Friday, August 28, 2009

Low carbohydrate high protein and ApoE-/- mice (2)

I'm waiting to hear about the mineral content of the high protein low carbohydrate diet used to generate arteriosclerosis in mice. Personally I feel the whole study is totally irrelevant but I'm interested because (a) it is a major achievement in its own right and (b) it is being used politically to specifically warn against low carbohydrate diets. The press release is very cleverly done, anecdote and personal testimony is, I am very well aware, powerful stuff. Just like blogging really!

OK, it's time to talk about renal disease in rats and mice. I'm afraid quite a lot of it involves "models" but, well, that's just how it goes. Much of the information here comes from this paper. I think it took Malcolm Kendrick, to whom I am greatly indebted, about 5 minutes to find it on PubMed.

We're going to talk about CKD-MBD, that is Chronic Kidney Disease-Mineral Bone Disorder. CKD-MBD has three components: 1) abnormal serum biochemistries, 2) abnormal bone remodeling, and 3) vascular calcification.

Especially interesting is the last of these three, vascular calcification.

Using acute models of renal failure, particularly the 5/6ths nephrectomy, it is very very hard to demonstrate arterial calcification within the the lifetime of the animal unless you include a genetic modification, typically apoE-/- or LDLR-/- knockouts. So, if you wish to get calcification of arteries, choose an apoE-/- mouse as it speeds up the process. Adding a high content of phosphorus to the diet is also normal as this accelerates the kidney failure and is a known trigger for the conversion of a smooth muscle cell in to an osteoblast.

The phosphorus in the diet has to be bioavailable. That provided by grains is mostly there as phytic acid and, although rodents do have a phytase (humans don't), the amount of phosphate absorbed from grain based diets is much lower than from casein based diets.

In the face of early renal damage it seems like 0.7% phosphate in a casein diet (0.7g/100g) progresses the renal failure where as 0.2% keeps renal damaged animals similar to controls for many weeks. The control groups being given non bioavailable phosphate from grains.

So the next question you have to ask is whether rats or mice on lab chow have renal damage. Well, I blogged about that here.

Enough to say that nephrocalcinosis was absolutely routine until the NTP-2000 diet was introduced. This improved diet still does this:

"The NTP-2000 diet prevented nephrocalcinosis and decreased the severity of nephropathy and cardiomyopathy, the common lesions of F344 rats in 13-week studies"

Note the time scale for nephropathy. Less than 13 weeks. And this is a grain based diet with its phosphate mostly inaccessible to the rat/mouse. Whether you could get changes in the week between weaning and starting on a specialist diet is an interesting point.

But a casein based diet will allow phosphate uptake far better than a grain based diet. Two question then come to mind. Normal rat/mouse chow usually runs at just under 20% of calories from casein. Does increasing this to 45% increase the phosphate uptake? I don't know.

And perhaps you would still need to add supplementary phosphorus? Again I don't know.

So let us summarise: Casein based diets markedly facilitate the toxic action of phosphate on mildly damaged kidneys. Renal failure causes arterial calcification. Arterial calcification will occur in apoE knockout mice with renal failure under circumstances where it is impossible to get it with normal lipid metabolism. With enough tweaks it is possible to get arteriosclerosis in mice by careful manipulation of the model.

Epithelial progenitor cells are produced in the bone marrow under the influence of erythropoietin. Erythropoietin is produced by normal kidneys but only in reduced amounts by nephrotic kidneys. Vascular damage and regeneration appear to be heavily influenced by these cells.

If you wanted to make a diet for a mouse which triggered both arterial calcification and depressed EPC numbers a reasonable stratagem might be to feed a casein based high phosphate diet. To really make things happen choose an apoE knockout mouse. A normal mouse might not oblige.

You really need to know exactly how to manipulate renal function, genetics and EPC numbers in lab mice. This might not happen by accident and would require a great deal of knowledge about renal function and arterial damage.

I think that, for the time being, we will have to await the composition of both the mineral supplement used in the diets and the phosphate content of the calcium salts used as a partial replacement for that supplement in the high protein arm of the study.

But the thought train is interesting.

I was wishing for histopath on the kidneys but, if this hypothesis is correct, all that would have come out would have been that high protein diets damage kidneys.

Peter

32 comments:

Ken said...

Arterial calcifications and increased expression of vitamin D receptor targets in mice lacking TIF1α
"Altogether, these data indicate that TIF1α normally functions to repress the vitamin D endocrine system and additionally suggest that ectopic calcifications in TIF1α−/− mice are causally related to a disturbed VDR signaling pathway. Interestingly, the fact that these metabolic disturbances correlate with a calcifying arteriopathy and other features of premature aging in TIF1α−/− mice provides support for the hypothesis that aging is promoted by an increased activity of the vitamin D signaling pathway"

Stan Bleszynski said...

Quote: "You really need to know exactly how to manipulate renal function, genetics and EPC numbers in lab mice. This might not happen by accident and would require a great deal of knowledge about renal function and arterial damage."

Fascinating! Could that be a "smoking gun" evidence that we are dealing with the skilled falsifiers who rigged the test to obscure rather than find out the truth?

Who is this guy Rosenzweig?

Stan

water said...

would this be an ok time to ask about a homemade/raw diet for a 20 year old male cat with kidney issues? He only went grain-free about 9 months ago and his health really improved at that point.

He's always been completely indoors and the windows are tinted to block UVA and B, prevent heat gain, etc.

He's been eating a chicken/butter/pumpkin concoction, but I'd like to go lower phosphorus if possible. He won't eat egg whites, but I will try egg white powder next.

Any suggestions for low-Phos. and does he need any vitamin D?

Bris said...
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Bris said...

Editorial Review

Why Do Dialysis Patients Develop a
Heart of Stone and Bone of China?

Blood Purification 2005;23:203–210

Free full text:

http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowPDF&ArtikelNr=84890&Ausgabe=230762&ProduktNr=223997&filename=84890.pdf

Bris said...
This comment has been removed by the author.
Bris said...
This comment has been removed by the author.
Bris said...
This comment has been removed by the author.
Bris said...

water:

FEEDING YOUR CAT: KNOW THE BASICS OF FELINE NUTRITION

Lisa A. Pierson, DVM

http://www.catinfo.org/

homertobias said...

Peter
Do you ever worry about the casein content of the heavy cream you consume? Do you limit your casein intake in any way? Subclinical renal disease is often present in humans over 50 especially if they have a touch of hypertention or worse metabolic syndrome. Casein structurally resembles gluten and may have the same opiod receptor response. Please disentangle this one for me.

homertobias said...

Casein just continues to trouble me. Human breast milk protein content is approximately 20% casein, cow milk protein 80%. Big difference. And I am not a calf. Perhaps there is something about raising cattle for continuous milk production which boosts the casein percentage in their milk.
Does anyone know the casein percentage in Masai cattle?
I don't like tight junction destroyers (gluten,casein) nor phosphorous donors, (ditto) and support tight junction maintainers (Vitamin D).
So the Masai have some atherosclerosis on autopsey but do not have heart attacks. Hmmmmm. But their cattle are probably A2.
All conjecture here.

David said...

Masai drink A2 milk. The 1970 autopsies (before their dietary shift and subsequent autopsies a couple years later) actually found very little atherosclerosis.

We're probably in a different boat, however, since our milk us almost all A1.

JohnN said...

"Personally I feel the whole study is totally irrelevant..."

I agree with this. There's a lot we don't know about Apo-E deficiency, especially in mice.

PMID 14553825 reports some paradoxical (read opposite) effects on obese vs lean and control Apo-E-/- mice with respect to atherosclerosis.

In defense of cream: when milk is separated into two parts: skim milk and cream most if not all of the proteins (including casein whether A1 or A2) go with the former. Fermented cream is a different beast altogether; you'll have lactic acid acting as signaling molecules - usually available only to carb-consuming athletes operating above the anaerobic threshold.
John

Bris said...

David:

"We're probably in a different boat, however, since our milk us almost all A1."

The Masai drink mostly fermented milk - they have no refrigerators. Fermentation denatures the casein and whey proteins.

The Masai walk 25km each day.

I tend to agree with Malcolm Kendrick that diet isn't very important as long as sufficient basic nutrients are obtained.

Bris said...

Homertobias:
"Casein just continues to trouble me. Human breast milk protein content is approximately 20% casein, cow milk protein 80%.'

Human and bovine milk proteins are quite different. Calves also produce chymosin (rennet) which coagulates the casein to make a cheese like substance.

IMHO the only dairy foods that should be eaten are cheese and boiled milk in small quantities.

The overall health status of the Masai has probably been considerably exaggerated by many commentators. Heart disease is just one possible cause of death. All that really matters is All Causes Mortality.

Ben said...

I think you might like this:

http://zs1.smbc-comics.com/comics/20090830.gif

homertobias said...

Stan,
Dr. Anthony Rosenzweig, at the Beth Israel hospital in boston was doing low carb himself. Over lunch, Dr Shi Yin Fu was making fun of his eating style. She commented that she had alot of patients doing the low carb life style who were having CV events. So the mouse experiment was born. (Per the heart.org commentator)

Dr. B G said...

Peter,

Thank you for unravelling the Apo E -/- mystery!

You only drink cultured cream (creme fraiche) correct? I tried Trader Joe's creme fraiche in my coffee but it was too tangy. (I've gone black now.)


The Masai and other travelling nomads (like the Northern Chinese, Mongols, etc) drink raw or fermented (kefir) goat milk which is A2 casein like human milk. Goats are portable and can be kept near their tents. If at some stage of the Masai's lives, they are consuming a lot of cow milk and high carbs perhaps this triggers the atherosclerotic process?? Which then reverses during ketotic warrior 'training' consuming meat, milk, and blood?

-G

Stan (Heretic) said...

homertobias,

This is interesting! It is hard to get CV event other than arrhythmia on low carb and high fat because blood pressure improves straight away, blood clotting goes down and ketone bodies go up. All those are protective factors. I am curious about that researcher. I can recognize an honest mistake and it doesn't look like that. I think I can recognize stupidity if it were the case but this seems to be different.
Stan

Peter said...

Stan, it's not looking like the mineral content of the diet is going to be forthcoming. I asked for this information a week ago now. My wife is a scientist and very defensive about this sort of garbage being described as science! The control group diet is totally different from the intervention groups, in virtually every way it can be. The mineral composition is not described and the mineral content is specifically altered in the "interesting" intervention group. Talk about manipulating your variables. But I don't think we will get the information...

Hi water, looks like Bris has suggested a very reasonable site, despite the stupid ideas about calories out (make your cat chase a toy on a string to aid weight loss.... duh), but generally excellent. Human low phosphate diets allow meat, just not burgers with added phosphate! Jenny did a post on this, colas and paracetamol are what kill your kidneys, oh and hyperglycaemia too of course.

Homer T, not really, the amount of casein is low in cream and relatively little gets through the digestive process in tact if you are not on antacids... Pepsin breaks most of it down. And also re Rosenzweig, one has to be careful not to confuse news paper accounts with reality! If the study is junk, what should we think about its originators and their drive to do some "science"?

Yes Ben, I enjoyed it a lot!

G, I'd just love to know how they did it...

Stan, yes, an honest mistake seems unlikely. There is no explanation as to why they manipulated the mineral contents or even admission that they did, outside the table of composition. But then, why put it in the methods table at all if it makes the whole study look suspect? Surely this smack of stupidity compounding duplicity?

Peter

Dr. B G said...

*haa* I do appreciate all of Stephan's posts on the Masai -- it is illuminating to say the least!

If the Masai drank a lot of raw or cultured goat milk during the 'regression' periods, it didn't hurt. I have several patients who drink goat milk growing here in the valleys in Northern Cal 40 - 60 yrs ago(before it was unprofitable). One drank it for asthma (it worked he said and he's now in his 70s though still on inhalers). The milk has:
--rich in taurine which helps the immune system
--rich in caprylic and lauric acids and other medium chain saturated fatty acids which promote ketosis whether carbs are consumed or not

HHhhm... (but the taste is raunch!!)

-G

David said...

Goat milk can actually taste really great. I used to get some from a local goat farmer, and they said the trick to not having that "goaty" taste is to chill it as soon as possible. They would even keep their milking pails in the fridge between milkings so that the milk would be cooled as soon as it came out. I'm certainly no expert-- that's just what they told me -- but it sure tasted great every time. It's richer tasting than cow's milk, and never tasted funny in the least.

gallier2 said...

Here in France we get sheep milk joghurts and I have to say that they are really the best joghurt one can have. They have at least 5.5% fat.

Dr. B G said...

I've tried goat milk ice cream too... *bletch* maybe if I keep trying my taste buds may change!

I can't get over taurine though. Taurine is amazing stuff -- perhaps we are more feline than we think? If I take too much (like a handful) I get dizzy because my BP is 80s/50s (yes. I am alive).

Taurine has really helped a LOT of my migraineurs, in fact I'd say gluten-free, omega-3, vit D, low carb and taurine has obliterated all migraines in nearly 100% of individuals. I dunno why, but somehow it works.

David said...

G, you remember awhile back Dr. Eades talked about a book by a friend of his called The Brain Trust Program? Well in that book, Dr. McCleary talks about a "migraine cocktail," and it includes taurine. Check out this link where he talks a bit about it. He says (in reference to taurine) that it works by means of decreasing "over-activity and excessive firing of neurons."

http://somebodyhealme.dianalee.net/2008/07/q-dr-mclearys-anti-migraine-cocktail.html

Dr. B G said...

David,
You're so KNOWLEDGEABLE. That is one book I'm going to order RIGHT NOW. I keep recommending it to people but I had no idea taurine came up? I read Dr. McCleary's blog but don't recall him mentioning taurine there (though I'm a year behind)? I'm a dolt... the whole migraine thing I do is just... raw pastured goat milk.... *haa*

Anna said...

Water,

I put my 9 yo cat with Chronic Renal Failure on a homemade raw diet that was essentially the same as the one on the site recommended by Bris (I used the similar www.catnutrition.org recipe, but I'm quite familiar with the Pierson site and have corresponded with her). Within a week my "prematurely old" cat was chasing his tail!

On the rare occasions I fell behind in my cat food making and fed him grain-free canned food for a few days (supposedly high quality "human-grade" ingredients) he would start to hobble and come down stairs with an arthritic gait. Teh hobbling went away once he was back on real food. He never did regain his ability to jump high again, though.

Eventually, he did start to decline again, became despite the raw homemade food. But he never needed any meds (and I rejected the vet's recommendation for Rx low protein high carb kibble). We had three years with him on the raw homemade diet before he became acutely sick. We had him put down last November when he was 12.5 yrs. I feel quite sure his final years were far better on the homemade raw food than they would have been on medication, constant vet visits, and eating Rx kibble.

Our younger cat is thriving on the raw homemade food. She was probably 2-3 years old and eating Iams kibble at the animal center when we adopted her. I immediately put her on grain-free canned food that first year. Then when the olde cat was diagnosed with CRF I bit the bullet and began making their food. I'm hoping with her we're avoiding the damage that the kibble caused in the older cat.

Good luck with your cat.

Pekka Pessi said...

Peter,

If you compare Teklad's protein adjusted diets, you can see that they have 13,4 g of TD.79055 Ca-P-deficient mineral mix but the amount calcium carbonate and calcium phosphate vary with the casein content. "Custom" LCHP chow has slightly less calcium salts than 40 E-% protein chow.

I'd guess that the LCHP chow contains same amount of calcium and phosphorus as the protein adjusted chows (0,7 % Ca, 0,54 % P). The SD has 1,0 % Ca, and 0,65 % P. And it looks like WD has 2,6 % Ca (!) and 0,65 % P.

But of course your guess is as good as mine, and I find it a bit strange that they don't show the full details even in the supplement.

Peter said...

Pekka,

It's all guesswork when the methods are so badly written. Try submitting something like this to a science journal and see what the scrutineers say about your methods section. I believe you are supposed to be able to replicate the study!

Peter

Healthy Womens said...

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water said...

Thank you with the cat diet advice. Our cat died this week, at 20.5 years, having had kidney problems for at least 1/3 of his life. This last year he was on a no grains diet for the most part. He got a little picky during a round of antibiotics for a UTI so we fed more randomly. He was pretty comfortable until the end (a bit arthritic)and I think the diet made a difference. I was never certain about vitamins, phosphorus and all that, but the vet was impressed with the resilience of his skin. She said it was like an outdoors cat. She found his overall condition, for his age, to be pretty remarkable; but I didn't get very far discussing diet.

Peter said...

Hi Water,

Sorry you lost him. I'd agree, a respectable age, but that doesn't help much at the time...

Peter