A streamlined stack of supplements designed to meet your most critical needs - Adapt Naturals is now live. Learn more

Do High-Protein Diets Cause Kidney Disease and Cancer?

by

Last updated on

protein and kidneys
Do protein sources like this increase the risk for kidney disease? iStock.com/Smitt

It seems like every other week there is a media uproar about the dangers of any number of foods. Lately, the target has been meat – specifically high-protein diets – and its supposed connection to a range of chronic diseases and early death.

I’ve discussed high-protein diets a on my podcast here, but with the recent press surrounding a new study on high-protein diets and cancer risk, there’s been yet another upsurge in concern over their safety.

In this article, we’ll take a look at the research behind three of the most common concerns about high-protein diets: kidney health, cancer, and longevity. By the end of this article, you’ll know what the real danger underlying high meat consumption may be, and how you can easily avoid it by eating a Paleo diet.

Will a high protein diet give you kidney disease and cancer? Find out here!

High-Protein Diets Don’t Cause Kidney Disease in Healthy People

Before getting into this, I want to make something clear.

Research does show that high-protein diets can be harmful for people who already have chronic kidney disease, and low-to-moderate protein diets are generally advisable for these patients.

However, just because a low-protein diet can be therapeutic for those with kidney disease, doesn’t mean a high-protein diet causes kidney disease in the first place. (This is the same distinction I made when critiquing Dr. Perlmutter’s broad recommendation for a low-carb diet to prevent neurological disorders.) What I’m addressing here is the notion that high-protein diets cause kidney disease in healthy people—which is not, as you’ll find out, supported by research.

Since one of the main biological roles of the kidney is to metabolize and excrete nitrogen byproducts from protein digestion, many people believe that eating more protein will ‘strain’ the kidneys. This is similar to the argument made against acid-forming diets. There is an upper limit to the body’s ability to metabolize protein (studies suggest that this limit is around 35 percent of total calories), but the brain has specific mechanisms that regulate desire for protein, and these mechanisms are difficult to override through willpower alone. (1)

It’s clear from controlled trials that high-protein diets do induce measurable changes in kidney function. (2, 3, 4) These changes include increases in glomerular filtration rate (GFR) (often referred to as “hyperfiltration”), and an increase in the size and volume of glomeruli, which are the functional filtration units of the kidney. (5) The sticking point seems to be in how these changes are interpreted, because while some researchers view hyperfiltration as a sign of kidney stress and even damage, others view it as the kidneys simply getting better at doing their job.

The best paper I’ve found to explain this issue shows that hyperfiltration is a normal adaptive response to additional protein in the diet, as opposed to a pathological condition that will eventually lead to kidney disease. (6) Pregnancy is discussed as one case where GFR increases significantly, but does not increase the risk for kidney disease.

A more compelling example is that of someone who has donated one of their kidneys, because in these cases, GFR in the remaining kidney increases as an adaptive response and remains elevated. One would expect that if hyperfiltration leads to or indicates kidney disease, increased kidney disease would be found in these patients down the road. However, studies have not found a higher risk for kidney disease in patients with one kidney, even 20 years after donation.

After reviewing all of the published research on high-protein diets and kidney disease, the authors of this paper concluded that while high-protein diets can be harmful for those with kidney disease, they do not harm the kidneys in healthy individuals. Since that paper was published, new studies have tested the effects of high-protein diets on renal function in healthy individuals, and generally, their conclusions are the same. (7, 8, 9)

The Newest “Meat Will Give You Cancer” Study

Now to the primary motivation for this article: the study behind headlines such as “Diets high in meat, eggs and dairy could be as harmful to health as smoking”. In this study, researchers reported a positive association between high protein intake and cancer incidence based on observational evidence from people between the ages of 50 and 65. (10)

However, they found that high-protein diets were actually associated with lower mortality from cancer in people over 65. (In this study, “high protein” was defined as at least 20% of calories from protein.) Importantly, this relationship only existed for animal protein; researchers found no relationship between a high consumption of plant protein and cancer or mortality.

For a thorough critique of this study, I recommend reading Denise Minger’s analysis. As she points out, the oft cited “healthy user bias” is less relevant to this study because protein hasn’t been demonized such that people who eat more protein would be expected to have unhealthy lifestyle habits. In fact, the high-protein participants in the study actually had slightly lower rates of smoking.

The major downside of most observational studies is that they don’t shed light on the mechanisms behind the associations they uncover. On this point, this study is designed better than most. Researchers hypothesized that increased IGF-1 activity due to high protein consumption may lead to a higher instance of cancer and an earlier death, so after observing a positive relationship between these variables, they designed a mouse study to test the mechanism of their hypothesis.

They found that mice eating a higher protein diet (18% of calories) grew larger tumors at a higher rate than mice on a low protein diet (4-7% of calories), and that the high-protein mice had higher levels of circulating IGF-1. (IGF-1 is a hormone that prompts cell growth in almost every tissue of the body.)

This is unsurprising, as earlier animal studies have shown that increasing protein intake (especially from isolated casein, which tends to promote cancer growth more than other sources of protein anyways) increases IGF-1 levels, and it’s well-known that IGF-1 encourages the growth of cancer cells as well as healthy cells. However, as Denise brings up in her analysis, total protein restriction is only one way that researchers have been able to decrease circulating levels of IGF-1 in rodent studies.

Like what you’re reading? Get my free newsletter, recipes, eBooks, product recommendations, and more!

Is Protein to Blame—or Is Methionine?

This is also where the issue of longevity comes into play, because increased levels of IGF-1 are thought to contribute to accelerated aging and shorter lifespans. Many early studies found that calorie restriction reduced IGF-1 and increased lifespan in many animal models, in addition to protecting against cancer. (11) Researchers then discovered that restricting total protein—but not total calories—accomplished the same goal, often more effectively than calorie restriction. (12, 13)

Recently, the amino acid methionine was targeted as the primary operator in the protein/IGF relationship, and new animal studies demonstrated that methionine restriction alone was able to reduce IGF levels and extend lifespan. (14, 15, 16) Methionine is an amino acid found primarily in muscle meats and eggs, and I frequently emphasize the importance of maintaining a healthy methionine-to-glycine ratio by consuming glycine-containing foods like bone broth and gelatin.

This evolution of research from calorie restriction to methionine restriction is already fascinating, but here’s the kicker —a study done in 2011 found that supplementing with glycine had the same life-extending, IGF-reducing, health-promoting effects as restricting methionine intake (and restricting protein intake or overall calories)! (17)

Eat the “Odd Bits”!

Granted, this is one study, and it was done in mice. But from an evolutionary perspective, this connection makes perfect sense! Until recently, humans were not getting a majority of their protein from high-methionine foods such as muscle meat and eggs. We just didn’t have the luxury of heading to the nearest grocery store and picking out steak, chicken breasts, and pork tenderloin.

It can be easy to forget when these cuts are all packaged up nicely in the store, but those “prime cuts” used to be attached to bones, cartilage, skin, organs, and all the other odd bits that now usually end up in pet food (so at least Fido is getting his glycine!).

These odd bits (especially liver) also have other nutrients, in addition to glycine, that help the body metabolize methionine, including vitamins B6, B12, folate, betaine, and choline. As is often the case, traditional foods have a range of nutrients that work together synergistically, and whole foods tend to be much healthier when they’re left whole.

So, will a high-protein diet give you kidney disease and cancer? As far as kidney disease goes, the research suggests that the answer is no. But when it comes to cancer and longevity, it depends on the overall context of your diet.

If you’re getting a high percentage of calories from protein, and you eat muscle meats and eggs without glycine-rich foods and organ meats, there is reason to believe you may be at higher risk for cancer. Fortunately, if you’re following the advice I outlined in Your Personal Paleo Code (published as The Paleo Cure in paperback in December 2014) and “eating nose-to-tail”, you need not be concerned about eating a high-protein diet.

ADAPT Naturals logo

Better supplementation. Fewer supplements.

Close the nutrient gap to feel and perform your best. 

A daily stack of supplements designed to meet your most critical needs.

Chris Kresser in kitchen
Affiliate Disclosure
This website contains affiliate links, which means Chris may receive a percentage of any product or service you purchase using the links in the articles or advertisements. You will pay the same price for all products and services, and your purchase helps support Chris‘s ongoing research and work. Thanks for your support!

81 Comments

Join the conversation

  1. It seems common to use a form of dairy dried in high temperatures to serve as the protein source in studies, and I haven’t read yet that this could in fact be the problem. My understanding is that when dairy/casein is dried and heated, it changes from a food to a dangerous substance. In reading abstracts by labs that create this important scientific product, it appears they work to find ways to create a more efficiently hazardous protein so related studies can progress as desired. What human would eat 12% or their daily protein in the form of highly processed casein? If they added rat poison to the casein, would they still claim it’s the protein doing the harm? I agree that comparing naturally raised meats to CAFOs should also be a standard by which these studies are evaluated. First, commit to giving rats real food protein (unless you are comparing cake mixes), and then categorize the protein by whether it’s raised naturally or in a CAFO.

  2. Why are dietary intake trials always expressed in terms of the food being studied as a percentage of calories consumed?

    Surely it would be the amount in grams per day (or meal) of meat the Kidney has to deal with, or the amount per minute the kidney has to deal with that is the relevant factor?

  3. The science is definitive: The Hepatitis B vaccine is not only associated with liver disease, it causes it. The specific harm done is known, clearly documented. Low doses of the hepatitis B vaccine with aluminum adjuvant results in loss of mitochondrial integrity, cell death, and apoptosis, particularly in liver cells.
    ———————————————

    http://www.greenmedinfo.com/blog/hepb-vaccine-causes-liver-disease-science-shows-how

    The government has a large scale depopulation program ongoing in the US and globally. It will keep getting worse as they expose people to new toxins. The toll will just keep mounting as people ignore it. Ignorance is bliss attitude won’t make the problem go away.

  4. I too have been wondering about eating eggs every day without glycine.
    Is it better to follow the eggs with a Greatlakes gelatin chaser?
    That seems to me to be the easiest thing to do. HELP

  5. This is day 30 on my reset and I feel terrific. Have shed a lot of fat, look way better, have more energy with no stiffness.
    Still bothered by something and I’m going to eliminate coffee next week to see and stay on the 30 day reset plan for a few more weeks to lose more fat.

    • Blue mussels, Mytilus edulis seem to be a good source of glycine
      “High concentrations of glycine, also a constituent of mussels’ adhesive proteins, were also found in all fractions with the highest observation in the 50 kDa fraction with 5.0% of glycine.
      Glycine, taurine and alanine are the most representative amino acids in volume regulation of Marine . Drugs 2013, 11 981”
      Would canned smoked mussels lose it’s glycine due to prorcessing?

  6. I seem to be getting urinary infections – or what feels like them – since I upped my meat and protein intake to about 12 ounces per day. Most of that is fish, but about 4 – 5 ounces is often red meat. I’m wondering now if that increase IS “straining my kidneys.” Symptoms are odor and a feeling of “soreness.” I seem to need TONS of water anyway. Maybe I do need to cut back on the meat.

    • Hi Debbie,

      I’m not sure if this will help, but in terms of needing a lot of water, I used to be constantly thirsty (literally 24 hours a day, 7 days a week, for 15 years). I found that when I went to a low-carb diet, my constant thirst went away. And I find that when I occasionally have a high-carb meal, the thirst comes back (it takes 1-2 full days for my body to get back into ketosis so the thirst goes away again).

      In terms of the amount of protein, I’m 180 lbs. and I eat an average of about 6 ounces of protein a day. Usually red meat or chicken, fish rarely. My digestive function and urinary function have been more comfortable and reliable since I changed to a low-carb diet than they were for the previous 15 years.

      Finally, as some other comments have stated, eating grass-fed meats may be more important than the type of meat (red meat, fish, etc.). I have a friend that’s had allergic reactions to milk for over 5 years, but recently discovered she can eat milk products from grass-fed cows without problems. So if you’re not already, I suggest trying to eat meat, eggs and dairy only from pasture-fed animals for 3-4 weeks and see if it helps. (And keep in mind that it may take this long for you to notice a difference, since some of the chemicals given to CAFO animals can stay in your system for weeks).

      Hope it helps!

  7. Hi Chris,
    This article is SO timely for me! My doctor is currently running some tests on me, one of which are blood tests which came back showing out of range #’s for my kidney function. I never thought the paleo diet I began 3 years ago, after being vegetarian for 12 yrs., would be the cause. But, I did donate a kidney 4 yrs ago and was wondering if that had anything to do with the #’s. I just purchased your book and can’t wait to read it! Thank you, thank you, thank you for your invaluable help in my continued quest to get and stay healthy.

    • I am curious about this as well.
      Is it dietary or endogenously produced glysine that is causing the problem? Or could it be an effect after the cancer cells have begun to grow?
      Might this be similar to recommendations for lower protein intake for people with already established kidney disease?
      In other words, glycine can or should be part of a nutrient dense diet in people currently free of certain cancers.
      This is all hypothetical. I just wanted to put my thoughts out here.
      Thanks Chris, great article.

    • Just thought I’d chime in to say that these are only cell studies! They didn’t look at glycine consumption in the human population and see whether it’s associated with cancer, they just found that glycine is important in cancer cell metabolism. This tells us nothing about what we should eat, because that’s not what the study was trying to do. I think you should consider that some of the healthiest groups of people in the world, ala WAP, routinely ate lots of glycine.

  8. This definitely makes me rethink my diet. I was diagnosed with Breast cancer in August 2013 after about 2 years of a paleo based high protien diet. I’m 34. At the time of diagnosis I felt better than I ever had in my whole entire life. It would be nice to know the WHY, but who knows if that will come in my lifetime. Now I wonder, even though I felt great and thought I had tweaked my diet pretty well, was the high protien intake a contributing factor? My risk factor was less than 5% to begin with. My chance of reoccurance is less than 5%. It would be nice to find a diet that would help ensure I don’t have go through cancer treatment again.

    • Hi Jennifer, I have been eating paleo for a few years, before that I ate higher protein and carb reduced diet. I too was diagnosed with BC in 2010 at age 40. From what I understand cancer takes many years, if not decades to develop into a tumour. I don’t link my high protein diet as a direct cause of cancer, for me, I look at early childhood issues such as growing up in a mill town, being exposed to second hand smoke as a developing adolescent, dairy consumption, a tendency toward low thyroid/estrogen dominance during my 30s, and not having children among the few risk factors I had. I do however have high levels of IGF-1 which I am seeing some improvement through a strict dairy free diet. Don’t throw out the paleo diet just yet, perhaps you can talk to a doctor who specializes in complementary medicine to get a second opinion. Best wishes to you!

  9. I read in a Broda Barnes book that high protein diets (without enough fat) can utilize available thyroid hormone. In essence, reducing metabolism. He mentions two research studies that found high protein diets lowered basal metabolism. That was long ago. I’d like to see Chris check out any recent research on high protein and thyroid.

    And as Wenchypoo made clear — the raw form is another story. i know most people are eating cooked meat, but some raw meat is a good thing! A video: http://youtu.be/Z9g_EGbnfxo

  10. I do not have kidney disease, but I was born with only one functioning kidney. That one kidney functions fine, but I have been trying to determine if that still puts me in the caution category. I have read when you only have one kidney, the other will grow larger and compensate for that, but it still seems like i would have less kidney function that a person with two healthy kidneys. I do have a detox/methylation/histamine problem and therefore cannot eat bone broths. I do eat organ meats though. Perhaps I should eat lots of organ meats and minimal muscle meat?

  11. I have advanced kidney disease (pre-dialysis) so I have to be careful about my protein intake and have serious questions about going ketogenic what with acidosis being a real threat to me.

    My point is, that kidney disease is a silent killer. Unless you are routinely tested–and most people aren’t– you have no idea whether your kidneys are healthy or not. I am still relatively asymptomatic, even in my advanced state of decrepitude. So it is very easy to go along thinking you have nothing wrong with your kidneys when in fact trouble may be brewing.

    On the glycine front, I have started taking a daily pure glycine supplement. I take it as a sleep aid, but it’s nice to know it’s helping in more ways than one.

    • I absolutely agree with you!

      Who knows if he/she has “healhy” kidneys? There are “subclinical” conditions that register stil as “low normal” on the testing scale!
      I know that “something” is not quite right with my kidneys, even though my MD keeps telling me I’m ok. I do best when I eat moderate amounts of protein!
      i was horrified when I read in Chris’ new book how much protein he suggests! This can not be right for everyone! And I do not believe that we “instinctively” know HOW MUCH protein we should eat!
      I am European, and am horrified by the huge portion of protein served in the USA…steaks that could feed a family of five! Is it the INSTINCT of these Americans telling them to eat this much protein? I don’t think so. Its probably just HABIT and availability!
      My “kidney condition” could, perhaps, be congenital since my father had the same thing. Or. “maybe” I simply DON”T need that much protein.
      I have learned -via trial and error – that I do best on ca. 40- 50g a day!. Eating as much portein as Chris suggests in his book would make me physically unfuctionable!

  12. Chris,

    Thank you for another excellent article. Do you have any info about how much glycine is ideal? We eat lots of high quality meats and eggs. We do make bone broth and eat the “more intersting” parts of animals occasionally but we also add 1-2 TBSP of high quality gelatin everyday. Are we in the ballpark of keeping glycine high enough?

  13. Hi kris, i have protein virtually 6 nights a week, would that be hareful, for me, only i always thought protein was extremly good for you, it was good for your hair, skin, nails etc….if you think iam eating far to much protein in my diet, could you please just let me know, thanks kris, @ hey your emeep me going, they are absolutely fanbtastic, …… byeeee x

    • There are some essential foods we must eat because our body’s cannot synthesize them. Vitamins are classified as such, so are certain fatty acids (omega 6 and 3 for example) as are about twenty amino acids (lysine included). There are no “essential” carbohydrates, but plants do provide other essential nutrients like vitamins.

      The native Greenland diet is nearly solely meat and fat based, and due to the low temperatures they eat a lot of calories. They seem to do pretty well on this diet.

  14. Also remember everyone, for good health try to cook your meat at low temperatures, as Stephan Guyenet and Denise Minger have previously told us.

  15. I eat eggs and meat all the time, but hate liver. What other options are there for us to get our glycine. Is one soap bone broth enough to offset eating eggs and meat? Really need to provide more information.

    • Hi, I hate liver too; but I love home made chicken liver pate. I also buy a good brand duck liver pate. Hope this helps x

    • Glycine isn’t really found in very high levels in liver, either. It’s found in the collageny bits. If you make a bone broth and let it cool, it should gelatinize. That’s how you know you actually extracted the glycine. The best thing for this is apparently chicken feet, but it can be done with shanks and other bits too. Also, glycine is found in the skin of animals, so if you can get low-omega-6 chicken or pork skins, that would work. If you make one pot of bone broth (that actually gelatinizes) every week, that should be great. Even every 2 weeks should be fine. If you skip liver, just make sure you have other sources of B12, folate, Vitamin A, etc. Liver is just an easy concentrated source for these nutrients, some of which are important in the methylation cycle Chris was discussing. Certain greens, oysters, kidneys, etc, are possible sources.

  16. OK. So is it possible to get adequate Lysine without eating organs from animals? If so, how?
    ~~~

    • Hi Jake,

      You asked: “Is it possible to get adequate Lysine without eating organs from animals? If so, how?”

      I believe you meant to ask if it were possible to get Glycine without eating the organ meats, and indeed it is: you can eat gelatin. If you like Jello, you can make it weekly, and eat a little bit at a time. Many people claim that it improves their sleep, so you may want to eat it at night.

      But make sure that you get the vast array of micronutrients that you would otherwise be getting from things like liver elsewhere. It’s interesting to see how nutrient-sparse muscle meats are when they’re compared to organ meats. I think it’s notable that the French, who are the longest lived people in Europe, consume lots of these organ meats and gelatinous foods.

      • Thanks Birgit, Glenn, & Karin.

        I guess it’s easy enough to supplement with L-Lysine, a 1/2 tsp. added to my morning “cocktail” would supply 2g. Question is, how much is too much? Too much Lysine can cause gallbladder and kidney stones .. no thanks.

        But I’d much rather eat foods. I can handle liver & onions, but I can’t make myself eat liver from a CAFO cow. I need to know the cow is/was healthy.

        Certainly broth is in, and the resulting soups, and gelatin is fine, though I won’t eat jello with sugars of any kind, unless it’s Xylitol or Stevia.

        Not sure how you measure 1 oz. of “egg, white, dried”, but if there’s 5g of Lysine in that, seems those who eat a lot of eggs would be getting plenty. But then a “cup” of “egg, yolk, dried” only yields 2.7g. And you know cage-free, free-range, organic eggs are gonna be different in some kinda good way. Go figure.

        But thanks again, everybody.
        ~~~

        • Hi Jake,

          It’s definitely GLYCINE that you want, not lysine, which is another amino acid.

          I absolutely agree with you about CAFO meat. I know that you can’t find non-CAFO meat at most supermarkets, but I give my children liver that I buy at the farmer’s market. May I ask where you are? I’m sure that somebody on this thread can help you find a healthy and more humane source.

          I make them gelatin with fresh squeezed orange juice and a little erythritol/stevia. They love it. 🙂

          • LOL. Yes, GLYSINE is what I meant, of course. And like lysine, it’s easy to supplement.

            I live about an hour north of Atlanta. Your jello sounds good, and that would be healthy enough for me, on occasion.

            Thanks Karin.
            ~~~

  17. I’m not a fan of eating organs and cartilage (thinking brisket or rib meat), but I make bone-cartilage broth and have it regularly. I hope that’s enough to balance my lean meat intake with glycine and the other nutrients.

  18. I have to wonder if the kidney studies were at all broken down by sex, because after looking at CMPs since we started eating Paleo, then keto, it seems (according to kidney values) my husband better tolerates higher protein than I do.

    I also have to wonder if all these high-protein studies were at all based on the kind of meat we eat: grass-fed and/or pastured. I bet not, as studies usually aren’t.

    Since our kind of meat animals eat grass, I also have to wonder (again–me with the wondering, right?) about the study results if the patients were fed grass-fed meats and plant-eating fish–where the animals have already consumed our carbs FOR us. I believe they purposely avoid testing with this kind of meat because:

    1. CAFO meat is cheaper and easier to get, and
    2. they are afraid of the results.

    If we started testing using grass-fed, pastured meats, with the nutrient content different from the start, I’m sure we could easily upend the last 80 years’ worth of research, and it will show a hell of a lot of people died for nothing…just as people continue to die for nothing but the sake of profit–both monetary and political.

    • Re: kidneys again–from a cat perspective this time. I own a cat with CKD (now called CRF), but it means the same thing–kidneys headed south due to age. I was told the same old song about how protein avoidance was paramount, because protein levels of meats were just too high for him to handle any more.

      After some serious combing through the NBD to find out which meat shad the lowest levels of protein, I made a discovery: cooked meat was 3X higher than RAW meat! Since we eat grass-fed, pastured meat around here, I looked up raw versions of what we already have on hand. Turns out the wilder, the better, because the meat is already less acidic from the grass and lack of grains.

      Since I was never given an upper limit for protein, I now make my own food out of offal from the wildest animals I can get, add copious quantities of fat, and serve twice daily. Basically, my cat’s also eating keto.

      Now he has no iron problems, no reflux problems, and his kidney values have held at Stage 1 for about 3 years. I include dandelion, nettle, and cranberry tinctures to keep the urine flowing, because that’s how the toxins keep from building up. I also dilute his food with lots of water, since he no longer gets the urge to drink much.

      If I can halt a cat’s progress using the one food they say he CAN’T have–meat–why can’t doctors do this for humans? It’s not hard…well, the hardest part is catching the disease early, and this is where CMP testing comes in.

      He’s a cat, for crying out loud–do they REALLY expect him to live on by-products, soy, and multitudes of drugs?

      • Hi.

        I love your reasoning and please avail yourself to the web address I have posted above.

      • I love your comments. I would ALSO like to see studies where the source of the meat is CLEARLY described so we can hold up a study done on CAFO meat that (probably) increases risk of cancer against a study done on pastured meat that (probably) decreases risk, and point at them enthusiastically. Isn’t this the missing piece? SO MANY PEOPLE think meat = cancer, and I just don’t buy it.

        I also have two cats, and the 6 year old male had lots of urinary issues, to the point where I was fooled into thinking he had a behavioral problem and was peeing on the floor out of some kind of social discomfort….nope, it was bladder pain. I feel eternally horrible for not realizing it sooner, but I had him on the Hill’s Science Diet crap food because it’s what every vet prescribes when 80% of male neutered cats have this problem. Finally I did some digging and figured out that, oh hey, duh, cats should NOT BE EATING RICE AND CORN. I switched him to all grain-free wet food and his problems disappeared within a week. I still feel so bad for putting him through that for a couple years, but now I do my best by all cats to strongly suggest their owners follow suit. I’d love to move to a raw/wild diet for them but it’s not quite feasible for me yet.

        Take home message: eat what you’re designed to eat. Humans are omnivores, cats and dogs are carnivores. Rocket science, right?

        • Could you tell me which wet food your using? My cat also is having urinary issues and was recommended Friskies crappy wet food for urinary issues.

  19. Does it mean that eating eggs without eating glycine-rich foods may be harmful? Interesting and a little unnerving.

    • Well, egg yolks contain folate and are one of the best available sources of choline, and as Chris said, both of those nutrients help metabolize methionine. So it definitely seems like eating the whites without the yolks could be harmful, but since eggs are definitely a whole food, I wonder if those nutrients are enough to ‘balance out’ the methionine content.

    • Thank you Chris, for this article, which is bang on!

      However, when it comes to cancer, a very important distinction is the following:

      Cancer is a Significant Biological SPECIAL program of Nature.

      http://learninggnm.com/documents/testimonials.html .

      Dr. med. Mag. theol. Ryke Geerd Hamer has discovered 5 Biological Laws of Nature, which have elevated medical science to a true science, which is 100% predictable, explains the causes and the cures of all diseases including all so called cancers, in 1981.

      Cancer is NOT a condition to be fought, but rather it is to be understood.

      It seems, that this SPECIAL program is initiated by the psyche through the brain to the body (all of which is synchronous) particularly when the body does not have adequate resources to cope with “life situations”.

      That is why your article, Chris, is bang on, because it is very important to have balanced nutrition at all times in order for the body to have all the resources it needs.

    • Probably not because eggs actually contain more glycine than methionine! The glycine is concentrated in the yolk, while most of the methionine is in the white.

    • The best-tasting, easiest and least expensive source of glycine has to be home-made chicken soup because you use the skin, giblets and bones (including the cartilage-rich joints) to make it. After only 2 hours of simmering, it will have enough glycine to gel easily when refrigerated. Other bone broths take much longer.

      My favorite high-glycine snack is pork rinds.