5 ms·

We've known for a while the risk factor for heart disease is serum SFA levels, not necessarily SFA consumption. What has never been shown is that consuming SFA

We've known for a while the risk factor for heart disease is serum SFA levels, not necessarily SFA consumption. What has never been shown is that consuming SFA raises serum SFA; instead, it's been an understood truism held in place by policy and demagoguery. This study is small, but evidence convicting saturated fats was extremely weak to begin with, and we are now seeing positive evidence exonerating it. If you are interested in learning more about the history of nutrition, I highly recommend Nina Teicholz book The Big Fat Surprise. As others have mentioned, Phinney and Volek's books are a great overview off the science as of a few years ago. Phinney has been doing research on this for 40 years, quite an accomplishment, given how hard it has been to get funding for research that contradicts the policy line of "carbs are critical to survival and fat must be avoided".

deepsun 12y ago
Well, originally thought was valid. If we eat something, there must be more of it in body. Of course, now we see that body is more complicated in case of SFA, but generally assumption works for other cases. If a cat entered a house, you generally might expect that cat should be inside the house. The reality, as we see, is more complex than that, but generally assumption works, and worked for most of the cases. I just want to say that please don't blame scientists and policy makers. Everyone's smart after the fact.
- DanBC 12y ago
  > Well, originally thought was valid. If we eat something, there must be more of it in body. Sadly we replaced saturated fats (eg butter) with trans-fats (eg margerine). We know that trans-fats are terrible. That possibly caused some confusion. We knew people we still having heart attacks, we just thought that they were the group still eating saturated fats.
  - SoftwareMaven 12y ago
    And now we may have gotten worse: instead of trans fats (really bad!), we now get highly oxidized poly-unsaturated fats as restaurants have moved to seed oils for frying, which don't handle the temperatures nor the time in use very well. Oxidized fats do nasty things in the body, perhaps worse than trans fats. Bring back the stable saturated fats like coconut oil, palm oil (if sustainably produced), lard and tallow.
- mikeash 12y ago
  If you eat a cat, do you then contain a cat? No, you contain products of digesting a cat. The supposed cause/effect looks like magical thinking in hindsight.
  - deleted 12y ago
    [deleted]
  - jere 12y ago
    I think the original analogy refutes itself. If a strange cat enters your house, you remove it. Likewise, the human body has plenty of methods for regulating fats, sugars, sodium, etc. Of course, you can overwhelm those regulatory methods, but in general the assumption that there's a linear relationship between what you consume and the chronic levels seems pretty naive.
    - mtdewcmu 12y ago
      -- and if multiple strange cats enter your house, you start to think about closing the door. Interesting that you mention sodium. I've wondered whether the common advice to restrict sodium to reduce blood pressure actually has any effect. It would only work if your kidneys were not effectively regulating your blood sodium.
      - j_lev 12y ago
        http://www.marksdailyapple.com/salt-what-is-it-good-for/ http://www.marksdailyapple.com/salt-what-is-it-good-for/ According to this (there's a study linked within) salt's effect on blood pressure and other indicators of heart disease seem to follow a j-curve - too little or too much and you're at increased risk.
        mtdewcmu 12y ago
        The conclusions in there are clear as mud... :)
      - awa 12y ago
- refurb 12y ago
  Well, originally thought was valid. If we eat something, there must be more of it in body. Cholesterol is a great example. Your body makes the majority of cholesterol in your system. Diet only contributes a small amount.
  - SoftwareMaven 12y ago
    Unless you esat a lot, then your body makes relatively little. I love the way our bodies manage cholesterol, including dumping it into the intestines and recycling it if necessary. It's a beautiful example of how well our bodies regulate themselves when fed and tested well. My body has told me it needs 236mg/dL of total cholesterol right now. You couldn't pay me to mess with that.
- bluecalm 12y ago
  Well... with sugar for example we know for a long time that there is only about 50deciliters*80mg/DL=4grams of glucose in blood in average healthy adult. As people are eating tons of sugar a day (snickers bar has 27g, half a liter of cola has ~50g, half of it fructose but still) it's clear stuff doesn't just go into bloodstream as we would all die before finishing that snickers bar. Somehow though fat magically getting into blood and clogging arteries was something which was accepted as common sense. I do blame policy makers and scientists as healthy amount skepticism was clearly missing.
- SoftwareMaven 12y ago
  If it were just incomplete science, I'd have no problem with the path we've taken, but it wassn't just a case off incomplete science. It was a case of a handful of scientists deciding on a hypothesis, then fitting data to it. When others rightly complained, a campaign of personal attacks began. Those same scientists got themselves into important positions with organizations like the AHA, giving their arguments a strong appeal to authority, not to mention giving them a huge soap box. Even that probably would have self-corrected, except politicians got involved. In the late 70s, the McGovern commission decided everybody needed a low-fat diet, which eventually entrenched the dogma in all NIH-funded studies as well as government provided food programs like school lunches and food stamps. The really unfortunate thing is these scientists will likely be remembered for this misguided direction, rather than the huge steps they took in figuring out how to even approach nutritional studies in large populations. As Feynman said, you have to make sure you aren't fooling yourself, and you are the easiest person to fool. I would argue there was (and continues to be) a lot of self-fooling going on in the field of nutrition. Fortunately, it seems to be getting better, perhaps because of the influence of biochemistry and physiology.
- chrismcb 12y ago
  That is a poor analogy. The question isn't is the cat in the house, the question is will the cat be in the house tomorrow? How about next week?
- mtdewcmu 12y ago
  >> If we eat something, there must be more of it in body. That's not scientific thinking. That's more like pre-scientific Ptolemaic reasoning. If you drink more water, do you fill up with water?
commandar 12y ago
>What has never been shown is that consuming SFA raises serum SFA; instead, it's been an understood truism held in place by policy and demagoguery See also: cholesterol.
clumsysmurf 12y ago
Nina Teicholz's book "The Big Fat Surprise" has gotten good reviews, but so has Thomas Campbell's book "The China Study" ... they both seem well researched, but very at odds with each other.
- SoftwareMaven 12y ago
  Nina's is different. Campbell's was trying to prove what you should eat; Teicholz' followed the history of the science to see where it went. The difference is subtle, but significant. Based on what I've seen and read of Campbell, I think he would expect his work to be the last word on nutrition; I think Teicholz would see hers as a beginning. I recognize my own bias here, though. I think there are serious flaws in the China Study where Campbell reached beyond where the science illuminated. Teicholz isn't trying to prove a conjecture in the same way, so she isn't forced to do that (I think Robert Ludtig and David Perlmutter both did the same thing, so it's not just a function of vegetarian or not). Edit: I say read them both and decide for yourself. Don't accept either of their conclusions, but follow the science they reference and evaluate it for yourself.
  - hachiya 12y ago
    It's funny, but not surprising, to see the "I love science" crowd on HN so eagerly buy into the "all scientists have been wrong about heart disease" myths propagated by journalists like Gary Taubes and later by Nina Teicholz. Here are some reviews of Nina Teicholz's shoddy work. http://carbsanity.blogspot.com/2014/05/no-big-surprise.html http://carbsanity.blogspot.com/2014/05/no-big-surprise.html http://carbsanity.blogspot.com/2014/05/book-review-big-fat-surprise-by-nina.html http://carbsanity.blogspot.com/2014/05/book-review-big-fat-s... But Teicholz just follows in Gary Taubes' footsteps. See the numerous problems with that journalist's interpretation of health and dietary science beginning here: http://plantpositive.com/1-the-journalist-gary-taubes-1/ http://plantpositive.com/1-the-journalist-gary-taubes-1/

deepsun 12y ago

Well, originally thought was valid. If we eat something, there must be more of it in body. Of course, now we see that body is more complicated in case of SFA, but generally assumption works for other cases. If a cat entered a house, you generally might expect that cat should be inside the house. The reality, as we see, is more complex than that, but generally assumption works, and worked for most of the cases. I just want to say that please don't blame scientists and policy makers. Everyone's smart after the fact.

DanBC 12y ago
> Well, originally thought was valid. If we eat something, there must be more of it in body. Sadly we replaced saturated fats (eg butter) with trans-fats (eg margerine). We know that trans-fats are terrible. That possibly caused some confusion. We knew people we still having heart attacks, we just thought that they were the group still eating saturated fats.
- SoftwareMaven 12y ago
  And now we may have gotten worse: instead of trans fats (really bad!), we now get highly oxidized poly-unsaturated fats as restaurants have moved to seed oils for frying, which don't handle the temperatures nor the time in use very well. Oxidized fats do nasty things in the body, perhaps worse than trans fats. Bring back the stable saturated fats like coconut oil, palm oil (if sustainably produced), lard and tallow.
mikeash 12y ago
If you eat a cat, do you then contain a cat? No, you contain products of digesting a cat. The supposed cause/effect looks like magical thinking in hindsight.
- deleted 12y ago
  [deleted]
- jere 12y ago
  I think the original analogy refutes itself. If a strange cat enters your house, you remove it. Likewise, the human body has plenty of methods for regulating fats, sugars, sodium, etc. Of course, you can overwhelm those regulatory methods, but in general the assumption that there's a linear relationship between what you consume and the chronic levels seems pretty naive.
  - mtdewcmu 12y ago
    -- and if multiple strange cats enter your house, you start to think about closing the door. Interesting that you mention sodium. I've wondered whether the common advice to restrict sodium to reduce blood pressure actually has any effect. It would only work if your kidneys were not effectively regulating your blood sodium.
    - j_lev 12y ago
      http://www.marksdailyapple.com/salt-what-is-it-good-for/ http://www.marksdailyapple.com/salt-what-is-it-good-for/ According to this (there's a study linked within) salt's effect on blood pressure and other indicators of heart disease seem to follow a j-curve - too little or too much and you're at increased risk.
      - mtdewcmu 12y ago
        The conclusions in there are clear as mud... :)
    - awa 12y ago
refurb 12y ago
Well, originally thought was valid. If we eat something, there must be more of it in body. Cholesterol is a great example. Your body makes the majority of cholesterol in your system. Diet only contributes a small amount.
- SoftwareMaven 12y ago
  Unless you esat a lot, then your body makes relatively little. I love the way our bodies manage cholesterol, including dumping it into the intestines and recycling it if necessary. It's a beautiful example of how well our bodies regulate themselves when fed and tested well. My body has told me it needs 236mg/dL of total cholesterol right now. You couldn't pay me to mess with that.
bluecalm 12y ago
Well... with sugar for example we know for a long time that there is only about 50deciliters*80mg/DL=4grams of glucose in blood in average healthy adult. As people are eating tons of sugar a day (snickers bar has 27g, half a liter of cola has ~50g, half of it fructose but still) it's clear stuff doesn't just go into bloodstream as we would all die before finishing that snickers bar. Somehow though fat magically getting into blood and clogging arteries was something which was accepted as common sense. I do blame policy makers and scientists as healthy amount skepticism was clearly missing.
SoftwareMaven 12y ago
If it were just incomplete science, I'd have no problem with the path we've taken, but it wassn't just a case off incomplete science. It was a case of a handful of scientists deciding on a hypothesis, then fitting data to it. When others rightly complained, a campaign of personal attacks began. Those same scientists got themselves into important positions with organizations like the AHA, giving their arguments a strong appeal to authority, not to mention giving them a huge soap box. Even that probably would have self-corrected, except politicians got involved. In the late 70s, the McGovern commission decided everybody needed a low-fat diet, which eventually entrenched the dogma in all NIH-funded studies as well as government provided food programs like school lunches and food stamps. The really unfortunate thing is these scientists will likely be remembered for this misguided direction, rather than the huge steps they took in figuring out how to even approach nutritional studies in large populations. As Feynman said, you have to make sure you aren't fooling yourself, and you are the easiest person to fool. I would argue there was (and continues to be) a lot of self-fooling going on in the field of nutrition. Fortunately, it seems to be getting better, perhaps because of the influence of biochemistry and physiology.
chrismcb 12y ago
That is a poor analogy. The question isn't is the cat in the house, the question is will the cat be in the house tomorrow? How about next week?
mtdewcmu 12y ago
>> If we eat something, there must be more of it in body. That's not scientific thinking. That's more like pre-scientific Ptolemaic reasoning. If you drink more water, do you fill up with water?

commandar 12y ago

>What has never been shown is that consuming SFA raises serum SFA; instead, it's been an understood truism held in place by policy and demagoguery See also: cholesterol.

clumsysmurf 12y ago

Nina Teicholz's book "The Big Fat Surprise" has gotten good reviews, but so has Thomas Campbell's book "The China Study" ... they both seem well researched, but very at odds with each other.

SoftwareMaven 12y ago
Nina's is different. Campbell's was trying to prove what you should eat; Teicholz' followed the history of the science to see where it went. The difference is subtle, but significant. Based on what I've seen and read of Campbell, I think he would expect his work to be the last word on nutrition; I think Teicholz would see hers as a beginning. I recognize my own bias here, though. I think there are serious flaws in the China Study where Campbell reached beyond where the science illuminated. Teicholz isn't trying to prove a conjecture in the same way, so she isn't forced to do that (I think Robert Ludtig and David Perlmutter both did the same thing, so it's not just a function of vegetarian or not). Edit: I say read them both and decide for yourself. Don't accept either of their conclusions, but follow the science they reference and evaluate it for yourself.
- hachiya 12y ago
  It's funny, but not surprising, to see the "I love science" crowd on HN so eagerly buy into the "all scientists have been wrong about heart disease" myths propagated by journalists like Gary Taubes and later by Nina Teicholz. Here are some reviews of Nina Teicholz's shoddy work. http://carbsanity.blogspot.com/2014/05/no-big-surprise.html http://carbsanity.blogspot.com/2014/05/no-big-surprise.html http://carbsanity.blogspot.com/2014/05/book-review-big-fat-surprise-by-nina.html http://carbsanity.blogspot.com/2014/05/book-review-big-fat-s... But Teicholz just follows in Gary Taubes' footsteps. See the numerous problems with that journalist's interpretation of health and dietary science beginning here: http://plantpositive.com/1-the-journalist-gary-taubes-1/ http://plantpositive.com/1-the-journalist-gary-taubes-1/