Reply With QuoteI'm sorry but could this be a little clearer for everyone...? Is this saying milk makes your BMI look like nonsense? Didn't this already happen?
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Whole vs. Skim
Interesting research...
Short Communication
Dissociation of the glycaemic and insulinaemic responses to whole
and skimmed milk
Garrett Hoyt, Matthew S. Hickey and Loren Cordain*
Department of Health and Exercise Science, Fort Collins, CO 80523, USA
(Received 10 May 2004 – Revised 10 August 2004 – Accepted 14 September 2004)
In most carbohydrate-containing foods, the blood insulin response is predictable and is closely linked to the food’s glycaemic index (GI).
A single study, examining whole milk and fermented milk products made from whole milk, recently reported a large dissociation between
the GI and insulinaemic index (II) in healthy normal adults. Because the fat component of a food may influence the GI and II, it is unclear
if a similar dissociation may exist for skimmed milk in normal adults. We determined the GI and II of both skimmed and whole milk in
nine healthy, male (n 6) and female (n 3) subjects (23·6 (SD 1·4) years). No significant (P.0·05) differences existed between GI and II for
skimmed and whole milks. Significant (P,0·05) differences were observed between the actual and predicted areas under the insulin curves
for both skimmed milk (predicted 1405 (SD 289) pmol £ min/l; actual 6152 (SD 1177) pmol £ min/l) and whole milk (predicted 1564 (SD
339) pmol £ min/l; actual 5939 (SD 1095) pmol £ min/l). Consequently, a large and similar dissociation of the GI and II existed for both
whole milk (42 (SD 5) and 148 (SD 14)) and skimmed milk (37 (SD 9) and 140 (SD 13)). It is concluded that the dissociation of the GI and II
in milk is not related to its fat content.
MORE.... http://journals.cambridge.org/action...=02&aid=917916
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I'm sorry but could this be a little clearer for everyone...? Is this saying milk makes your BMI look like nonsense? Didn't this already happen?
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And is this really a study of nine (!) people? I would be inclined to ignore the results of such a study and be on the lookout for something with a larger sample size.
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Forgive me for my crappy comprehension, but I think the gist of this article is that both whole milk and skim have the same insulin response, despite the extra fat found in whole.
...I think?
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I second Alyion.
I have to wonder why their predicted response varied so much from the measured response, though.
✓ Member
Agreed. Even though Cordain is a legitimate researcher, I don't know that nine people really is significant. The primary interesting tidbit is that fat doesn't seem to have much of an effect on slowing insulin release, at least not in milk.Originally Posted by Ian Kovtunovich
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Concur. Statistically irrelevant regardless of potential veracity of findings.
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Wow. This kind of research report should really have a link to a glossary for the research area -- and maybe also a brief "explainer" as part of the abstract (everyday language summarizing the context and import of the research from the authors' perspective). Not sure how we can promote better -- i.e., more broadly communicative -- writing on the part of our scientists, but it's worth pursuing, in addtion to wide public access to the publications.
Rant aside, here's what I took away (I also skimmed the article): it seems to say that milk has been shown to produce more of an insulin response (a bad thing for those trying to ward off adult onset - i.e., Type II - diabetes) than would be predicted from it's Glycemic Index (GI). This particular study asked whether that has to do with fat content and found that no, in fact, the effect is the same with whole or skim milk. It's complicated. It doesn't mean you should stop drinking milk (the authors' site some recent research that shows milk having a counter-intuitive protective effect with respect to Type II diabetes in their concluding remarks in the article) but it does show that GI may not be enough - or robust enough an indicator -- to base all of your dietary choices upon.
Given that I don't have any experience with Type II Diabetes and that I really should be doing something else at the moment--- I'm not 100% convinced that I'm not getting some of these relationships and implications exactly wrong -- that is, understanding them in the opposite manner in which they are intended.
Would someone, who is more familiar with this area of research, please correct me, if that's the case?
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Due to the simple design of the study and the statistical methods required to test the data it is unlikely that a larger sample size would result in any difference in the outcome.
Outcome 1 - no difference in whole vs skim in glucose or insulin response. 9 people is usually sufficient to reveal differences in a simple paired sample t-test, and that feeling is solidified when I see the size of the p value (no indication for statistical trend that might reach significance with more statistical power)
Outcome 2 - both are significantly more insulinogenic than predicted from the glucose response. By definition, due to the identification of a significant difference, there were enough people in the study population.
A replicated study with more people may not observe outcome #2, if by more, we mean a population with significantly more variability. That might indicate a difficulty with generalizing the conclusions, but at minimum these results tell us that in a specific population (admittedly poorly defined in this brief communication) any type of milk (referring to the fat content at least, not the animal source) will produce a large insulin response with only a mild effect on blood glucose levels.
What is the practical significance? To me, very little. We (should) already know that glucose is only one of many stimulants of insulin production and release. Certain amino acids also do this job. Typically we are told that protein (and fat) will reduce the gycemic response, but that is assuming those macronutrients slow digestion and therefore the rate of glucose appearance in the blood. If the protein is easily and quickly digested, as in whey and presumably milk (an assumption based on the success of the milk diet supported in this forum and the results in this study), then you would expect the insulin response to be greater than is predicted from the glucose response. Furthermore, the glucose and insulin response are related in a complex, non-linear fashion. It is wrong to think that the higher the glucose the higher the insulin and that is the end of the story. Remember, the hyperinsulinemia will cause the glucose to decrease in response. Therefore, in a high leucine food like milk, you would expect the insulin response to be higher than predicted solely from the glucose content and, in turn, the glucose response to be slightly blunted.
These last few comments are nuances that are not practically relevant, however. Essentially, the take home message for this forum is that milk is a strong insulinogenic food. Insulin is needed for growth. Ergo...nothing more than we didnt already know.
Last edited by LimieJosh; 04-15-2010 at 05:03 AM.
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Apologies for the double post. However, I have just got around to reading the discussion and wanted to make an additional point.
The authors warn of the negative health implications of their findings due to the problems caused by hyperinsulinemia in type II diabetics. Long story short...hyperinsulinemia per se is not the problem. Outside of the context of insulin resistance, and the myriad of other metabolic problems it causes, there is little to no evidence that hyperinsulinemia should be a health concern.
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