it turns out, saturated fats increase the choline requirement a bit more than PUFAs do. Take a look at the results of this 1957 paper that tested the effect of butter and corn oil on the choline requirement (15):
In any case, the clear picture that is emerging is that dietary fat increases the choline requirement, and that high-fat diets promote fatty liver only when the level of choline in the diet is insufficient to meet the extra demand for it caused by the increase in fat."
Don;t know how to get the images to display but they are very clear.