Banner
    Meat And Cheese Scare: Protein May Be As Bad For You As Smoking
    By News Staff | March 4th 2014 09:46 PM | 10 comments | Print | E-mail | Track Comments

    There is good news for smokers; a cigarette is apparently no more harmful for us than a chicken wing.

    Or it's bad news for those Paleo diet people - they might as well be smoking cigarettes.

    Or if you have seen scare journalism and miracle vegetable claims based on population statistics for more than a few years, you just take the whole thing with a grain of salt (but not too much salt!) and keep doing what you are doing.

    A longevity analysis may not be drawing conclusions you like - if you eat meat in middle age you are 4X more likely to get cancer practically practically screams for a mainstream media headline - but that is because the methodology is rather weak. We can make correlations for almost anything in health, and that includes finding that eating meat is as likely to kill you as smoking is. Just find a population and a diet you don't like and see how many more people died than were on a diet you do like.  The authors suggest rates of cancer and death did not seem to be affected by controlling for carbohydrate or fat consumption, that animal protein is the main culprit. 


    Do you see anything scary in this picture? It isn't just your imagination, meat and cheese are bad for you. Until next year, when they are not. Credit and link: Pamela Graham Photography.

    It may be true that meat is bad. Smoking is obviously bad, but once the cultural vitriol snowballed people stopped asking the awkward questions about suspect claims. So we get stories about third-hand smoke killing us while the fact that only 10 percent of smokers get lung cancer and 50 percent of lung cancer patients never smoked gets ignored. Eating meat may be as bad as smoking because smoking is exaggerated. 

    It isn't just meat that is the problem in the new study; milk and cheese are also implicated. The only thing that gets the protein stamp of approval are beans. 

    The authors declare that those on higher-protein diets were 74 percent more likely to die (of any cause) than their more low-protein counterparts. They were also several times more likely to die of diabetes.


    Yet we need protein. So how much is too much? How much is enough?  That is the diet book of the week. And this look at population statistics gives some insight but won't settle any debates.

    Rather than look at adulthood as one phase of life, they break it into biological stages - and what works at one period may not work in another. In other words, what's good for you at one age may be damaging at another. Protein controls the growth hormone IGF-I, which helps our bodies grow but has been linked to cancer susceptibility. Levels of IGF-I drop off dramatically after age 65, leading to potential frailty and muscle loss. The study shows that while high protein intake during middle age is very harmful, it is protective for older adults: those over 65 who ate a moderate- or high-protein diet were less susceptible to disease.

    The latest paper draws from past research on IGF-I by corresponding author Valter Longo, Professor of Biogerontology at USC and director of the USC Longevity Institute, including on an Ecuadorian cohort that seemed to have little cancer or diabetes susceptibility because of a genetic mutation that lowered levels of IGF-I; the members of the cohort were all less than five-feet tall.

    "The research shows that a low-protein diet in middle age is useful for preventing cancer and overall mortality, through a process that involves regulating IGF-I and possibly insulin levels," said co-author Eileen Crimmins, the AARP Chair in Gerontology at USC. "However, we also propose that at older ages, it may be important to avoid a low-protein diet to allow the maintenance of healthy weight and protection from frailty."

    The researchers define a "high-protein" diet as deriving at least 20 percent of calories from protein, including both plant-based and animal-based protein. A "moderate" protein diet includes 10-19 percent of calories from protein, and a "low-protein" diet includes less than 10 percent protein.

    Even moderate amounts of protein had detrimental effects during middle age, the researchers found. Across all 6,318 adults over the age of 50 in the study, average protein intake was about 16 percent of total daily calories with about two-thirds from animal protein — corresponding to data about national protein consumption. The study sample was representative across ethnicity, education and health background.


    "The majority of Americans are eating about twice as much proteins as they should, and it seems that the best change would be to lower the daily intake of all proteins but especially animal-derived proteins," Longo said. "But don't get extreme in cutting out protein; you can go from protected to malnourished very quickly."

    People who ate a moderate amount of protein were still three times more likely to die of cancer than those who ate a low-protein diet in middle age, the study shows. Overall, even the small change of decreasing protein intake from moderate levels to low levels reduced likelihood of early death by 21 percent.


    Credit and link: 10.1016/j.cmet.2014.02.006

    For a randomly selected smaller portion of the sample – 2,253 people – levels of the growth hormone IGF-I were recorded directly. The results show that for every 10 ng/ml increase in IGF-I, those on a high-protein diet were 9 percent more likely to die from cancer than those on a low-protein diet, in line with past research associating IGF-I levels to cancer risk.

    The researchers also extended their findings about high-protein diets and mortality risk, looking at causality in mice and cellular models. In a study of tumor rates and progression among mice, the researchers show lower cancer incidence and 45 percent smaller average tumor size among mice on a low-protein diet than those on a high-protein diet by the end of the two-month experiment.

    "Almost everyone is going to have a cancer cell or pre-cancer cell in them at some point. The question is: Does it progress?" Longo said. "Turns out one of the major factors in determining if it does is is protein intake."


    Citation: Morgan E. Levine, Jorge A. Suarez, Sebastian Brandhorst, Priya Balasubramanian, Chia-Wei Cheng, Federica Madia, Luigi Fontana, Mario G. Mirisola, Jaime Guevara-Aguirre, Junxiang Wan, Giuseppe Passarino, Brian K. Kennedy, Min Wei, Pinchas Cohen, Eileen M. Crimmins, Valter D. Longo, 'Low Protein Intake Is Associated with a Major Reduction in IGF-1, Cancer, and Overall Mortality in the 65 and Younger but Not Older Population', Cell Metabolism, Volume 19, Issue 3, 407-417, 4 March 2014 10.1016/j.cmet.2014.02.006

    Comments

    Hank
    When the social authoritarians came for the cigarettes, I remained silent; I was not a smoker.

    When they came for the trans fats, I remained silent; I did not eat Fritos.

    When they came for HFCS, I did not speak out; I did not drink soda.

    But when they come for my chicken wings, IT'S ON....

    (with apologies to Martin Niemöller)
    Yeah, yeah, we all know the quote, and usually I agree with the sentiment.

    But, seriously, fuck smokers.

    Greg M.
    There's no way this will extend beyond palliative and geriatric care, if that. I mean, some crazy shit happens in America, but no politician or his science advisor is going to commit that kind of political suicide, Hank. Could you imagine? "2014: The nation will be phasing into a vegan diet with mandatory compliance. By 2018, we expect that everyone will derive all of their amino acids from corn and beans." LOL!
    Begin with this assumption: it's all a joke. Then you will see the humour in everything.
    Hank
    Someone on a political staff would do some simple fact-finding and a politician would ask in a committee, 'Weren't some of you the same researchers claiming  few years ago that a starvation diet led to longer life? You weaned your mice on it from birth. Are you advocating that we starve babies?'

    Game over. 

    However, in goofier local constituencies this has happened. A school in New York City instituted mandatory vegetarianism
    Greg M.
    I'm not going to try to rationalize the irrational. A vegetarian school? What. The. Fuck. Pretentious Yuppie Problems!

    On topic: We've got Laron syndrome and gigantism/acromegaly each at opposite ["extreme"] ends of the IGF-1 [GH] continuum, and every other phenotype in between. However, diet is just one of many factors influencing serum IGF-1/IGFBP-1 levels and, in the case of this study, the experimental mice that were implanted with 2x105 skin and breast cancer cells only belonged to high (18% total kcal) or low protein (4% total kcal in the melanoma experiment; 7% in the breast cancer one) intake groups. I'm splitting hairs, but I'm curious to see what a "moderate" murine experimental group would look like, just for the hell of it. Anyway, this was an interesting study.

     

    Begin with this assumption: it's all a joke. Then you will see the humour in everything.
    Vegetarianism isn't mandatory there. The cafeteria provides vegetarian lunches. Students may bring meat, but most of them don't. The population of the school is mostly Indian and other Asian, and they weren't eating the standard American cafeteria food that had been served. The kids love the food now.

    Hank
    You apparently do not understand the meaning of the word mandatory. When a taxpayer-funded, government-controlled body offers only one option, then it is mandatory. 

    The principal of the school said "the vegetarian menu fits right in with our mission" and then banned serving meat. That is a mandate. Where is the evidence being vegetarian is healthier? Nowhere outside Vegetarian Times. I am sure the 10 percent Hispanic and the white and meat-eating Asian parents love being told they are not being good parents if they eat a normal human diet. Instead of being a health issue, it is social authoritarian brainwashing, which seems to be the creepy undercurrent of this particular school's "mission".

    When people in California think a school district is bonkers, you know it is way over the line. 
    mbamphAP
    The point is good. After age 65 the wings don't give as good effects then because the bad for out weighs the good for health.
    mph_mba
    Greg M.
    No sir, the inverse is true:

    "Levels of IGF-I drop off dramatically after age 65, leading to potential frailty and muscle loss. The study shows that while high protein intake during middle age is very harmful, it is protective for older adults: those over 65 who ate a moderate- or high-protein diet were less susceptible to disease."
    Begin with this assumption: it's all a joke. Then you will see the humour in everything.
    John Hasenkam
    The underlying issue here may be methionine. I suspect it is that amino acid that is the principle agent involved here. I recalled a study indicating that in humans it is methionine that directly impacts on the mTOR pathways and played a role in driving IGFs. So I checked Wiki and the article there tends to confirm that recall. 
    The study design of this latest study doesn't impress me. If you look below you'll see studies going  back many years which identified methionine as the principle agent. So it is not necessary to reduce total meat intake but rather to reduce methionine intake. 

    What also needs to be considered is that health conscious people tend to eat more vegetables and reduce overall meat intake. Red meat, especially processed red meat, does appear to carry higher risks than other types of meat. This relates to the heme content, possibly the bad effects being mediated by iron loading, especially for colorectal cancer.

    There is scientific evidence that restricting methionine consumption can increase lifespans in some animals


    I've read a few studies on this. Eg. 

     Biogerontology. 2008 Jun;9(3):183-96. Epub 2008 Feb 19.Click here to read Links
        Forty percent and eighty percent methionine restriction decrease mitochondrial ROS generation and oxidative stress in rat liver.

        PMID: 18283555 [PubMed - indexed for MEDLINE

    Biochim Biophys Acta. 2008 Nov;1780(11):1337-47. Epub 2008 Jan 18.Click here to read

    Lowered methionine ingestion as responsible for the decrease in rodent mitochondrial oxidative stress in protein and dietary restriction possible implications for humans. In addition, the mean intake of proteins (and thus methionine) of Western human populations is much higher than needed. Therefore, decreasing such levels to the recommended ones has a great potential to lower tissue oxidative stress and to increase healthy life span in humans while avoiding the possible undesirable effects of DR diets.

    PMID: 18252204 [PubMed - indexed for MEDLINE]

    Biochim Biophys Acta. 2006 May-Jun;1757(5-6):496-508. Epub 2006 Feb 
    24. Links 
    Mitochondrial oxidative stress, aging and caloric restriction: the protein and methionine connection.Pamplona R, Barja G. Department of Basic Medical Sciences, University of Lleida, Lleida 25008, Spain. 

    Moreover, recent data show that methionine levels in tissue proteins negatively correlate with maximum longevity in mammals and birds. All these suggest that lowering of methionine levels is involved in the control of mitochondrial oxidative stress and vertebrate longevity by 
    at least two different mechanisms: decreasing the sensitivity of proteins to oxidative damage, and lowering of the rate of ROS generation at mitochondria. PMID: 16574059 [PubMed - in process]