Page 1 of 3 123 LastLast
Results 1 to 10 of 24

Thread: Studies assessing the effects of whole grain consumption within a good diet page

  1. #1
    JohnOrVladimir's Avatar
    JohnOrVladimir is offline Junior Member
    Join Date
    Apr 2013
    Location
    New York
    Posts
    3

    Studies assessing the effects of whole grain consumption within a good diet

    I'm curious if there are any studies done with human subjects assessing the effects of whole grains on otherwise healthy people.

    I would be very interested to see two groups of people who exercise, eat lots of natural foods with plenty of good meats and vegetables, the only difference being one eats whole grains and one doesn't at all.

    The reason I'm skeptical about the "all grains are garbage" idea is that the principal of us "not being evolved" to eat grains is rather specious seeming.

    You see, the pace of human evolution has sped up tremendously since the various Agricultural Revolutions we've had.

    Explosive population growth is driving human evolution to speed up around the world, according to a new study.

    The pace of change accelerated about 40,000 years ago and then picked up even more with the advent of agriculture about 10,000 years ago, the study says.

    And while humans are evolving quickly around the world, local cultural and environmental factors are shaping evolution differently on different continents.

    "We're evolving away from each other. We're getting more and more different," said Henry Harpending, an anthropologist at the University of Utah in Salt Lake City who co-authored the study.

    Recent acceleration of human adaptive evolution
    Human Evolution Speeding Up, Study Says
    Why human evolution accelerated | john hawks weblog


    So anyway, I would really like to see a direct study on the situation of people who, within a healthy lifestyle, eat whole grains, verses people who follow the primal model. Because the argument that our ancestors didn't do it has little persuasive power when we've evolved so far away from what they were.

    For instance, this study comes close to the mark:

    http://jama.jamanetwork.com/article....icleid=1199154
    http://www.nytimes.com/2012/07/01/op...-fat.html?_r=0

    "Although the very low-carbohydrate diet produced the greatest improvements in most metabolic syndrome components examined herein, we identified 2 potentially deleterious effects of this diet. Twenty-four hour urinary cortisol excretion, a hormonal measure of stress, was highest with the very low-carbohydrate diet. Consistent with this finding, Stimson et al31 reported increased whole-body regeneration of cortisol by 11β-HSD1 and reduced inactivation of cortisol by 5α- and 5β-reductases over 4 weeks on a very low- vs moderate-carbohydrate diet. Higher cortisol levels may promote adiposity, insulin resistance, and cardiovascular disease, as observed in epidemiological studies.32- 34 In a 6-year prospective, population-based study of older adults in Italy,35 individuals in the highest vs lowest tertile of 24-hour cortisol excretion, with or without preexisting cardiovascular disease, had a 5-fold increased risk of cardiovascular mortality. C-reactive protein also tended to be higher with the very low-carbohydrate diet in our study, consistent with the findings of Rankin and Turpyn.36 Other studies also have found reductions in measures of chronic inflammation, including CRP with a low–glycemic index diet."
    Last edited by JohnOrVladimir; 04-02-2013 at 10:38 AM.

  2. #2
    eKatherine's Avatar
    eKatherine is offline Senior Member
    Join Date
    Feb 2013
    Location
    Portland
    Posts
    4,873
    That would be interesting, but who would fund such a study? Currently studies are run comparing whole grain eaters with refined grain eaters, but the possible confounding factors involved in letting people choose their own diets are probably greater than the effect of the grains.

  3. #3
    JohnOrVladimir's Avatar
    JohnOrVladimir is offline Junior Member
    Join Date
    Apr 2013
    Location
    New York
    Posts
    3
    Quote Originally Posted by eKatherine View Post
    That would be interesting, but who would fund such a study? Currently studies are run comparing whole grain eaters with refined grain eaters, but the possible confounding factors involved in letting people choose their own diets are probably greater than the effect of the grains.
    There was this study, comparing 3 different diets of people being supervised by doctors attempting to lose weight:
    JAMA Network | JAMA | Effects of Dietary Composition on Energy Expenditure During Weight-Loss Maintenance

    It found that a primal-like "low-carb" diet, and a diet that emphasized whole grains and low glycemic load as well as veggies and meat, were both relatively good compared to the standard American high-carb diet.

    But I think probably the "low-carb" diet they used didn't emphasize fruits and veggies as much as the diet with whole grains, and therefore, it's not exactly comparable. Does anyone know of a similar type of study that more explicitly looks at low-grain diets rich in veggies?

  4. #4
    Paleobird's Avatar
    Paleobird Guest
    The OP is an interesting study but it proceeds from a faulty premise. It says more population=more genetic variation=faster evolution.

    But, the thing that the advent of agriculture also did, in addition to increasing the population horrendously, was to remove the pressure of natural selection from the picture. We now lived in settlements with a secure food source of grain and domestic animals and a fence to keep out the predators. Without the pressure of natural selection, genetic variation is rather random. Yes some things did turn out to be useful and were kept around by those who migrated north such as lighter skin and lactase persistence.

    The huge increase in the rates of celiac and other gluten intolerances I think pretty much shows that, no, we haven't evolved to eat grains. The fact that grains block the absorption of other nutrients also shows that, while some people manage to do just "fine" eating it, it is not really an optimal food for anyone.

    Primal101:http://www.marksdailyapple.com/why-g...0Daily%20Apple
    Last edited by Paleobird; 04-02-2013 at 01:04 PM. Reason: add link

  5. #5
    noodletoy's Avatar
    noodletoy is online now Senior Member
    Join Date
    May 2012
    Location
    land of the glass pinecones
    Posts
    2,329
    my n~1 of eating "healthy whole grains" was that i was "just fine". til i stopped eating them and realized that i'd been sick for decades. in almost 4 years being grain-free i haven't had a cold, cough, sniffle or sore throat.

    i don't care how it may or may not affect populations at large.
    As I ate the oysters with their strong taste of the sea and their faint metallic taste that the cold white wine washed away, leaving only the sea taste and the succulent texture, and as I drank their cold liquid from each shell and washed it down with the crisp taste of the wine, I lost the empty feeling and began to be happy and to make plans.

    Ernest Hemingway

  6. #6
    noodletoy's Avatar
    noodletoy is online now Senior Member
    Join Date
    May 2012
    Location
    land of the glass pinecones
    Posts
    2,329
    Quote Originally Posted by Paleobird View Post

    The huge increase in the rates of celiac and other gluten intolerances I think pretty much shows that, no, we haven't evolved to eat grains. The fact that grains block the absorption of other nutrients also shows that, while some people manage to do just "fine" eating it, it is not really an optimal food for anyone.
    i'll add other maladaptations, like cavities and over-crowded teeth.

    BBC News - Jawbones are 'shaped by diet', a study finds
    As I ate the oysters with their strong taste of the sea and their faint metallic taste that the cold white wine washed away, leaving only the sea taste and the succulent texture, and as I drank their cold liquid from each shell and washed it down with the crisp taste of the wine, I lost the empty feeling and began to be happy and to make plans.

    Ernest Hemingway

  7. #7
    JohnOrVladimir's Avatar
    JohnOrVladimir is offline Junior Member
    Join Date
    Apr 2013
    Location
    New York
    Posts
    3
    Quote Originally Posted by Paleobird View Post
    The OP is an interesting study but it proceeds from a faulty premise. It says more population=more genetic variation=faster evolution.

    But, the thing that the advent of agriculture also did, in addition to increasing the population horrendously, was to remove the pressure of natural selection from the picture. We now lived in settlements with a secure food source of grain and domestic animals and a fence to keep out the predators. ]
    Im sorry but the studies author is a paleoanthropologist, what are your qualifications to dispute the findings of his study?
    The idea that natura selction stopped when humans developed larger socities is a misunderstanding. Our environment changed drastically, and as a result, natural selection began selecting for a whole new suite of features. Or evolution really has sped up, and continues to speed up. The issue today is no longer how to fight off lions, but that doesnt mean we dont face selective pressures.

  8. #8
    Paleobird's Avatar
    Paleobird Guest
    Quote Originally Posted by JohnOrVladimir View Post
    Im sorry but the studies author is a paleoanthropologist, what are your qualifications to dispute the findings of his study?
    The idea that natura selction stopped when humans developed larger socities is a misunderstanding. Our environment changed drastically, and as a result, natural selection began selecting for a whole new suite of features. Or evolution really has sped up, and continues to speed up. The issue today is no longer how to fight off lions, but that doesnt mean we dont face selective pressures.
    Oh, I'm sorry, I was under the impression that you posted it in order to start a discussion. If it was just the ultimate word in unquestionable truth you should have said so.

  9. #9
    CasterlyGrok's Avatar
    CasterlyGrok is offline Junior Member
    Join Date
    Jun 2012
    Location
    Nebraska
    Posts
    4
    Quote Originally Posted by JohnOrVladimir View Post
    Im sorry but the studies author is a paleoanthropologist, what are your qualifications to dispute the findings of his study?
    The idea that natura selction stopped when humans developed larger socities is a misunderstanding. Our environment changed drastically, and as a result, natural selection began selecting for a whole new suite of features. Or evolution really has sped up, and continues to speed up. The issue today is no longer how to fight off lions, but that doesnt mean we dont face selective pressures.
    You should listen to Matthew Lalonde on Chris Kresser's podcast. What Science Really Says About the Paleo Diet – With Mat Lalonde

    He has a PhD in Biochemistry from Harvard which should satisfy your appeal to authority.

  10. #10
    eKatherine's Avatar
    eKatherine is offline Senior Member
    Join Date
    Feb 2013
    Location
    Portland
    Posts
    4,873
    PrimalCon New York
    I think there is a basic misunderstanding of what "natural selection" involves.

    "Natural selection" is when people with a certain trait tend to die younger and do not pass their traits onto future generations, while people with other traits disproportionately survive to pass on their traits.

    A clear illustration of the fact that natural selection is not really at play is that medical intervention keeps alive many people who would have died early in life, who can now pass on the genes that would have kept them from reproducing even a few generations ago. Think Type I diabetes, sufferers of which never had the opportunity to start families until quite recently.

Page 1 of 3 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •