High-Protein Diets Increase Risk of Developing Kidney Disease in Rats, Study Suggests

[Demi]

Here we go again with those exploding kidneys! :rolleyes:


From Science Daily
January 21, 2014

High-Protein Diets, Like the Popular Dr. Dukan Diet, Increase the Risk of Developing Kidney Disease in Rats, Study Suggests

An experiment done in rats by scientists at the University of Granada, Spain, shows a high-protein diet increases the chance of developing kidney stones and other renal diseases.

High-protein diets, like the popular Dr. Dukan diet, increase the long-term risk of developing kidney disease and have a negative effect on renal urinary and morphological markers, the study suggests. What's more, they may promote serious pathologies like nephrolithiasis (calcium kidney stones) because they drastically reduce urinary citrate (an inhibitor of calcium salt crystallization) and urinary pH, and increase urinary calcium (to compensate for the metabolic acidity caused by excess protein).

University of Granada scientists have demonstrated this in an experiment in rats that examined the effects of a high-protein diet on renal urinary, plasma and morphological parameters.

The researchers studied 20 Wistar rats, divided into two groups of 10. The first group were fed a high-protein diet of commercial hydrolysed protein supplements with a 45% protein level. The control group were fed a normal protein diet. The experiment lasted 12 weeks, which is the equivalent of 9 years in human terms.

10 per cent weight loss

The results showed that the rats on a high-protein diet lost up to 10% of their body weight over the 12 weeks with no improvement in their plasma lipid profile. Moreover, urinary citrate in these rats was 88% lower and urinary pH was 15% more acidic. In the animals fed a high-protein diet, kidney weight increased by 22%, glomerular area -- the network of capillaries that filter blood in the kidneys -- by 13%, and the mesangium -- a collagen structure surrounded by these capillaries -- by 32%.

The results of this study lead the principle author, Dr Virginia A. Aparicio of the University of Granada Department of Physiology, to stress the need to closely monitor anyone on a high-protein diet. The Dukan diet, and others like it, may have serious long-term adverse effects on their health, if the rat study results are applicable to humans.

She warns that the negative effects of high-protein diets on the kidney also depend on the presence of other nutrients in the diet. "Eating large amounts of fruit and vegetables reduces the risk of kidney stones forming -- probably due to their high potassium and magnesium content, which compensates for the acidity of the high-protein diet," Dr Aparicio concludes.

Journal Reference:
Aparicio VA, Nebot E, García-del Moral R, Machado-Vílchez M, Porres JM, Sánchez C, Aranda P. High-protein diets and renal status in rats. Nutr Hosp., 2013 Jan-Feb;28(1):232-7 DOI: 10.3305/nh.2013.28.1.6165 (http://dx.doi.org/10.3305/nh.2013.28.1.6165) http://www.sciencedaily.com/releases/2014/01/140121093006.htm

[leemack]

Good, now at least rats know not to eat a 45% protein diet! I certainly don't know any humans who do.

[Elizellen]

I was looking for that cartoon "Oh Noes, my kidney asploded" to post here but could only find this in the definitions in the fool wiki
Kidney a splosions

Most commonly found in people who have been doing the Atkins diet for several years. The weakened kidneys reach a critical state where they a splode abruptly. It's not uncommon to hear a low-carber utter the words "my kidneys a splode!" Despite their a sploded kidneys, they do not die and continue ambling about as lively as ever, much to the frustration of medical experts.http://www.thefoolwiki.org/Asplode

[M Levac]

Phew! Good thing we're not rats.
The results of this study lead the principle author, Dr Virginia A. Aparicio of the University of Granada Department of Physiology, to stress the need to closely monitor anyone on a high-protein diet. The Dukan diet, and others like it, may have serious long-term adverse effects on their health, if the rat study results are applicable to humans.
And that leads this reader to stress the need to closely monitor lead researchers who draw such naive conclusions. Where is the human experiment to see if indeed any of this applies to humans? But wait:
The experiment lasted 12 weeks, which is the equivalent of 9 years in human terms.
There is no human experiment like this. Furthermore, this equivalency premise is flawed, since protein intake was proportional, not absolute, therefore if a human should eat 45% protein, he too would see an effect after only 12 weeks, if any effect was to be seen. As it happens, there is at least one similar experiment from which we can extrapolate the potential effects of "high-protein" diets; The Bellevue All-Meat trial. It lasted 1 year, 4x times longer than that rat experiment. No adverse effect was seen from eating all that meat. However, there were adverse effects from eating lean meat after only a few days (which were corrected by eating fat meat, also after only a few days), and from the glucose tolerance tests (which too disappeared quickly once the all-meat diet was resumed).

Rats!

[rightnow]

She warns that the negative effects of high-protein diets on the kidney also depend on the presence of other nutrients in the diet.
Every diet depends on what is in the diet. Of course. If 45% was protein, what was the other 55%?

45% protein is too high anyway. No popular diet plans recommend 45% protein, so why test something they don't recommend and then advertise it widely as if any diet associated with more protein than the SAD is dangerous? For the same reason they tested Atkins diet with twice the number of carbs and then advertised it didn't work as he claimed. For the same reason there are regularly media shows warning of the great danger of protein.

If your body is screwed up it might not handle protein well because protein, the amino acid building blocks of much of your tissues, takes actual work on the part of the organs to process. It's well worth the effort. But if your organs are already screwed up, and then you do a massive emphasis on organ-heavy foods, yes it can cause issues. This is not an issue of protein, of which man is utterly dependent, and has been since the dawn of time. It's an issue of screwing up your organs with bad foods, toxins and pharmaceuticals for a lifetime, then eating a lousy diet, to include more protein than by that time your struggling organs are up to, and eventually yes it may be a problem. It has nothing to do with the GOOD food one is eating, but with everything else.

When I first did Atkins (actually I was doing Protein Power) my parents warned me with wide eyes that they had just watched a 20/20 special on how dangerous "high protein diets like Atkins" could be.

Me: Really. So how much protein should a person get by bodyweight?

Them: Um.

Me: How much protein does the Atkins diet recommend compared to that?

Them: Um.

Me: So in fact you have no idea how much protein it recommends or how much protein a person should get. But based on this TV show you are sure it is dangerous.

The media across the board is part of the corporate oligarchy which as a loose but seemingly intentional pattern, farms humans into chronic poor health as a consumer status.

PJ

[Turtle2003]

Guess I have to email my grandchildren right away and tell them not to feed their pet rats a diet of commercial hydrolysed protein supplements with a 45% protein level.

[teaser]

fed a high-protein diet of commercial hydrolysed protein supplements with a 45% protein level.

She warns that the negative effects of high-protein diets on the kidney also depend on the presence of other nutrients in the diet. "Eating large amounts of fruit and vegetables reduces the risk of kidney stones forming -- probably due to their high potassium and magnesium content, which compensates for the acidity of the high-protein diet," Dr Aparicio concludes.

I think potassium is one of the few nutrients where the recommended daily amount is based on how many fruits and vegetables "they" hope we'll eat, rather than actual requirements for health.

Meat has fair amounts of potassium, as long as you don't cook it out. And some magnesium as well. Hydrolysed proteins have none. This study might apply to highly refined proteins. Just like with highly refined carbohydrate, this stuff gets digested quickly, and there'll be a larger and more acute elevation in serum amino acids, and that's a load that both the liver and the kidneys will have to deal with. Those amino's should be absorbed slowly, and absorbed with other nutrients that come with the meat. I do use whey protein, but I feel guilty when I'm eating it. :lol:

I'm not sure even these rats would have any trouble with healthy whole proteins.

[Liz53]

I'm not sure even these rats would have any trouble with healthy whole proteins.

And if they were allowed to eat normal whole proteins ad libitum would they even choose to eat that much protein? Probably not. These are rats in a cage with one option of what to eat or else they starve.

[Nancy LC]

http://2.bp.blogspot.com/_U-TCLgocY9I/RzNyqt36afI/AAAAAAAAAD4/yRSpl2b52yQ/s320/Asploded.jpg
I think this might become my new avatar!

[Zei]

I tried the Dr. Dukan diet once for just a day out of curiosity. Just one day because I quickly found it while fairly low carb was much too high in protein and low in fat for me. If you cut both the fat and carbs from your diet leaving not much else but protein for calories you can get pretty sick. Like those Bellevue guys did until they ate meat with enough fat.

[jmh]

I've just bought some high quality 'complete' food for my dog. It is designed to replicate their natural diet. It is made up of 80% animal products which gives 38% crude protein and 18% crude fat.

Will my dog's kidneyz a splode? :lol:

[Liz53]

Will my dog's kidneyz a splode? :lol:

If they do, I hope you will post pictures. :D

[Ann_LC]

Interesting. My 17 yr old cat was in kidney failure for a year and due to his heart issues, could not take fluid. We lowered his protein levels in food, as per vets (regular and specialist) recommendations. His numbers kept getting worse. Then my vet told us that there is a school of thought that said do the opposite, feed more protein - so we did, since we had to try something. After 2 months of a high protein diet, my cat's kidney levels are now normal.

[rightnow]

Wow, thanks for that report Ann.

Much of medicine could probably work that way. "Or do the opposite of what the experts say..."

PJ

[teaser]

http://www.pnas.org/content/83/15/5659.full.pdf

ABSTRACT Autoimmunity-prone (NZB x NZW)F1 (B/W) female mice are used as a model of human lupus erythematosus. When full-fed, these mice die of glomerulonephritis between 7 and 11 (average 9) months of age. When food intake is restricted to 60% of calories, the onset of this disease
is delayed and the mice live greatly prolonged lives free of disease. Since high protein intake is commonly associated with acceleration of kidney damage in humans and experimental animals, the current experiments were designed to employ diets in which protein concentration was as high as possible. The observations demonstrate clearly that with this model of
autoimmune disease, total calorie intake (from whatever source) exerts an overriding influence on life span. A higher calorie intake leads to early death and restricted-calorie intake leads to an increased life span. When B/W mice are full-fed, with respect to calories, feeding diets of greatly differing
protein composition did not influence life span significantly. By contrast, calorie restriction of diets, even of very high protein content or of lower protein content, greatly prolonged life of B/W mice. Even with exceedingly high protein intake (>83% of the calories) it is not protein per se but the total calorie intake that exerts the greatest influence that determines length of life in mice of this autoimmunity- and glomerulonephritis-prone
strain.


In this study, mice bred so that the main cause of death is kidney disease are fed low-protein, high protein, low-protein calorie restricted and high protein calorie restricted. No difference at all between high protein and low protein without calorie restriction. The calorie restricted low protein group lived three times as long, calorie restricted high protein twice as long.

All the calorie restriction in the high protein mice came from removing sucrose from the diet. Also most in the low protein mice. A surprising number of calorie restriction, methionine restriction etc. studies use sucrose as the carbohydrate. In one study, rats were fed ad lib with glucose or fructose as the carb source, or calorie restricted with glucose or fructose as the carb source. There was no benefit to restricting glucose in that study. The longest living group were the rats fed fructose, but calorie-restricted. My bias tells me that if calories are restricted so that the damage fructose causes to the liver is prevented, the fact that fructose, unlike glucose, doesn't call for much of an insulin response becomes a net advantage.

What does this say, if a person eats a high protein diet--but it reduces appetite, so calories are restricted as well? Not much unless you happen to be a good model for "Autoimmunity-prone (NZB x NZW)F1 (B/W) female mice." But it's certainly something that needs to be considered.

Also, the rat study--some of the "markers" of kidney disease are just signs of increased oxidation of protein--which will go up, and have nothing to do with pathology, if dietary protein goes up.

[Liz53]

Interesting. My 17 yr old cat was in kidney failure for a year and due to his heart issues, could not take fluid. We lowered his protein levels in food, as per vets (regular and specialist) recommendations. His numbers kept getting worse. Then my vet told us that there is a school of thought that said do the opposite, feed more protein - so we did, since we had to try something. After 2 months of a high protein diet, my cat's kidney levels are now normal.

I did the exact same thing as you did with my cat. Just about 5 years ago my cat (who is now also 17) was determined to have early kidney failure. I researched it and saw the low protein diets were unpalatable to cats and I'd have to add back the grain that had given her IBS for the first 6 or 8 years of her life. I've kept her on a relatively high protein grain free diet and while her numbers have gotten somewhat worse over the 5 years, she is nowhere near dying from it. I wanted to keep my cat happy for the rest of her days no matter if they were long or short, but it turns out the diet that makes her happy is giving her a good long life as well.

I'm curious what brand you are feeding your cat? My cat's numbers are stable but maybe I could improve them?????

[Nancy LC]

I've seen studies about higher-protein diets in humans with kidney failure too (and that it helps).

I think my Siamese cat lived as long as he did, because I ignored the advice to lower his protein.

[Ann_LC]

I'm curious what brand you are feeding your cat? My cat's numbers are stable but maybe I could improve them?????

My cat eats the following:

Daily: wellness grain free canned (eats very little of this), boneless skinless chicken breast with some butter on it, tuna in water, licks butter of his toast every morning

1x/wk: baked salmon, scrambled egg (in butter)

occasionally: my husband will get him an eggroll LOL!

I agree with you - at this point in his life, I am looking for quality for him, not quantity. He's had 2 heart failures, has ibd, hypothyroid, had a urethral redirect, and some kind of skin allergy (they were never able to determine what he's allergic to) that is controlled by me rubbing some olive oil on his back - which he loves to lick off.

Since we started giving him what he will actually eat and not what we should be feeding him - his health is so much better.

Sometimes when someone will ask me what I'm having for dinner, I'll say cat food! :lol:

[Nancy LC]

Lots of cats are VERY sensitive to gluten. I've also have had some cat food give every one of my cats diarrhea (EVO turkey/chicken). I think it was just too high protein since there are no grains in it.

Cats almost never get hypothyroid. Are you sure it wasn't hyperthyroid? That is very common in cats.

[Ann_LC]

yes, yes Nancy - it is hyperthyroid

once I started feeding him mostly ppl food, he almost never gets diarrhea. I also give him taurine, since he eats so little actual cat food (buy it powdered and put in #3 gel caps).

Yeah, most cats seem to not handle grain all that great, though some are ok with it (I do foster rescue and volunteer feed at a local cat colony). It's funny, the food that seems to cause the most issues in my cats, is red meat (raw and cooked). I would go out and buy some grass fed beef for the kitties to try - but I think at this point my hubby would kill me if I did that!

[Nancy LC]

I've read that cats can become allergic or intolerant of beef very quickly. So there could be something to that, Ann.

This place has great info: http://www.catinfo.org/

[Zei]

I have a dog, not a cat. But the vet told me that while dogs do naturally eat other stuff besides meat, cats are carnivores. So it makes sense grains can make them sick. I think the grains are in commercial cat food because it's a cheap filler material, not that it's good for cats. Also cattle couldn't possibly be a type of meat a cat would naturally eat. Cows are huge. It'd take a big lion or something to take one of those guys out. Our dog is really old now and I no longer care what quality of food it is, just that she's willing to eat it and gets some calories into her, but she still does generally prefer meats.

[Ann_LC]

Our dog is really old now and I no longer care what quality of food it is, just that she's willing to eat it and gets some calories into her, but she still does generally prefer meats.

I totally agree. When someone newly adopts one of my kitties and they ask me what litter is the best - I always tell them the one the cat will use! :)

My cats do eat other things like grasshoppers (shudder!!), bugs, worms, birds ... and of course grass. The thing is, when they eat grass, it's usually because they have a hair ball that needs to come out

[leemack]

I totally agree. When someone newly adopts one of my kitties and they ask me what litter is the best - I always tell them the one the cat will use! :)

My cats do eat other things like grasshoppers (shudder!!), bugs, worms, birds ... and of course grass. The thing is, when they eat grass, it's usually because they have a hair ball that needs to come out

True. We've got two smart cats. They will only eat the high protein grain free (human quality) food that we give them, and turn their noses up at anything 'lesser' (offered by neighbour). They also eat bugs and worms. They only play with birds though, they don't bother eating them (that I've seen). They've been fed this way since 6 weeks old. They are very healthy, with soft shiny coats. Our larger cat is just over 5 kg, and the vet started making noises about him not gaining any more and diet food - but he is a huge framed cat, who isn't fat, and is all muscle. Nothing will make me swap them from the healthy proper food that I currently feed them, onto something processed.

I strongly believe that we should feed carnivores (as cats are) like carnivores, and that this is what is best for their health.

[Ann_LC]

They will only eat the high protein grain free (human quality) food that we give them, and turn their noses up at anything 'lesser' (offered by neighbour).


Whatever the cats turn their noses up at - the dog eats :lol: :lol:

It's great you've been feeding them good quality since they were young. I always end up with the unwanted cats - older, sick, behavioral problems, but I always see an improvements in them with a better diet

[leemack]

Whatever the cats turn their noses up at - the dog eats :lol: :lol:

It's great you've been feeding them good quality since they were young. I always end up with the unwanted cats - older, sick, behavioral problems, but I always see an improvements in them with a better diet

We changed our last cat on to a good diet after we adopted him, but he was older by then and ended up with kidney cancer. By the time we got him he was a complete carb addict, and when he was sick would only eat a carby pate food. We hope that by doing things right from a young age, we'll avoid a lot of health problems with our current two.

Every dog I've had would eat anything - but then dogs are omnivores - but still shouldn't be eating the carb laden rubbish and sweets that most people feed them.

Even our cat treats are 100% dehydrated meat and fish chews.

[Melissa 67]

Interesting. My 17 yr old cat was in kidney failure for a year and due to his heart issues, could not take fluid. We lowered his protein levels in food, as per vets (regular and specialist) recommendations. His numbers kept getting worse. Then my vet told us that there is a school of thought that said do the opposite, feed more protein - so we did, since we had to try something. After 2 months of a high protein diet, my cat's kidney levels are now normal.
I have a 21-year-old CRF cat. He wouldn't eat Hill's k/d at all (can you blame him?). As he was recovering from a serious illness where he wouldn't eat anything I decided, "Screw it--he can eat whatever he wants, as long as he eats." He was 19 at the time, and none of us lives forever, after all.

And what he wants is half a can of Fancy Feast at each meal, along with lots of plain, cooked beef. I chop up stew beef into bite-size chunks, simmer it until it's just done, and that's what he gets, along with lots of the broth. I also give him liver, and whatever other offal I might be eating. And as rickety as he is, he just keeps going, and his coat looks great. His kidney values aren't perfect, but they haven't declined in two years, and he's not on fluids. Not bad for an old man.

Unfortunately, that approach didn't work for his brother, who died last April of congestive heart failure (after two years on sub-qs for CRF), but his kidney disease was much further advanced, and I doubt anything I could have done would have helped.

[Ann_LC]

We changed our last cat on to a good diet after we adopted him, but he was older by then and ended up with kidney cancer. By the time we got him he was a complete carb addict, and when he was sick would only eat a carby pate food. We hope that by doing things right from a young age, we'll avoid a lot of health problems with our current two.

Every dog I've had would eat anything - but then dogs are omnivores - but still shouldn't be eating the carb laden rubbish and sweets that most people feed them.

Even our cat treats are 100% dehydrated meat and fish chews.

I'm sorry you lost your last cat due to kidney cancer. I truly believe you are doing things right with your current two. Just think how much better off all of us would be if we had eaten right from the start.

[Ann_LC]

I have a 21-year-old CRF cat. He wouldn't eat Hill's k/d at all (can you blame him?). As he was recovering from a serious illness where he wouldn't eat anything I decided, "Screw it--he can eat whatever he wants, as long as he eats." He was 19 at the time, and none of us lives forever, after all.

And what he wants is half a can of Fancy Feast at each meal, along with lots of plain, cooked beef. I chop up stew beef into bite-size chunks, simmer it until it's just done, and that's what he gets, along with lots of the broth. I also give him liver, and whatever other offal I might be eating. And as rickety as he is, he just keeps going, and his coat looks great. His kidney values aren't perfect, but they haven't declined in two years, and he's not on fluids. Not bad for an old man.

Unfortunately, that approach didn't work for his brother, who died last April of congestive heart failure (after two years on sub-qs for CRF), but his kidney disease was much further advanced, and I doubt anything I could have done would have helped.

At 21, I'd give him anything he'd want too! Cats can get fatty liver disease pretty fast if they don't eat - so if a cat's sick, they should eat whatever you can get in them.

I'm sorry for you loss last year.

[leemack]

I'm sorry you lost your last cat due to kidney cancer. I truly believe you are doing things right with your current two. Just think how much better off all of us would be if we had eaten right from the start.

:agree: If only!!!

[Liz53]

My cat eats the following:

Daily: wellness grain free canned (eats very little of this), boneless skinless chicken breast with some butter on it, tuna in water, licks butter of his toast every morning

1x/wk: baked salmon, scrambled egg (in butter)



Thanks, Ann. It sounds as if we're on the same wavelength. Amelia eats Wellness as well, but shows no interest in chicken, salmon or butter (I've tried them all). At any rate, she's thriving.

[ProfGumby]

http://2.bp.blogspot.com/_U-TCLgocY9I/RzNyqt36afI/AAAAAAAAAD4/yRSpl2b52yQ/s320/Asploded.jpg
I think this might become my new avatar!
Thanks for the laugh! I would also want to use that as an avatar... :lol:

[WereBear]

Wow, thanks for that report Ann.

Much of medicine could probably work that way. "Or do the opposite of what the experts say..."

PJ

My whole eating pattern for over ten years has been exactly that!

My own vet exclaimed over 17 1/2 year old James Bond, said he would have guessed him at five years younger, he's doing so well. But when he found out we fed him mostly canned, he got worried about the "high protein" and said we should change his food.

Oh, yeah, the food that got him this far with fur like a kitten's and the ability to still jump on and off his favorite hassock.

I don't think so.

[RawNut]

Thanks for the laugh! I would also want to use that as an avatar... :lol:

And this was her last one inspired by this story (http://forum.lowcarber.org/showthread.php?t=454343&page=1). :D:

http://farm3.staticflickr.com/2368/2242969237_8893787c8c.jpg

[Nancy LC]

LOL! Well, as you can see I've switched. Anyone remember the Bunny Thief? :) Then there was licky kitty.

[LorelaiS]

I just switched my cats to EVO (did it slowly so they didn't get sick from a drastic switch). My Siamese who is 13 and has had a stuffy nose for 3 years just came up to me and put his wet, clear nose on my arm. This is the only thing we've changed for them.

[RawNut]

Oh yes! My screen was always nice and clean when you had licky kitty.:agree:

[Bonnie OFS]

A lot of aboriginal people had diets high in protein - just think of the Inuit. Their diets were also high in fat, of course.

But I really don't think they were afflicted with kidney problems.