Animal protein-rich diets could be as harmful to health as smoking | Science | The Guardian
I think this means there will be less libertarians around in 20 years time. (I have made the observation before that high protein diets are big with their side of politics: it appeals to their "strong man" fetish and insistence that progressive politics is for girls and limp wristed men. Did Ayn Rand's male characters eat half a cow for dinner before forcefully having their way with the strong willed heroine who just wants to be taken? I certainly expect so.)
It's an interesting study, though, as it says that high protein may be good for you once you get older. But before then, not so good at all for your longevity.
9 comments:
the report says the study doesn't correct for demographics.
"The apparently harmful effects of a high-protein diet might be down to one or more other substances in meat, or ***driven by lifestyle factors that are more common in regular red meat eaters versus vegetarians"***
Correlation is not causation.
Medical 'studies' that show correlation but have nothing conclusive to say about causation mechanisms are meaningless
Yes, I read of the limitations of the study in the report.
This is one of those cases where my strong hunch is that the correlation will be shown to involve causation, eventually. Like cannabis.
I like meat and protein quite a lot. But I think it a pretty safe assumption that as humans are omnivores, going overboard on any one food group (as Garry Taubes does in his diet) is not going to be a good idea.
Keep in mind that the reports says " no conclusions must be drawn" but that won't stop many people making conclusions ... . This is so typical of nutrition studies, further validation is overlooked and everyone discusses a paper that hasn't been properly studied.
The IGF linkage is interesting though because caloric restriction and the 5+2 diet do very much lower IGF levels and that is consistently associated with increased longevity. However I recall studies that suggest in humans it is the intake of specific amino acids that is critical because of the impact on the TOR pathways.
...
Longo divided them into three groups. The high-protein group got 20% or more of their calories from protein, the moderate group got 10 to 19% of their calories from protein, and the low group got less than 10% of calories from protein."
...
Terrible design. People who eat more vegetables are generally more health conscious, high protein diets could well equate with more fast food intake and processed meat intake.
Initial results should be treated with scepticism. I saw the same thing on the weekend. I was going through my archives and read one study which found remarkable benefits for lycopene in prostate cancer. That study was dated 2001. So I checked some recent studies and the excitement had become decidedly cooler because follow up studies simply did not bear out such promising results.
I thought the connection between cured meats and stomach and bowel cancer was very clear. I also thought the connection between overcooked meat and cancer was looking more and more likely too.
As people who are inclined to eat lots of animal protein generally are probably eating more bacon and char grilled steaks, I would have thought that could account at least partially for the survey results.
Yep, this came up today ...
http://www.sciencedaily.com/releases/2014/03/140306093708.htm
Look at related stories also.
You mentioned you were on the 5+2 diet. That is worth a shot Steve. I'm generally not a fan of diets but that one is based on some good science. My only problem with it is that during certain periods it may not be good to stay on that diet because of the loss of IGF may prevent recovery and perhaps inhibit the immune response. So when sick or with intense exercise , perhaps even times of high stress, possibly better to go off that diet until normal operations resume. Sorry for the ambiguities but it is very difficult for me to be very confident about these matters.
Be assured, John, "intense exercise" is rarely an issue for me!
Good because intense exercise is for exercise junkies and has bugger all to do with good health.
Steve,
I don't like this study. I think the real issue is about methionine.
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.
There is scientific evidence that restricting methionine consumption can increase lifespans in some animals
http://en.wikipedia.org/wiki/Methionine
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]
I see from that wiki article on methionine that eggs have lots of it.
So maybe it won't be the meat and fat that kill Garry Taubes, but the eggs!
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