Is It Dangerous to Eat Meat Before Age 65?

Meat the American way. Not in the picture: the drink.

Meat the American way. Not in the picture: the drink.

Is it dangerous to eat meat if you’re between 55 and 65? Will eating lots of meat then suddenly become healthful after you turn 65?

This is the somewhat confusing conclusion that some researchers drew from a new American questionnaire study:

As usual, we have to take sensational headlines with a substantial pinch of salt. This was just a food questionnaire that was sent to some thousand Americans, and the researchers then looked at statistical associations with diseases.

Uncertain Association

As regular readers know, one can’t prove causation by correlating statistics from questionnaire studies. Only ignorant or sensationalism-driven journalists believe so. Unfortunately these two groups seem to constitute the vast majority of all journalists.

On subsequent examination, it turns out that at least 80% of similar findings in uncertain questionnaires are incorrect – see table 4 in the excellent review Why Most Published Research Findings are False.

So a more scientifically correct headline would be “There is a 20 percent chance that meat quadruples the risk of cancer for people under the age of 65 and reduces the risk for older people.” Not as enticing.

The statistical correlation between meat-eating and disease in people under 65 in the U.S. may just as well be due to the fact that meat consumption there is associated with eating junk food, smoking, lack of exercise, less vegetables and in principal any unhealthful lifestyle you can think of.

What, in all of these unhealthful lifestyles, is the cause of disease ? Statistics cannot prove this.

IGF-1 and cancer

Therefore, there are good reasons to ignore the study. But I guess that there’s still some truth behind it. Scientists report that protein (high-quality animal protein in particular) may raise levels of the hormone IGF-1, which stimulates cell division. High levels of IGF-1 may in the long run increase the risk of cancer.

What they don’t mention is that carbohydrates also increase levels of IGF-1, at least as much. Particularly bad carbohydrates in greater quantities radically raise IGF-1 levels. The only thing you can eat that doesn’t significantly increase levels of IGF-1 is fat.

The logical conclusion is that any variation of a low-carbohydrate diet with moderate amounts of protein (and enough fat) is the healthiest in the long run – at least to keep IGF-1 low while still feeling great. How much protein? The amount you need to feel good, feel full and stay strong and healthy. What is this concept called? LCHF.

The really ambitious may add intermittent fasting for maximum effect.

More

Do Unhealthy Meat Eaters Live Shorter Lives?

Low Carb Wins Yet Another Study

Swedish Tabloid Warns of “Low-Carb Cancer”

48 comments

Top comments

  1. murray
    Good point Wade. As Zoe Harcombe observes:

    "The study claims to have adjusted for protein in general vs. animal protein to conclude that animal protein is the harmful factor and not protein per se. 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."

    Read more →
  2. murray
    Yes, Frank, the 51% calories from carbs leapt out to me as well. Carbs over 40% triggers genes for systemic inflammation, which promotes cancer, and elevated glucose is fuel for cancer. So the sample group was likely getting cancerous cells regularly (which a healthy metabolism would usually kill off through immune response), but with high IGF-1 and with high blood glucose surges from 51% carbs, the cancer cells may proliferate faster than the glucose-impaired immune system could handle. Given the virtual absence of cancer in high-meat cultures, like Inuit and Masai, the obvious solution is to increase fat and reduce carbs.

    Cynthia Kenyon's work on longevity found both insulin and IGF-1 had similar effect regarding deterioration with age. She revised her own diet to reduce insulin and IGF-1 .... to LCHF. Plenty of cheese.

    Read more →

All comments

  1. charles grashow
    Did you read the study itself or just the articles about the study??

    Here's the full study

    http://www.cell.com/cell-metabolism/abstract/S1550-4131%2814%2900062-...

    "The study population included 6,381 adults ages 50 and over from NHANES III, a nationally representative, cross-sectional study. Our analytic sample had a mean age of 65 years and is representative of the United States population in ethnicity, education, and health characteristics (Table S1).

    On average, subjects consumed 1,823 calories, of which the majority came from carbohydrates (51%), followed by fat (33%) and protein (16%), with most of it (11%) derived from animal protein. The percent of calorie intake from protein was used to categorize subjects into a high protein group (20% or more of calories from proteins), a moderate protein group (10%–19% of calories from proteins), and a low protein group (less than 10% of calories from proteins).

    Mortality follow-up was available for all NHANES III participants through linkage with the National Death Index up until 2006 (DHHS, 2001). This provided the timing and cause of death. The follow-up period for mortality covered 83,308 total person-years over 18 years, with 40% overall mortality, 19% cardiovascular disease (CVD) mortality, 10% cancer mortality, and about 1% diabetes mortality."

    "Overall, our human and animal studies indicate that a low protein diet during middle age is likely to be beneficial for the prevention of cancer, overall mortality, and possibly diabetes through a process that may involve, at least in part, regulation of circulating IGF-1 and possibly insulin levels. In agreement with other epidemiological and animal studies (Estruch et al., 2013,Linos and Willett, 2007,Michaud et al., 2001,Willett, 2006), our findings suggest that a diet in which plant-based nutrients represent the majority of the food intake is likely to maximize health benefits in all age groups. However, we propose that up to age 65 and possibly 70, depending on health status, the 0.7 to 0.8 g of proteins/kg of body weight/day reported by the Food and Nutrition Board of the Institute of Medicine, currently viewed as a minimum requirement, should be recommended instead of the 1.0–1.3 g grams of proteins/kg of body weight/day consumed by adults ages 19–70 (Fulgoni, 2008). We also propose that at older ages, it may be important to avoid low protein intake and gradually adopt a moderate to high protein, preferably mostly plant-based consumption to allow the maintenance of a healthy weight and protection from frailty (Bartali et al., 2006,Ferrucci et al., 2003,Kobayashi et al., 2013)."

    Supplemental info
    http://download.cell.com/cell-metabolism/mmcs/journals/1550-4131/PIIS...

    There's also this
    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2989112/?report=classic

    Conclusion

    "A low-carbohydrate diet based on animal sources was associated with higher all-cause mortality in both men and women, whereas a vegetable-based low-carbohydrate diet was associated with lower all-cause and cardiovascular disease mortality rates."

    Reply: #13
  2. FrankG
    Of mice and men... LOL

    "Here, we combined an epidemiological study of 6,381 US men and women aged 50 and above from NHANES III, the only nationally representative dietary survey in the United States, with mouse and cellular studies to understand the link between the level and source of proteins and amino acids, aging, diseases, and mortality."

    Study says "dietary survey"... so NOT an RCT then...? I thought you subscribed to higher standards of research Charles?

    Telegraph article says "Nutritional advice has traditionally focused on cutting down on fat, sugar and salt. The World Health Organisation will announce a consultation today suggesting that guidelines on sugar consumption should be lowered, but there have few warnings about excess protein."

    Call me skeptical but the timing of this report could not be better from the point of view of those with a ve$ted interest in the current $tatus quo :-P

    But, as it seems to need constant repetition for some... LCHF stands for low-carb, high-FAT not high-PROTEIN

  3. Gretchen
    The illlustration you chose for this story implies that "high protein" is synonymous with lots of multibun burgers, which are usually accompanied by lots of fries and a soda. I suspect researchers had similar unconscious biases.
  4. FrankG
    Indeed Gretchen, the study states...

    "The study population included 6,381 adults ages 50 and over from NHANES III, a nationally representative, cross-sectional study. Our analytic sample had a mean age of 65 years and is representative of the United States population in ethnicity, education, and health characteristics (Table S1).

    On average, subjects consumed 1,823 calories, of which the majority came from carbohydrates (51%), followed by fat (33%) and protein (16%), with most of it (11%) derived from animal protein."

    51% of energy from carbs... but no question it's the protein that's doin' 'em in! :-P

    So for "protein" we can for sure infer: burgers with buns (both probably loaded with HFCS), special sauce ketchup, fries and soda etc...

    Of course though, as this was based on nothing more substantial than food surveys, we could play around all day with statistics and pick meaningless but significant sounding numbers out of thin air.

    As they say in software engineering, regarding data-manipulation, "garbage in, garbage out" :-P

  5. murray
    I have found it fairly simple to regulate the amount of meat. If I have too much, then my morning blood sugar then next day is above 4.7 mmol/L and ketones are lower than usual (below 1.0 mmol/L).

    These comments by Professor Sanders are helpful. It seems remarkable that the study would not control for variables such as smoking.

    Prof Tom Sanders, Head of the Nutritional Sciences Research Division, King’s College London, said:

    “The headline of the press release from the University of Southern California is running ahead of the evidence, and the comparison with smoking is really unwarranted in terms of the relative risks and the certainty of the adverse effects of smoking. The study shows a relationship with growth factor IGF-1 and cancer risk which is already known. However, the relationship between IGF-1 levels and protein intake is far more tenuous in humans. Cross-sectional data i.e. omnivores vs vegans suggest animal protein to be associated with increased IGF-1 levels but there is a lack of evidence from controlled feed studies to show that IGF-1 levels fall when animal protein intake is restricted. Much of the supporting work is based on studies in mice not humans. Dietary guidelines should not be based on animal experiments.

    “Although the follow-up on the NHANES survey* shows that those with the highest reported protein intake were at greater risk of all-cause mortality, it fails to adjust for other confounding factors such as socioeconomic status, smoking, and obesity. The sample size is also modest at 6381, compared with over 448,568 in the European Prospective Investigation into Cancer which only found a weak association (14% increase in risk of mortality with red meat consumption, which was more consistent for processed meat (11% increase in risk)). The European data suggest a much smaller effect than the 74% increased risk claimed in this paper.

    “Also, the study does not control for the overall balance of the diet. People who eat large amounts of animal proteins often have other aspects of their diet which are imbalanced such as low intakes of fruit and vegetables. I think the next step would be to show that changing protein intake in the range of normal human intakes influences IGF-1 levels. IGF-1 levels may well be programmed in early development and dietary protein intake in adult life may well be less important in later life. This would be consistent with the observation that accelerated growth in childhood is associated with increased height and a high risk of cancer in later life.”

  6. murray
    Yes, Frank, the 51% calories from carbs leapt out to me as well. Carbs over 40% triggers genes for systemic inflammation, which promotes cancer, and elevated glucose is fuel for cancer. So the sample group was likely getting cancerous cells regularly (which a healthy metabolism would usually kill off through immune response), but with high IGF-1 and with high blood glucose surges from 51% carbs, the cancer cells may proliferate faster than the glucose-impaired immune system could handle. Given the virtual absence of cancer in high-meat cultures, like Inuit and Masai, the obvious solution is to increase fat and reduce carbs.

    Cynthia Kenyon's work on longevity found both insulin and IGF-1 had similar effect regarding deterioration with age. She revised her own diet to reduce insulin and IGF-1 .... to LCHF. Plenty of cheese.

  7. paulc
    "On average, subjects consumed 1,823 calories, of which the majority came from carbohydrates (51%), followed by fat (33%) and protein (16%), with most of it (11%) derived from animal protein. The percent of calorie intake from protein was used to categorize subjects into a high protein group (20% or more of calories from proteins), a moderate protein group (10%–19% of calories from proteins), and a low protein group (less than 10% of calories from proteins)."

    so basically it was a high-carb western diet with some slight changes in the protein percentages...

    this diet is NOT high protein or high fat... and the way it is being used to demonise the Atkins and Paleo diets is nothing short of a complete travesty...

    Reply: #12
  8. Paul the rat
    I say what I see 'from my chair': medical research, especially regarding nutrition, is 95% taken over by pharmaceutical companies/sugar industry money. They decide where research grant money go, who is on the editorial board of scientific journals (including prestigious once like Cell) et cetera et cetera. (5% sneaks through, but is dismissed by mainstream).

    Regarding this paper - it is not science, as I pointed out on the other post - carbohydrates are the player here not protein or fat. Besides in what form this animal protein was consumed - salami sausages?, processed meat with additives? or it was raw meat slowly cooked in water/lard?

    Just listen to your own bodies folks.

    Reply: #9
  9. murray
    The paper seems to come from Southern California. California heavily promotes vegetables and fruit. If this was government-funded research, you can understand the spin and decisions such as not controlling for well-established confounding variables such as smoking. Dr. Catherine Shanahan in her book Deep Nutrition reports on her experience with this funding bias in her efforts to get research funding in California.
  10. mezzo
    There may be people out there who eat "too much meat" - however much that may be. I find that I can only eat a certain amount and then my body says "enough". After that I don't fancy more of it even if it is the juiciest of juicy steaks. This actually goes for all kinds of meat, fish as well as eggs and cheese. With protein there appears to be a very clear "stop"-signal. There never was with pasta or pizza.
  11. Ted Hutchinson
    Bear in mind this is NHANES data and that has been shown not to add up
    Colpo has a rant about it here.
    Why You Can’t Trust NHANES (or Gary Taubes & Robert Lustig) to Accurately Report Calorie, Carbohydrate & Fat Intake Trends
  12. FrankG
    So based on just these few posts, I have to ask Charles, did YOU actually READ the study, or did you unquestioningly accept the conclusions of its authors at face value?
  13. Gretchen
    @ Frank Or they could have been eating "healthy" skinless chicken and a ton of "healthy whole grains" with margarine. Plus something fatty for dessert on the theory that they'd been so virtuous with the rest of the meal.
    Reply: #15
  14. FrankG
    Just the average of "1,823 calories" a day for the USA, ought to start cautionary bells ringing about how reliable this data could possibly be... but they sure can dress it up real purty like with statistics :-)
    Reply: #22
  15. Paul the rat
    I would like to point out that Levine et al. for their mice studies used casein protein for diet containing 18% E as protein and Soy protein for diet containing 4-18% E- unbelievable!!!. Although casein is used as protein source in rodents experimental diets, it is also well known that mice physiology respond differently to casein (increased inflammation) in comparison to, say, egg-white protein (being a rodent I know).

    I simply can not believe that Cell published such a paper - unbelievable !!!. This only illustrates how powerful pharma/sugar money is.

    Reply: #17
  16. Ted Hutchinson
    Nice recent paper here showing the change from Casein to Whey protein makes a difference to a high fat diet
    Protein Quality and the Protein to Carbohydrate Ratio within a High Fat Diet Influences Energy Balance and the Gut Microbiota
    Reply: #18
  17. Paul the rat
    Thank you Ted, I am aware of this work.
    (I need to go and feed my rats now)
  18. Wade Henderson
    Simply amazing. Never underestimate the ability of the human mind to twist, turn and rearrange the information such that it fits, explains, or supports one's prior set of firmly held beliefs.
    Replies: #20, #24
  19. murray
    Good point Wade. As Zoe Harcombe observes:

    "The study claims to have adjusted for protein in general vs. animal protein to conclude that animal protein is the harmful factor and not protein per se. 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."

  20. LCHF_Graham
    @Paul

    What was I saying about 'crap' being published in the 'scientific' literature on the other thread? It happens all the including in 'Nature' and 'Science'.

    This paper is another example of data dredging - very poorly done and add to that the lazy journalism and we have a 'shock' headline that's effectively meaningless.

  21. LCHF_Graham
    @FrankG

    Yeah the average American only eats 1800 kcal or so. In other news fairies dance at the bottom of my garden and the moon is made from 'evil' cheese.

  22. Nancy
    I agree with Ms Mezzo. I can eat pizza and cake all day every day. The LCHF way of eating causes me to naturally have a starting and stopping point, creates a natural appetite. It's better for me in many ways and I was a vegan/vegetarian for lots of years.
  23. Paul the rat
    @ Wade Henderson,

    how about: to think, reason, critically weigh evidence and infer (more so if this is supported by personal experience)

    Please show me at which point I, or others here: "..twist turn and rearrange..". I honestly want to know - if you show me my mistakes I will acknowledge them.

    I am waiting….

    Reply: #29
  24. LCHF_Graham
    Jack Winkler, former professor of nutrition policy at Metropolitan University, explains: "They did a correlation between the national diet survey in the United States (NHANES), and some data on death by disease. They linked it up, then alleged that protein caused death. Now, NHANES suffers from what all diet surveys suffer, namely: you ask people what they eat and what you get back is lies. People respond normatively. They put themselves in the best possible light. They're not harmful, deceitful lies. In the case of the British survey, people underreport how much they eat by 25% and adolescents by 30%. Underreporting they call it, but in plain English, it's lies."

    A study has just been published on what's wrong with NHANES, which concludes: "Across the 39-year history of the NHANES, EI [Employment Insurance] data on the majority of respondents (67.3% of women and 58.7% of men) was not physiologically plausible." In plain English, if they really ate what they said they'd eaten, they would no longer be alive. In two-thirds of cases.

    Winkler continues: "The practical consequence for the protein story is that you've got a correlation between food intake and disease, but the food intake data is so poor that any correlation is suspect. Academics sit in front of a computer screen and do data analysis. But they never question the quality of the primary data. I'm not being rude, but my attitude towards that study is contempt."

    What does all that mean? Ignore experts? Listen to them selectively, according to your mood? No: be as you were. Forget protein. Concentrate on sugar. Winkler concludes, trenchantly: "Sugar is the issue of 2014. It's going to continue to be the issue of 2014. We should talk about why taxes will not work. We should talk about what we ought to do instead."

    Read the whole article at http://www.theguardian.com/lifeandstyle/2014/mar/05/cant-eat-animal-p...

    I think the word contempt about sums up what I feel about the 'science' in this study too.

    Reply: #26
  25. murray
    Yes, I put little reliance on food survey data. Generally I look for metabolic pathways and then see if more controlled trials bear out the metabolics. Just because a metabolic path exists, does not mean it has practical significance in the range of behaviour. For example, Lustig in Fat Chance sets out all sorts of metabolic responses to fat loss that suggest subcutaneous fat cannot be shed long-term and the metabolics are tilted to return to a set point. But such feedback mechanism may exist without always outweighing other metabolic factors, and a new stable attractor state may be achievable. And experience bears this out--some people, including me, lose subcutaneous fat and don't grow it back. So tyhere may well be metabolic processes A1, A2, ..., An that pull us back, but equally B1, B2, ...Bm pull to a new state, so whether one set prevails or another depends on experience and predispositions.

    Regarding cancer, I find Seyfried's metabolic theory more convincing. In this model, the level of IGF-1 sounds plausible as a downstream factor to facilitate an existing cancer, but where is the link between the protein source and IGF-1 in humans? I've only seen studies with mice. Sure casein raises IGF-1 in mice, but where in human studies? The researchers I spoke to say IGF-1 in humans more or less tracks insulin. Thus Cynthia Kenyon who seeks to reduce insulin and IGF-1 eats cheese and meat (and low-carb, obviously). So the metabolic plausibility of the study has not been establish so far as I can see.

    The reciprocal differences as cancer rate a reported meat and high protein percentages at different ages suggests it is more lifestyle being indicated, or even more likely, that people self-report food differently as they age and their outlook on life and health evolves. This study should be sent to the psychology department, not the health and nutrition sciences department.

  26. LCHF_Graham
    Personally the only thing this study "indicates" is the idiocy/intellectual dishonesty/bias of those that wrote it and the shocking low editorial standards at the journal which published it.

    As science it's 100% junk. I know good biological science when I see it. And this is garbage. It's part of the 'publish any old rubbish or your career will die' game. Better to publish nonsense than not publish at all is sadly the state of science across most areas.

  27. Eric Anderson
    SAD, SAD, SAD
    Yes; the standard american diet. SAD includes many foods in quantities that are not health foods. Sugar, refined carbohydrates, and carbohydrates in general. FAT you say! It depends on what fat. Seed and nut oils like corn, soy, and crisco shortening account for most fat in the average american diet. When you have not been able to seperate sugars, refined carbs, and types/sources of fat then what solid conclusions can you reach? Not much I m afraid.

    Even ketogenic diets need to be viewed with a skeptical eye. How much protein? What source? How much fat? What source? Are all calories and carbohydrates accouned for? Down to trace amounts in cream, eggs, an nuts? What areinsulin levels? Glucose levels, Blood ketone levels? Without such information the conclusions may or may not be missleading.

  28. Wade Henderson
    Oh Paul the rat, you're so sensitive.

    If you look at the study....

    http://download.cell.com/cell-metabolism/pdf/PIIS155041311400062X.pdf...

    you see that 4 of the authors are also associated with the company that sells products to extend life... longevity.

    http://www.l-nutra.com/index.php/about/team

    Now Paul, don't you feel silly thinking I was questioning your's and other's lack of objectivity when it comes to such studies?

    I know you only see the truth in these matters. Never bringing any pre-determined opinion that would cause any bias.

    Reply: #34
  29. Robin Willcourt
    This is not a study! That insults the concept of "study." It is simply musings on poorly collected data with lots of assumptions and inferences.

    IGF-1 is almost always a red herring when invoked in "cancer" stats because it can be associated -- remember, correlation is NOT causation-- with inflammatory changes; this is the normal response in healing. Remember, cops at the accident site are NOT the cause of the accident (well usually).

    The assumption that hGH and/or IGF-1 cause cancer has not been proven. More correlation assumptions.
    The only likely way I can see that this mechanism could work, is to have telomeres so shortened by repeated cell division under hGH stimulation that cancer might occur as a result. This, too has not been proven.

    In any case, I doubt that they know what a normal IGF-1 is. You have to look at lots of 25 yo to get to know these numbers.

    How this crap got published is beyond me.

  30. Daniel Ferreira
    You know what,

    for every animal a vegan wont eat, I'll eat 3.

    A nice Plant base diet with LOTS of animal Protein & NATURAL fats is really the optimum diet there is. Its been proven already and it makes sense.

  31. PhilT
    In the supplementary material the study quite clearly states "Using Cox Proportional Hazard models we found no association between protein consumption and either all-cause, CVD, or cancer mortality (Table S2). However, high and moderate protein consumption were positively associated with diabetes-related mortality. One explanation is that diabetes may be more prevalent in these groups, possibly because of a switch to a higher protein, lower fat, and lower carbohydrate intake following a diabetes diagnosis."

    http://download.cell.com/cell-metabolism/mmcs/journals/1550-4131/PIIS...

    The low protein group was tiny, the high protein group over twice as big but still 1/4 the size of the "normal" protein centre third.

  32. Michelle
    I'm not a scientist but I have experimented on myself and my partner (ha!) and this is what we have found:

    Not matter how hungry we are we cannot eat more meat than our bodies want. I have found that we eat less meat than we did on the so called SAD diet. However, you can only 'hear' your body tell you this, if you have your insulin levels under control.

    I have heard many on this site and others declare that the LCHF diet seems to be a cure all; I'm beginning to agree.

  33. Paul the rat
    @ Wade Henderson

    I am still waiting for you to show me where do I bring pre-determined opinion, which causes bias or where do I twist, turn and rearrange

  34. Paul the rat
    Enjoy your rolled uncut oats Wade
    (I am thinking how can I twist and turn these results)

    Cell Death Dis. 2014 Feb 20;5:e1074. doi: 10.1038/cddis.2014.52.
    Cell differentiation versus cell death: extracellular glucose is a key determinant of cell fate following oxidative stress exposure.
    Poulsen RC, Knowles HJ, Carr AJ, Hulley PA.
    Author information

    Abstract
    Cells, particularly mechano-sensitive musculoskeletal cells such as tenocytes, routinely encounter oxidative stress. Oxidative stress can not only stimulate tissue repair, but also cause damage leading to tissue degeneration. As diabetes is associated with increased oxidative damage as well as increased risk of tendon degeneration, the aim of this study was to determine if extracellular glucose levels alter the response of tendon cells to oxidative stress. Primary human tenocytes were cultured in either high (17.5 mM) or low (5 mM) glucose and treated with 100 μM hydrogen peroxide. In low glucose, peroxide-treated cells remained fully viable and collagen synthesis was increased, suggesting an anabolic response. In high glucose, however, peroxide treatment led to increased bim-mediated apoptosis. The activities of both forkhead box O (FOXO1) and p53 were required for upregulation of bim RNA expression in high glucose. We found that both p53-mediated inhibition of the bim repressor micro RNA (miR17-92) and FOXO1-mediated upregulation of bim transcription were required to permit accumulation of bim RNA. High glucose coupled with oxidative stress resulted in upregulation of miR28-5p, which directly inhibited expression of the p53 deacetylase sirtuin 3, resulting in increased levels of acetylated p53. In peroxide-treated cells in both high and low glucose, protein levels of acetylated FOXO1 as well as HIF1α (hypoxia-inducible factor 1α) were increased. However, under low-glucose conditions, peroxide treatment resulted in activation of p38, which inhibited FOXO1-mediated but promoted HIF1α-mediated transcriptional activity. In low glucose, HIF1α upregulated expression of sox9 and scleraxis, two critical transcription factors involved in establishing the tenocyte phenotype, and increased collagen synthesis.

    The switch from FOXO1-mediated (proapoptosis) to HIF1α-mediated (prodifferentiation) transcription occurred at an extracellular glucose concentration of 7 mM, a concentration equivalent to the maximum normal blood glucose concentration.

    Extracellular glucose has a profound effect on the cellular response to oxidative stress. A level of oxidative stress normally anabolic may be pathological in high glucose.

    Reply: #39
  35. FrankG
    For any that have not yet read the Zoë Harcombe analysis of this "study", I highly recommend it...

    http://www.zoeharcombe.com/2014/03/animal-protein-as-bad-as-smoking/

    “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.

    And (as Wade noted above) it was not just Valter D. Longo but three others of the authors -- Sebastian Brandhorst, Priya Balasubramanian and Luigi Fontana -- also working for L-Nutra…

    http://www.l-nutra.com/index.php/about/team

  36. FrankG
    WHO | Draft Guideline: Sugars intake for adults and children

    http://www.who.int/nutrition/sugars_public_consultation/en/

    Online public consultation open: 5 to 31 March 2014

  37. murray
    "The switch from FOXO1-mediated (proapoptosis) to HIF1α-mediated (prodifferentiation) transcription occurred at an extracellular glucose concentration of 7 mM, a concentration equivalent to the maximum normal blood glucose concentration."

    Paul, perhaps I am a bit slow here, but switching "from" FOXO1-mediated (proapoptosis) "to" HIF1α-mediated (prodifferentiation) transcription occurred at an extracellular glucose concentration of 7 mM, presumably means as blood sugar FALLS below 7mM. Have I got that right?

    Looks like drinking sugary sports drinks or juice during exercise is not an ideal training strategy. Little wonder one of the major benefits of LCHF reported among athletes (especially athletes seeking to extend their professional careers) is faster recovery and better joint health.

    Reply: #40
  38. Paul the rat
    @ murray,
    glucose does the damage at concentrations 7mM or higher.
    Yet another mechanism showing the toxicity of glucose. Most people would have 7mM or higher glucose after breakfast of cornflakes with banana chopped in.

    Here is the whole paper

    http://www.nature.com/cddis/journal/v5/n2/pdf/cddis201452a.pdf

  39. Tom Boyer
    Thank you, that little discussion of IGF-1 is extremely helpful. So animal protein raises levels of a potentially dangerous hormone -- but carbohydrates raise it too!

    Where you end up is in a place that makes totally good sense -- eat appropriate but not excessive levels of protein, and then get the balance of calories mostly from fat. The sad thing is people will read the headlines and eat too little protein and make up the calories with sugar and processed cereal grains -- which certainly won't make them any healthier.

    Reply: #43
  40. Ted Hutchinson
    Ann Fernholm has interesting comment on her meeting with Valter Longo Why is periodic fasting good for your body and health? Posted by Ann Fernholm den 31 March 2013.
  41. Zepp
    And did you know.. mothers milk altso rise IGF-1.. so you would grow and be a healty child!

    IGF-1 is nothing to be afraid of.. except abnormal levels!

    And when you alredy got cancer.. of any cause.. one dont want to get another factor that promote it!

  42. Joey
    My dad is 66 guess I'm going to buy him a nice skirt steak ;)
  43. Mark
    There's at least as much bread as meat in the picture shown. That's before considering the fries. (Curiously most fried potato products tend to be high GI, even though they also contain fat.)
    What is the effect of an entirely meat diet on IGF-1?
    Reply: #46
  44. Murray
    There are cultures in which a high proportion of meat is eaten. However, one has to examine them carefully before drawing conclusions. As Dr. Cate Shanahan observes, almost all traditional cultures eat slow-cooked meat on the bone and bone broth. They generally eat nose to tail and this balances glycine from bone and connective tissue with methionine from meat muscle. Also, in cultures like the Inuit and Cree in Canada they would eat the fatty meat and toss the lean meats to the dogs. So you cannot simply point to Inuit, for example, and say it is proven to be healthy to eat all steak.
  45. ivor cummins
    The study was a scientific sham and an engineering inference disgrace I did a quick analysis of their unpublished baseline datapack, and the study should never have passed the peer review process (never mind that the lead researcher had a whopping conflict of interest through being a founding member of a plant protein supplement company): have a look and see what you think.

    http://www.thefatemperor.com/slideshows/

    latest material link has upcoming cholesterol seminar draft slides - might be interesting to the clientele here also.....

    best regards

    Ivor Cummins
    http://www.thefatemperor.com

  46. Zoe
    Wow... really? I had no idea that smoking slashes triglycerides, raises HDL, decreases the number of "small, dense" LDL particles; lowers fasting plasma glucose, post-pardinal glucose, HB1Ac, fasting plasma insulin, and insulin resistance; -and- reverses Type II Diabetes. Screw the health authorities... Smoking sounds like a -great- thing to take up!

    On a more serious note, I think people do have a tendency to take in more protein than they really need. I always advise to calculate the amount you need, split it up into three equal portions for each of the meals, and then fill up on non-starchy, non-sugary vegetables plus generous amounts of fat until you're satiated.

    And regarding the IGF connection... The body has to maintain a delicate balance between anabolism (tissue buildup) and catabolism (tissue breakdown). In that sense IGF is not "good" or "bad." It's just a hormone the body uses to tell its cells to synthesize more proteins. I would rather eat a low carbohydrate diet with adequate protein and plenty of fat, to ward off pathological catabolism, but at the same time, avoid excess anabolism--that might ultimately lead to cancer. Carbohydrates are not only more potent at raising IGF levels, but as I'm sure everyone here already knows, they're even better at spiking insulin.

    Now, do you know what IGF stands for? Oh, that's right... "Insulin-like growth factor." Why? Because the protein structure of the two hormones is so similar, and each of them can mimic the other. (Injectable IGF has to be given with a meal, lest the patient suffer hypoglycemia.) Oops!

    P.S. I'm not Zoe Harcombe. Just another Zoe. :p

Leave a reply

Reply to comment #0 by

Older posts