Thursday, March 10, 2011

Wanna grow old? Set down the drumstick.



You bastards gave me a little caning this week for my analysis of a study regarding post-meal snacking. Some of you seemed to think that the "statistically insignificance" of the 10% difference in snack calorie consumption between people who ate quick meals and long meals made my argument moot. I've thought it over. There's a 10% chance you might be right. Therefore, I consider it statistically insignificant.

So you're wrong.

Just kidding. I'm impressed (and slightly terrified) by your intelligence, Nerd Herd. Thanks for keeping me on my toes!

And speaking of fitness and nutrition bloggers who occasionally make shit up, Dr. Gabe Mirkin completely stoked a lot of vegans this week by linking reduced protein consumption to longevity. The gist of it is that eating less protein causes a drop in a hormone called Insulin-Like Growth Factor-1 (IGF-1). This is a good thing because "IGF-1 shortens life by increasing cell DNA genetic damage, and causes cancer by blocking apoptosis that causes cancer cells to kill themselves before they destroy their host."

I tend to take Dr. Mirkin's writing with a grain of salt. On at least one occasion, I caught him making a super controversial claim with really dodgy back-up studies. I think it was regarding the icing of injuries to fight inflammation, which he claimed has worthless. When I tried to track down the study he sited (not a big link provider, that Gabe), it was nowhere to be found. I emailed him about it and he never responded. Of course, given my vast importance in the Fitness and Nutrition Blogosphere, I'm certain he saw my email, so I take the lack of response as an admission of guilt.

But I digress. This time, I think he's on to something, but he's a little twisty-turny about it. If you want the Short Attention Span Theater version:
  1. Here's a 2008 Science Daily article describing the study showing that decreased protein also decreases IGF-1.
  2. Here's a 2011 New York Times article about the study showing decreased IGF-1 can lead to a longer life.
  3. Eat about .8 grams of protein per kilo of body weight and you'll be able to sing "When I'm Sixty Four" and mean it.
Another thing Dr. Mirkin fails to mention is that the 2011 study, which is sort of the lynchpin of his commentary, involves an isolated community of Ecuadorian dwarfs. I don't think it's that important, but it's a rad fact that would liven up a somewhat dry post. Then again, he's a highly regarded and successful fitness and nutrition authority, so maybe he knowingly decided that the mention of South American little people would be statistically insignificant.

10 comments:

  1. Yup, for the past 6 months or so I've been liking the .8 grams of protein per kg of bodyweight -- about 36 grams of protein per day for me, which is easy-peasy with fruits and veggies alone. Okay, so still eat the occasional (once every one or two months?) salmon, and take my daily fish oil, but ta ta protein powders!

    Anyway, this recommendation of protein intake is right in line with findings of The China Study, not to mention the adult RDA of the good ol' U.S. Government.

    /michm

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  2. P.S. Not a fan of Mirkin's calorie-restriction model though. Bring on the calories for maximum nutrition!

    /michm

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  3. P.P.S. I think this is the study you're looking for: http://www.fasebj.org/content/early/2010/10/01/fj.10-171579.abstract

    Although, I suspect the part about ice is in the full text (not available without subscription).

    /michm

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  4. Still sounds pretty thin to me, Denis. You probably know, in numerous instances they have supposed established causality between some alteration in biochemistry and (insert your pet health peeve here) only to retrace later on because, frankly, doctors don't really know what the heck the human metabolism and biochemistry system really does and we are still a total black box.

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  5. Well shoot, Alex, I totally agree with you, but most nutritional science is thin. There's stuff I've taught for years that suddenly becomes invalid overnight because of one study. But if you look into this IGF-1 thing, science has been dancing with it for years, so it strikes me as wet Brawny paper towel thin as opposed to wet Kleenex thin.

    Also, I've been harping on about society's absurd need to over eat protein for years and have attacked it from a few other angles.

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  6. Apparently, I'm eating too much protein.
    And I thought I was doing so well!

    Sigh....

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  7. There's a good book that you can read online called The Protein Cycling diet. The gist is that it's known that fasting turns on autophagy but it seems that autophagy can be turned on in the absense of or low intake of protein so you don't have to fast to reap the benefits of autophagy.

    --Chris

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  8. Oh, great Fitness Nerd, have I offended you in some way? I'm feeling slightly ignored . . . sniff, sniff . . .

    j/k

    Hope you're staying safe and not out there trying to surf the tsunami waves.

    /michm

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  9. Not at all, MichM!!!

    I'd like to see that whole study. Kudos to you for tracking it down. It seems kind of odd that he could pull so much information from a facet of a study not even mentioned in the abstract.

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  10. I'll definitely send it your way if I'm able to get to it. Seems several people drew the ice conclusion (saw several articles mentioning it in relation to this study). The main point of the study being that the inflammatory response actually aids healing, so things like ice, NSAIDs, etc. inhibit the body's natural healing processes. I already knew that about the NSAIDs, but hadn't extrapolated it out to ice as well. Something I just might bring up to my PT at my next appt. -- he always has me finish a session with about 10 minutes of ice, which I loathe!!!

    /michm

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