92 Responses to “Animal protein as bad as smoking?!”

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  1. avatar Hellooutthere says:

    “2) Relative risk is a poor measure when absolute risk can be reported instead. (You can double your chance of winning the lottery by buying 2 tickets. Your relative chance is twice as high as it was before. Your absolute chance was 1 in 14 million and is now 1 in 7 million. You’re still not going to win the lottery!)”

    Actually, if you buy 1 ticket you have a 1/14m chance of winning the lottery.
    If you buy 2 tickets you have 2, 1/14m chances of winning the lottery.

  2. avatar Lisa Chase says:

    Dang, my link didn’t work…I was afraid of that. I guess I don’t know how to post a link onto a comment section of a website, never tried to do it before…..

  3. avatar Lisa Chase says:


    Well, it was not really *my* point about carbohydrate and cancer; I was only quoting what many cancer researchers are now saying. And I feel I must clarify something: I (and they) are not making the claim that carbohydrate *causes* cancer, only that carbohydrate and sugar promote tumor growth in the case of already existing cancer. (To be fair, I may not have made this clear enough in my comment). Any researcher worth his or her salt would not make a bold claim without a heck of a lot of research to back it up, so most cancer researchers admit that we still do not know exactly what *causes* cancer- though many theories abound, and risk factors have been established for certain cancers. (This is partly why I am irritated by the above “20 Cigarettes a Day” article; I find this sensationalist headline misleading and irresponsible). Unfortunately, I erased the link to the lecture I was quoting from, and can’t find it again (and I’ve forgotten what it was called). But if I find it, I’ll be sure to post it.
    But if you want to learn about the cancer/sugar connection, look up the work of Dr. D’Agostino. You can also look up Dr. Thomas Seyfried, who uses a low-carb ketogenic diet to treat cancer- (granted, it’s also protein restricted, as he tries to get blood glucose to a very low level. But it’s even more carbohydrate restricted, due to carbohydrate’s larger effect on blood glucose). If you google high protein/low carbohydrate diet + cancer, you’ll see there were mouse studies done with mice with breast cancer, and those on a low carb/high protein diet had slower tumor growth and lived longer than the mice on a high carb/lower protein diet. I tend to be a bit skeptical about animal studies, but there also seems to be a link in humans between breast, ovarian, and other hormonal cancers and high carbohydrate diets (I’ll find the links if you want). In any case, here’s a link to an article about another researcher I found out about today:

    Jane Macdougall: What does cancer eat? Sugar, mostly, …

    On anther note, I read your comment about protein and people over age 65, but there’s still one thing that’s not clear to me. Basically, you explained that people over 65 need more protein- okay, that’s fine- but that still doesn’t explain specifically why animal protein is suddenly “positive” and no longer “negative”. (As you may recall, the article differentiated between animal and plant protein). My question remains: why would one type of protein be bad at a certain age, but good at another age? I would also like to bring up the point that some plant proteins are hardly benign! Gluten, for instance, is for many people a very toxic substance, and some people also have certain issues with soy and other legumes. I think it’s wrong to make a blanket statement about what kind of protein we all *should* be eating.

    I guess what you said about Weston Price, I could also say about this study, ha ha……

  4. avatar Brian G says:

    Thanks very much for this Zoe … the public at large hasn’t a chance of making good nutritional choices with ‘Protein bad as smoking’ type headlines like this. Sad to say, sensational headlines sell.

    Dr Jason Cholewa is as impresed as you are with the study http://jasoncholewa.com/2014/03/05/high-protein-diets-cause-cancer-study-says

    In related vein, Prof Colin Campbell’s The China Study has strongly influenced the thinking of many and as The Power of Placebo (recent BBC Horizon topic) seems to be accepted by med orthodoxy, it may have been helpful … or not.

    In dealing with a prostate health issue (high PSA score) I have tackled it using diet. Twice, over the last six years, I have reduced the PSA level significantly and quickly by eliminating dairy – I am a dairy-loving lacto vegetarian by choice. Even eating recommended A2 raw dairy and avoiding A1 didn’t stop exceeding 11.17 ng/mL. See http://thebovine.wordpress.com/2009/03/20/the-devil-in-the-milk-dr-thomas-cowan-on-how-a2-milk-is-the-answer-to-the-mystery-of-why-even-raw-milk-sometimes-does-not-seem-to-be-enough-of-an-improvement-over-store-bought

    I wish the placebo effect had worked for me! There are so many factors that can influence blood tests, but I am reluctantly avoiding the Waitrose raw French cheese display.

  5. avatar Mie says:


    “I read a lot about cancer, due to personal interest, and the latest research by cancer experts pinpoints sugar and carbohydrates as being the biggest drivers of cancer growth; protein has only a moderate effect, and fat has essentially no effect (so much for the myth that animal fat causes cancer).”

    Feel free to mention a least a couple of studies indicating that carbs per se have major carcinogenic potential. Or define “the biggest drivers”. On parallel with e.g. tobacco?

    “As for Weston Price: I, personally, hold his research in high regard.”

    Feel free to do so. Doesn’t change anything.

    “One can choose what one wants to believe, but I personally find many so-called “scientific” studies of today too limited and reductionist in approach; at least, too reductionist to make any valid conclusions about. There is a synergy in foods and their nutrients which we haven’t even begun to understand, and isolating only one element is bound to be misleading. This is why I have a lot of trouble with many studies, like this one.”

    You’re not barking up the wrong tree there. However, the current opinion in e.g. nutrition has shifted/is shifting towards entire diets instead of isolated elements.

    But but … Isn’t your point about carbs & cancer precisely reductionism? :-)

  6. avatar Robin Willcourt says:


    More absolute rubbish, coming out of Australia this time- no surprise! We can NEVER seem to get anyhting right!

  7. avatar ivor cummins says:

    The authors of the report failed to include their supplemental data, but I did find it and carried out a brief analysis; unless I’m missing something, this Study is far worse than the average epidemiological one. That is because it seems that it’s not just poor in the claims made without proper causation being proved – in fact they should have known from the data that their conclusions were effectively impossible to claim. See my brief analysis below, and if you have a basic scientific, engineering or statistical background, you can decide for yourself:


    • avatar Zoë says:

      Hey Ivor – I love it! Just tweeted it. Don’t suppose you’ve had any luck getting numbers out of the ‘researchers’? I’m after deaths for the 50-65 year olds and over 65s by protein group (low, moderate, high).
      Bye for now – Zoe

  8. avatar Rod says:

    If the 65+ group is not having the most deaths, we need to know what mine the data came from.

  9. avatar Lisa Chase says:


    I read a lot about cancer, due to personal interest, and the latest research by cancer experts pinpoints sugar and carbohydrates as being the biggest drivers of cancer growth; protein has only a moderate effect, and fat has essentially no effect (so much for the myth that animal fat causes cancer). My guess is it’s probably insulin related, as both carbohydrate and protein can cause insulin spikes, but protein to a lesser extent. I saw a lecture where a cancer specialist recommended that people who are prone to cancer eat a low carbohydrate, high fat diet. He was less concerned about protein, though obviously you don’t want to go crazy with it. I just read the Jaminet article that W linked to, and what they say about protein and cancer growth makes sense to me, based on other things I’ve read and heard.
    As for Weston Price: I, personally, hold his research in high regard. He had the rare opportunity to observe people who were all eating the same native diet, so it was much easier to make comparisons about these various diets without confounding factors. Nowadays, we eat very different diets and have more different lifestyles, so how can you even pinpoint *what* factor is causing which result? Not to mention the fact that he was also often able to compare these people to others of the same group who had switched to a modern diet. In addition to that, he took samples of many of the foods he came in contact with and meticulously tested them for vitamin and nutrient value. One can choose what one wants to believe, but I personally find many so-called “scientific” studies of today too limited and reductionist in approach; at least, too reductionist to make any valid conclusions about. There is a synergy in foods and their nutrients which we haven’t even begun to understand, and isolating only one element is bound to be misleading. This is why I have a lot of trouble with many studies, like this one.

  10. avatar David Ramsey says:

    *if we need them

  11. avatar David Ramsey says:

    Ray peat has written many articles about the misnomer of “essential fats” simply concluding that it is absolutely not essential. Chris masterjohn wrote a special report on the pufa which concluded that humans need less than half of one gram of pufas per day. William e m lands the expert on so called essential fats has demonstrated that above the level of 1% consumption of pufas as calories is where disease rates begin to dramatically escalate. The point is that of we need them we need them in incredibly minute quantities. The unstable nature of them leads to the vulnerability to oxidation and molecular defeneration when in a human body. Also if they were so essential to our survival why would the human soecies not have adapted to make them? Ray peat explains about the damage they do to thyroid hormone and that they are essential only in the development of cancer and heart disease. I was curious why you think humans don’t make them? Also why would ruminants have evolved the digestive system which detoxifies pufa if it were essential??

    • avatar yeah says:

      you should avoid all PUFAs as they are unhealthy (seed oils, etc). I’m pretty sure saturated fats (mainly from animals) are the fats Zoe is referring to as being healthy.

  12. avatar Sab says:

    These types of studies on food annoy me. There are way to many variables to ever fully say protein amounts could be the cause of anything. Unless you ran a study which divided people into multiple groups all of which were eating the exact same foods just in different proportions then you can’t rely on most of these types of studies. To get a more accurate account you would have to have groups that are high protein and low but you would also need to show if these results are affected by either a high carb or high fat diet as well as a high fat and low fat diet. How do we know these people weren’t also eating chemical madden garbage along with the higher protein etc….

  13. avatar pete schubel says:

    I find the claims on proteins effect on cancer the most troubling. If you look at the data supplied in Table S1, it gives the participants history of cancer prior to the study. 11.7% of the folks in the low protein diet had a history of cancer while 7.5% in the moderate protein group and 5.0% in the high protein group. Understanding there are a ton of variables not accounted for, it would appear that high protein diet offered a protective effect against cancer for the years leading up to the study. For the actual study period, the cancer rates between the three groups were essentially the same. The only way they could claim a significant difference is if they broke down cancer deaths from 50-65 and over 65, the theory being that a low protein diet protects against cancer from 50-65 and than promotes it after the age of 65. So in summary, low protein diet appear to cause cancer until age 50, protect from 50-65, and than promotes it again after age 65. Doesn’t seem to pass the sniff test.

    • avatar Zoë says:

      Good spot Pete! Also in S1 total mortality is 40.4% – 39.6% in the large moderate protein intake group (75% of participants) and 42.9% in both the tiny (6-7% participants) low protein intake group and in the still small (18% of participants) high protein intake group. Surely the headline is moderate protein intake is best for overall death rate?
      Still not got the raw data – the deaths in 50-65 and 65+ will be the most interesting
      Best wishes – Zoe

  14. avatar W says:

    Paul Jaminet, co-author of “The Perfect Health Diet,” has posted his analysis of the study; he too finds it lacking in credibility; part of his analysis:

    “If they wanted us to understand whether their results are trustworthy, authors would present raw data, and then a sensitivity analysis that shows how introducing each covariate individually affects the results, then showing how including combinations of two covariates affects the results, and so forth. This would help us judge how robust the results are to alternative methods of analysis.

    “Of course, authors do not do this. Instead, they ask us to trust the analysis they have chosen to present – which is only one of billions they could have done. (This study adjusted for 13 covariates. The NHANES survey may have gathered data on, say, 40 variables. There are 40 choose 13, or 12 billion, possible multivariate regression analyses that could be performed using 13 covariates on this data set. Each of the 12 billion analyses would generate different outcomes.)”

    More here:

  15. avatar Mie says:


    what Weston Price (with or without the foundation) has to offer to us is that limited observations lead to ecological fallacies which leads to pseudoscience (the same applies for vegan nonsense, e.g. “The China Study”).

    And about “logic” part: read the study, please. Or my comment above.

  16. avatar david ramsey says:

    Hi, thanks for the post. I’d like to know what you mean when you say this…”Not unless you want to deprive yourself of essential fats,…” What is your stance on essential fats?

    Thanks again.

    • avatar Zoë says:

      Hi David – I’m not sure what you mean. There is no stance to be had on “essential fats” – just facts. Essential in nutrition means it’s essential that we consume the substance – the body can’t make it. Without essential fats (omega-3 and omega-6) we die, so we need to consume them. Fortunately nature puts them in most foods – all animal foods (meat, fish, eggs, dairy) and some plant foods – the ones that contain fat (avocados, olives, coconuts, nuts, seeds etc).
      Best wishes – Zoe

  17. avatar Park says:

    Another great analysis! I found another on examine.com, but I like Zoe’s better. I’ve read a lot of studies over the last few years and have tried to hone my bullshit detector, but I can never ferret out the salient details like Zoe.

  18. avatar Lisa Chase says:

    Well, excellent article and so many good comments that there isn’t much I can add to the discussion. Except that Weston Price noticed that the healthiest groups of people he encountered ate more animal protein (and quite a bit more animal fat!) than the average Westerner. It’s interesting to note that the theory of many explorers at that time was that hunter gatherers and other traditional groups didn’t get cancer precisely *because* they ate meat! They observed that American Indians, Africans, Inuit, and other groups were free from the diseases of civilization (including cancer), and the theory was that it was actually the meat that protected them (as opposed to replacing animal protein with other things, presumably carbs). Someone wrote a book about the high meat/lack of cancer connection; unfortunately, I can’t remember the name of this person, as I’d like to read the book! Funny though, how times have changed……
    In any case, it does seem inane that animal protein would kill us at a certain age (a very strong statement, which in itself makes me suspicious)- but on our 65th birthday we can now dance with glee and eat all the animal protein we want to because the so-called negative effect has reversed itself and turned positive. This just defies logic!

  19. avatar Mie says:


    “Without consistent recordings of IGF-1 levels over the years and without strict “ward” environments it is not possible to invoke a high protein/ IGF-1 / cancer link.”

    Of course it’s possible, just not with enough strength to challenge long, well-conducted trials. As for metabolic ward studies, their strength lies elsewhere since due to restrictions in n and length they cannot provide conclusive evidence on whether a given issue is of that much relevance in the real world and/or whether lifestyle interventions etc. etc. can address it or not.

    “The fact that this “study” has been reported worldwide is sad but then it fits right into the HCLF dietary pattern lauded by the pundits.”

    I suppose everything which YOU don’t want to hear fits right into that. HCLF diets can be low, moderate or high in protein, just like LCHF diets.

  20. avatar Mie says:


    “Protein is helpful to 65 year olds but detrimental to those who are 55? Highly unlikely. This screams ‘confounding factors’, not to mention ‘lying on the survey’!”

    See the “Discussion” part in the study. It’s not actually a miracle or even new information that things change when you get olders. Higher protein intake can reduce excessive weight loss due to the loss of muscle mass (which is very much a problem among the elderly) and also excessive drop in IFG-1 levels.

  21. avatar Tim C says:

    “In case you had missed this (unlikely) it was not just Valter D. Longo but three others of the authors (Sebastian Brandhorst, Priya Balasubramanian and Luigi Fontana) working for L-Nutra…”

    Holy Toledo! Talk about a conflict of interest (not to mention confirmation bias)

  22. avatar Tim C says:

    Thank you so much for your analysis. Researchers throw around fancy, sciency-sounding words, and get people to believe that the analysis they’ve provided is high quality, when in reality, it’s problematic.

    I am just coming to realize that almost everything I’ve learned about good nutrition in my life is really flawed, and the notion that “a calorie is a calorie” is woefully inadequate for describing macronutrients…especially as I begin to understand more about cellular respiration, and the interplay between the liver and cells.

    Do you think the term “protein” is too simplistic of a term, given the amount and impact of different amino acids?

  23. avatar Stipetic says:


    The authors stacked the deck in that study. First, they added methionine to the typically caseine-only protein in these rat chows, knowing full well that methionine has been shown to decrease longevity in rats. So, the rats who got the most protein also got the most methionine. Predictably, they died sooner. Secondly, the fat used in this study is not saturated or even trans, it is entirely soybean oil. No wonder those rats who ingested the most fat died earlier (and likely with moobs).

  24. avatar thing says:

    I hate journalists so much

  25. avatar Fiona says:

    Hi Zoe,

    Here in Australia we were bombarded with headlines about the risks of consuming a high protein diet due to another study conducted by the University of Sydney, published in the same ‘Cell Metabolism’ Journal as the one you have covered.

    This study claims to determine that a high carb, low protein diet is associated with a longer life span. I was wondering if you saw this and if so, what are your thoughts?


    Thank you for your insight much appreciated.

  26. avatar Vincent says:

    Doesn’t really stack up against the relatively high protein Mediterranean diet data, does it?

  27. avatar BillP says:

    “After finding no overall association, the researchers spotted a pattern with age and split the information into participants aged 50-65 and participants over 65. They then found (direct quotation again): “Among those ages 50–65, higher protein levels were linked to significantly increased risks… etc”

    Great analysis, Zoe!

    Protein is helpful to 65 year olds but detrimental to those who are 55? Highly unlikely. This screams ‘confounding factors’, not to mention ‘lying on the survey’!

  28. avatar John Kutlich says:

    Thanks Zoe for doing what we all knew you would – uncover the real story. Fantastic job and we can’t thank you enough! And thanks to FrankG for the additional info on the authors.
    BTW, protein shakes are not “invariably soy based”. Bodybuilders and strength athletes have been aware of the effects of soy for many years and the market responded a long time ago – most protein formulas targeting male athletes don’t have any soy.

  29. avatar Dina says:

    Thank you sooooo much! First for taking the time and reading the actual research and then writing this in laymen words.

  30. avatar FrankG says:

    Many Thanks for your work Zoë :-)

    “Call me suspicious, but I always check for conflicts of interest and the lead researcher, Dr Longo, has declared interests in (actually, he’s the founder of) L-Nutra – a company that makes ProLon™ – an entirely plant based meal replacement product.”

    In case you had missed this (unlikely) it was not just Valter D. Longo but three others of the authors (Sebastian Brandhorst, Priya Balasubramanian and Luigi Fontana) working for L-Nutra…


    …this may also speak to George Henderson’s insightful observations about the large number of contributors to such a shoddily executed piece of “science”.

  31. avatar Robin Willcourt says:

    This “study” invokes IGF-1 as the driver behind the cancer outcomes. Without consistent recordings of IGF-1 levels over the years and without strict “ward” environments it is not possible to invoke a high protein/ IGF-1 / cancer link. The assumptions are, to put it bluntly, as valid as those in a Hans Christian Andersen story. These folks have invoked a “mice and men” link that is pure homage to fairy tales.

    Worse, none of the protein percentages amount to anything like “high!” Indeed, the data indicate that a low protein intake is the problem, except that it is not possible to know with any assurance what the real protein intake was given the method of self-reporting. A high protein intake would be 2gm/kg body weight but this is far from what they understood to be high/low protein intake. In fact, 2 gm/kg is “optimal” for active people on high energy output days. For a 70 kg person this is about 700 gm of MEAT per day.

    The fact that this “study” has been reported worldwide is sad but then it fits right into the HCLF dietary pattern lauded by the pundits.

  32. avatar PhilT says:

    Bit odd that you quote two whey protein shake compositions ( *From milk ) and then go on to say “protein shakes are invariably soy(a) based” – more coffee required perhaps !

  33. avatar James says:

    Can you point to the studies that associate moobs with soy protein?

  34. avatar James says:

    I agree with your assertion that protein supplemts aren’t ‘food’, but for anyone trying to build lean body mass, they are certainly beneficial. Studies show that for optimal muscle protein synthesis you must ingest a relatively high (20-30g) amount of protein at once, and repeat this every few hours. The fact is, it isn’t easy, or cheap, to consume optimal amounts of protein for maximal MPS, through strictly whole, real foods.

  35. avatar W says:

    When I read the summary of this in the Washington Post, it sounded like “damned lies and statistics” from the get-go and I wondered who had taken the study apart first; then I thought to look for for the analysis here — thanks for this, Zoe!

    However, one thing I wish were always highlighted when discussing this sort of study is the validity of the study data itself. Almost all of these epidemiological studies rely on food frequency questionnaires that ask respondents to remember what they ate weeks, months, and in some cases, YEARS ago. Everyone should read Chris Masterjohn’s classic blog post in which (in the second half of the post) he discusses how the huge Nurses’ Health Study had a subgroup of nurses actually weigh and measure everything they ate for a week 4 times a year, and then reply to a food frequency questionnaire. Comparison between the weighed and measured data and the questionnaire data showed that the nurses hugely overestimated the vegetable servings they ate and hugely underestimated the amount of hamburgers they ate, among other things; see http://blog.cholesterol-and-health.com/2010/09/new-study-shows-that-lying-about-your.html

    Which raises the question of why researchers even bother to do these big “what did you eat and how sick did you get” kind of studies; they must have error margins big enough to to drive a truck — sorry, a lorry — through, even if the researchers aren’t up to some shady manipulation of the numbers, as you show that they were here.

    Gary Taubes pointed out a couple of years ago that epidemiology is being abused to “prove” things it simply can’t prove, and every trivial dietary correlation is being treated like the correlation between cigarettes and cancer — and none of them are; see http://garytaubes.com/2012/03/science-pseudoscience-nutritional-epidemiology-and-meat/

    By the way, to the Washington Post’s credit, they at least included this: “Marion Nestle, a nutrition expert and public-health professor at New York University, said the findings raise as many questions as they answer. She said they don’t amount to a convincing argument that too much protein consumption in middle age is directly linked to health problems later in life, while more protein in old age is protective. … ‘I’m also puzzled by the idea that there is a significant difference between the effects of protein from animal and vegetable sources,’ Nestle said. ‘Protein is not, and never has been, an issue in American diets, and the data presented in this study do not convince me to think otherwise.'” I wonder if the UK papers were as conscientious in giving space to a contrary viewpoint?

  36. avatar lol lol lol lol says:

    Q: On what planet does a human diet deriving 20% of total energy from protein = a “high-protein” diet?

    A: On Planet Wacko, where—
    Consuming more than 1/2 drink/day makes one a “heavy drinker”…
    Having more than 2 sexual partners in a lifetime makes one “promiscuous”…
    Walking more than 400 meters/day makes one “highly active”…

  37. avatar Sarah says:

    Great article!

    It’s also worth noting that of participants with a ‘history of diabetes’, 28% were in the ‘high’ categories, versus 2% in the ‘low’. Of those who had changed their diets, 23% were now in the ‘high’ group vs 4% in the ‘low’. It would not be surprising if those with diabetes consumed a higher percentage of their intake from protein due to the constraints of attempting to limit GI foods and refined carbohydrates. This could imply that people with a history of diabetes may have a disproportionate representation

    Similarly, of those who had attempted to lose weight 21% were in the ‘high’ vs 7% in ‘low’. Therefore it is possible that yo-yo dieters or those who are encouraged to lose weight due to a history of weight related disease in their family (such as diabetes) are more likely to be present in the ‘high’ catergory rather than the ‘low’.

    Therefore if more people with a personal history of diabetes (as is reported) or if the above analysis on the probability of family history of diabetes holds true, we really shouldn’t be all the surprised that those people are more likely to subsequently die of diabetes. The actually death rates from any cause where also identical for both groups (42.9%) so ultimately something got them within the time frame, it’s a shame we don’t have the data into ages of death.

    A final interesting point is that these were self-reported and done so to a dietician. We now know the prevalence of under reporting of food intake, particularly for ‘unhealthy’ things. So it seems possible that the unreported food is more likely to be in the form of high carb/fat foods (larger bowls of cereal, handfuls of crisps, slightly more alcohol) rather than the form of animal protein. People are unlikely to forget that had chicken for dinner or to be embarrassed to report it to a dietician. This would obviously particularly skew the report, slightly (though protein calories were still ~1/3 greater than average). It’s particularly interesting to note that the ‘high protein’ group reported the lowest total calorie intake of <1,600kcal, whereas the 'low protein' group reported the highest ~2,000kcal and 15% also admitted to this being less than they usual ate. Seems to tally slightly more honestly with the current obesity rates…

    Lies, damn lies & statistics.

  38. avatar George Henderson says:

    Fantastic analysis Zoe.
    A couple of additional things struck me about the papers:
    1) the incredible number of contributing authors. This sort of massing of scientists is not normal – it is something usually seen on manifestos. It is very unlikely that this many people agreed with the conclusions on the thin science grounds, which makes it likely that they have gathered for some other reason – a common belief system (such as veganism), or an interest in promoting protein restriction as cancer therapy. Which takes us to:
    2) The mouse paper. Protein restriction is a legitimate cancer therapy (at least in mice). Of course what inhibits an existing cancer may not be what would have prevented it from starting in the first place (radiation both causes and inhibits cancer). But look at what (I’m told, correct this if wrong or incomplete) these mice ate: the protein (the variable item) was casein, plus DL-methionine. D-methionine is a rare amino acid, non-essential, not usually toxic to mice, but, if the mouse has cancer, who knows? It’s in every experimental diet, for some reason. Certainly not something recommended for human consumption. The high-animal protein mice ate more of this. Soy oil, grain starch, sugar. Added vitamins and minerals. Colouring.
    Also, where was the age difference in the mice? All that study shows is that protein restriction is a cancer therapy (one of many, humans might prefer ketosis, radiation, chemotherapy) but we knew that already.
    Usually cancer is more prevalent in ageing populations. It’s nice to think that animal protein reverses this trend, but I wonder how many other nutrients were separated in the data. Refined starch, sugar, and polyunsaturated oil are all things that should have been adjusted for separately. We’ll see if they were.

  39. avatar SpittinChips says:

    D – I used to have at least one protein shake per day, usually with lunch after a gym session. It confused me that I’d get a sugar crash an hour or so later when I was eating pretty much zero carbs.

    I had no idea whey protein was so insulinogenic – http://suppversity.blogspot.com.au/2012/06/whey-more-insulinogenic-than-white.html

    Or it could have been that I was just eating way (whey?) too much protein for my body’s requirements.

    No more protein shakes, no more mid afternoon yawn-fest. And my muscles haven’t fallen off, which is a relief.

  40. avatar Dan connelly says:

    As you note, there’s all sorts of confounding factors. One is meat-based proteins tend to come with animal-based fats, and there’s excellent reason to believe animal fats may be an issue, especially given the way our animal products are prepared.

  41. avatar Jimmy the chin says:

    Great piece. I’m sharing.

    The whole think just doesn’t add up and when you said he owns that company then it becomes clear. Sadly vegetarians will be all over this and I’ll have to listen to people telling me how I’m going to die from my meat consumption because they only read the headline.

    Tell that to jon Andersen who I blogged about at strengthandvirility.com, he lives off nothing but grass fed beef. He looks a hell of a lot better than any vegetarians I know.

    ….. I’m not trying to bash veggies but they seem to be obsessed with converting the planet to their way of eating. At least there will be more meat available for me. :)

  42. avatar Carolyn says:

    Well said and explained Zoe!

  43. avatar M B says:

    This doesn’t apply to the mouse data, but the raw survey data used for the study are available here:


    While I certainly agree with your assessment of the reporting and the headlines, I do think care should be taken not to conflate that with the study itself. The study does not mention the risk of smoking at all. The quote in the articles does come from Dr. Longo, however, and it first appears in the USC press release about the study.


    Frankly, this press release is horrendous and it should probably be the target of your attack. As for the meat and cheese statements, those also comes primarily from the press release.

    I still suspect that the animal vs plant protein conclusion will hold up in an independent analysis of the data– at least well enough to merit further research. While this study does not distinguish between high-and low quality protein sources, it is worth noting that it never claims to. A comparison of the effects of high and low-quality plant and animal protein sources is out of the scope of the study (and probably not possible with the existing data).

    While the conclusions in the study are not the same as those in the press release and subsequent articles, I have a harder time disregarding the study’s conclusions based on Dr. Longo’s disclosure of interest than you do. I’d be very interested to see somebody else run the numbers, as I’m not qualified to do so myself. I know enough to know that I’m out of my depth here :)

    • avatar Zoë says:

      Hi MB – good point on the distinction between the press release and the study. The press release has become the gateway to the media unfortunately and researcher ethics are being compromised for researcher egos in this respect. The only thing better than a published study is a study that hits the headlines and Longo’s reference to smoking achieved that – completely inappropriately from what I’ve seen in the study.

      I also want to run the numbers – I’ve asked for the raw data on deaths and subjects by condition, by age, by protein intake. As per my p.s. – I suspect the majority of deaths are in the over 65s – where higher protein intake is associated with lower mortality and the smaller number of deaths in the 50-65 group may explain some of the large confidence intervals and relative risks.

      Watch this space!
      Very best wishes – Zoe

  44. avatar D says:

    Hey Zoe, in the conclusion section of this analysis, you state that extra protein isn’t bad, as long as it comes from natural foods and not shakes. What’s wrong with shakes? Is the protein of lower quality or something? Or is it that the shakes come full with a variety of other stuff that aren’t as good for you?

    • avatar Zoë says:

      Hi D – I advise eating food – we shouldn’t need to call it real food. This is a protein shake (an example):

      Undenatured Whey Protein Concentrate*, Cocoa Powder (chocolate smooth, chocolate caramel and mocha flavours only), Flavouring (flavoured options only), Citric Acid (raspberry, vanilla and raspberry, strawberry jam roly poly & summer fruit flavours only), Malt Extract (latte, toffee, chocolate caramel & banoffee flavours only), Emulsifier (Soy Lecithin), Malic Acid (choc coconut flavour only), Sweetener (Sucralose® [flavoured options only]), Colourings (Beetroot Red [raspberry, vanilla and raspberry, strawberry cream, strawberry jam roly poly, summer fruits and rhubarb & custard flavours only], Anthocyanin [raspberry flavour only], Curcumin [ banana & summer fruits flavours only], Caramel [choc coconut and sticky toffee pudding flavours only]). *From Milk

      Natural Flavours Undenatured Whey Protein Concentrate*, Cocoa Powder (natural chocolate flavour only), Natural Flavouring (natural options only), Colourings (Beetroot Red [natural strawberry flavour only], Curcumin [natural banana flavour only], Sweetener (Sucralose®), Emulsifier (Soy Lecithin). *From Milk

      That’s not food!

      Plus protein shakes have an unnatural level of protein – real food has protein in natural proportion with carbs or fats (sometimes both). Too much protein is bad for your liver and can deplete vitamin A.
      Plus protein shakes are invariably soy(a) based – containing plant oestrogen – think “The pill”; think “moobs” and don’t ingest!
      Is that enough?! ;-)
      Best wishes – Zoe

  45. avatar Jennifer Scott says:

    Thanks Zoe for your most sensible article, as always.
    As a 66 year old, I have finally returned to the sensible diet of my 1950s childhood, and wish I had never been influenced by the barmy ‘researchers’ during the intervening years.
    So….moderation in all things.
    Quality animal proteins, known as 1st class in days gone by.
    Mixed fats from all natural sources…..sats, MCTs, and a smattering of PUFAs from seeds and a few nuts.
    But, admittedly, less carbs than I would have consumed….because even fresh fruits and grains have been so modified, that they are no longer a reliable source of anything!
    But, I now enjoy quality chocolate, which was not readably available then, plus a glass of red wine, which I have come to late in life.
    It has taken me a year to sort through the dreadful mess that our food industry has got us into….but being retired, I have the time, and inclination, to get to grips with it all…much to the advantage of my health status.

  46. avatar Dave says:

    Isn`t research wonderful. I follow ( since 2007 ) a lo-carb regime due to t2 and at the time being very close to 20st. I lost a shed load of weight and all of a sudden felt and was a whole lot better. At every check-up I got a well done because the numbers were pretty good. What the nurse/GP wasn’t interested in was my diet. Oh well if it works for you!!.
    With the current hoo hah about the NHS flogging patient data in my particular case it would be something of a non runner because all they will get is medication history but nothing about what I eat. The fact that I showed improvement with a condition that is generally thought to deteriorate would be attributed to the wonder of drugs not life style or diet.

  47. avatar Dave says:

    All of this is easily explained by digestible/metabolizable energy. The high animal protein diets will have more available calories versus plant protein only, or a plant/animal combination, due to the ease with which we digest animal products and the fat content. More calories mean more likely to be overweight, which means more likely to be diabetic, and on…..
    This is probably why the elderly group (> 65) did well with higher protein. They eat less (total volume) than younger people, consume fewer calories, and so, a protein-dense diet is beneficial for them.
    So, the protein is beneficial, and the excess calories is the real problem.
    I hate to say it, but calories in, calories out……

  48. avatar Etienne Marais says:

    Thanks for a great analysis ! Amazing you the media pick up on stuff like this !!

  49. avatar Perry Poole says:

    When I saw the headline in the newspaper this morning, I wondered how long it would be before we got the truth from you Zoe! You didn’t let us down… Thank you!

  50. avatar Tom Welsh says:

    “Dr Longo, has declared interests in (actually, he’s the founder of) L-Nutra – a company that makes ProLon™ – an entirely plant based meal replacement product.”


    As far as I’m concerned I forgot about the whole farrago of nonsense as soon as I read those words. Pathetically transparent.

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