Tuesday, September 15, 2009

NAFLD model based on fish oil

Just briefly, another post on NAFLD, in frivolity:

"We fed a highly unsaturated fat diet (30% fish oil) to female Sprague-Dawley rats (180-200g), consumed ad libitum for 8 weeks"

"We propose that female rats fed with a diet containing highly unsaturated fatty acids are an extremely useful model for the study of NAFLD"

I propose this is bullsh*t.

If you are on 3000kcal/d and are going to drink 100ml/day of fish oil as 30% of those calories, PLEASE do not make up the rest of your non protein calories from dextrose. I warned you.

Also, if you think this in any way represent the human NAFLD which is rampant in the developed world, please desist from this idiotic idea and send your funding money to me, preferably in used fivers. And go clean that toilet.



Don Matesz said...

I second your proposal.

Nickle said...

Although using any primarily vegetarian animal as a model for dietary fat studies is bullsh*t I’ve always thought that rats were a particularly bad choice given that they have no gall bladder. As they are therefore unable to store and concentrate bile wouldn’t that severely impact their ability to digest long-chain fats? Whilst this may not impact metabolism directly the excess fat passing through the gut will surely affect digestion in other ways and have an impact upon the gut flora. Or is this over simplifying things?

Peter said...

Hi Nickle,

Just flitting through a few self selection papers, rats seem to choose between 20 and 35% calories from fat if given free choice. This can rise to 60-70% if they are allowed to treat their own (drug induced) diabetes. But I guess they might be nibblers, so not need a sudden surge of bile the way a cat, dog or human might. But mice do have a gall bladder........ Hmmmmm


Theo Tiefwald said...

I just found your blog...really GREAT stuff -- thank you so much for your work here.

Since I'm new around these parts, I'm not sure if you caught the following study:

"Deterioration of physical performance and cognitive function in rats with short-term high-fat feeding" - http://www.fasebj.org/cgi/content/abstract/fj.09-139691v1

More lies about a high-fat diet making people stupid. They say:

"In addition, a high-fat diet over several months leads to cognitive impairment."

Peter said...


I never really discussed Murray's paper as it doesn't specify the diet used and he won't reply to a very polite email requesting the formula.

But perhaps it is all true and the fact that I have a BMI of 21, keep walking up mountains and paddling down rivers are all figments of my demented, I mean cognitively impaired, few remaining brain cells.

Ultimately all of this does come down to semantics, a high fat diet, based around sucrose, really is bad news. A high fat diet verging on ketosis has nothing in common with one based on sucrose and is what I call a genuine high fat diet and is good in humans and rats.

My problem with "high fat" (sucrose based) diets is that people extrapolate this to say all fat is bad. No, fat in the presence of sucrose is bad. Near ketogenic is very different.


Nick said...


I am curious about your take on ketosis. You mention 'near ketogenic' diet here and indicate that near ketogenic is your usually eating pattern. I switched to LC and then grain free about six months ago (a response to possible insulin resistance and then watching my allergies disappear).

I have noticed that on a whole food, grain free diet I have slipped into a ketogenic state and though I see claims that this can have benefits, I am curious about your take, particularly knowing that you choose 'near ketogenic'.

Peter said...

Hi Nick, This question comes up so often I'll see if I can get around to putting a post up about it or update the "my details section". Actually I need to tidy up the whole blog and put in a links section and....


Summary: Raises cortisol, raises sympathetic tone, catabolises protein and I only eat protein to just above my needs, elegance (why convert protein to glucose when you can eat chips?????)... Some ketones are fine. I seem to be in ketosis quite a lot at the moment, exercise does that unless you significantly up the carbs...

Nick said...

Hi Peter, thank you for your comments on ketosis. Reading other posts, I see that you are okay with starch because you can tolerate it. I'm still not sure what causes my muscle and joint pain, but it seems to come and go. It is much better than it was before I went LC and grain free about eight months ago. As far as I can tell, it must be caused by wine and/or dairy as I have eliminated just about everything else. I can't seem to track the pattern.

BTW, all my siblings have GI, arthritis, allergy and thyroid issues.

Thank you for the summary, I'm sure many others would enjoy a post with more detail about ketosis. I haven't tried to go into ketosis, but can smell it in my urine for the past few months. I want nothing to do with protein catabolism given that my reason for starting LC was due to finding out I was prediabetic, so would like to increase lean mass. Sympathetic tone is interesting to think about also, given it's connection with both lower back (does chronic back pain or inflammation have an effect on SNS?) and heart rate regulation.


Anonymous said...

Repeat after me



your brush is over there . . .

altavista said...

Took an abdominal ultrasound for a pulled muscle in the rib cage and got this:

"The liver is increased in echogenicity and mildly heterogeneous in echotexture, in keeping with fatty change. No focal lesion is identified. Diffuse increase in hepatic parenchymal echogenicity likely indicative of underlying hepatic steatosis."

Could it be the nuts? Or it's just bland CYA diagnostic since 70% of the population have NAFLD?

Peter said...

Would it be straightforward to get a second opinion?


altavista said...

Will find a different clinic, but blood tests first. It's strange, with HOMA-IR at 0.73 and trigs 1.6 mmol.

Could be fat overload. It's alot easier to overdose on fresh cream than on butter/fatty meat and I spike my ice cream with cream when I'm eating. Then I hit the loo in 30 minutes lol

Peter said...

Have you picked up on some of the carnivore discussions that "fasting" trigs of several hundred can be left over chylomicrons from last night's kilos of steak. Waiting significantly more than 12 hours gets them to much more normal...... Nice HOMA IR!