Saturday, December 15, 2012

Complete Meals & GI (Non-)Sense, Glutamine & GLP-1, Low Thyroid & High Trigs, N-3 vs. N-6 Interactions, Optimal DHA Dosage in Kids W/ NAFLD, Selenium vs. Aluminum Toxicity

While this is not the exact combination of chicken breast, mashed potatoes and salad in the first one of today's news items, it's more than likely that the predicted GI (and thus probably what you would find if you looked it up in a table) overestimates the postprandial glucose response to this meal by ~50% and says absolutely nothing about the insulin response. It looks like complex meals and over-simplified theories, don't mix well, at all ;-)
78% that's the SuppVersity Figure of the Week and actually part of the additional information I provided on one of today's On Short Notice items. It's the increase in coronary heart disease risk women with subclinical hypothyroidism have compared to their peers with spot on TSH levels of 0.5-1.5mU/L (Asvold. 2012). In conjunction with other more or less recent studies, such as Mitchel's, Hsu's and Sahai's paper confirming the previously often talked about but not well-established 2-fold increase in congenital hypothyroidism from the early 1990s to the first years of the new millennium (Mitchel 2011), the predictive value of high TSH levels in the first trimester (early pregnancy hypothyroidism) for adverse pregnancy outcomes (Schneuer. 2012), the 30% risk increase in all-cause mortality in both women and men with subclinical hypothyroidism Tseng et al. reported in their paper earlier this year or the impairment of spatial working memory (Yin. 2012), Asvold's results only add to the evidence that the potential pitfalls of an increasingly prevalent metabolic dysfunction may have been ignored way too long.

  • More GI lovin' - On the menu today: Mashed potaoes with chicken, rapeseed oil or both (Hätönen. 2011) - I thought a mini-follow-up on Friday's post on the GI would be nice, 'cause some of you have not without reason been complaining that not everyone would eat pure white bread, like my students do.

    Figure 1: The real (=measured) GI of a meal does differ significantly from the theoretical prediction. So, even if the concept was worth bothering, the GIs of complete meals simply wrong, if they are not measured (Hötönen. 2011).
    Moreover, the mere fact that the scientists from the Department of Lifestyles and Participation at the National Institute for Health and Welfare in Helsinki, Finland, found that the addition of chicken breast, rapeseed oil and a salad, individually and in combination, had the GI of a meal containing six mashed potatoes (this was the parameter that was held constant) induced more than twofold changes in GI, with the addition of chicken breast having the greatest deviation from the predicted value in this group of 11 (initially 12) healthy subjects, three men and nine women, aged 36.2 (SD 14.1) years with a BMI of 21.3 (SD 1.7) kg/m² and normal glucose tolerance (see figure 1).

    Now given the fact that most data on the GI of complete meals has never been measured, but is actually based on the same predictions the scientists used, it stands to reason that...
    [...] this highlights the problems encountered when predicting the GI values of mixed meals. The protein com-ponent of the mixed meal evoked the largest insulinaemic responses and markedly increased the II of the mixed meal containing protein. However, introducing fat into the meal decreased the effect of protein on the insulinaemic responses (Hätönen. 2011)
    So, this does not simply bust the idea that you could calculate the GI, it does likewise show you that people who are still overtly scared of insulin (which is hillarious as long as you are insulin sensitive) are doing he exact wrong thing, when they make food-choices based on GI: Whey protein would in that case be in as much a no-go as simply eating a chicken breast with your mashed potatoes would be, because other than what most people believe, it does increase the insulin spike and thus reduce the glycemic index by allowing your body to clear the glucose more efficiently from the circulation.

    Suggested reads: The red box in the "Whey is More Insulinogenic than White Bread" post on the partitioning effects of BCAAs and yesterday's Facebook post on the anti-Alzheimer's effects of insulin.

  • Suggested read: Amino Acids for Super Humans the purported ergogenic effects of l-glutamine
    30g of oral glutamine have similar effects on GLP-1 as 75g of glucose (Greenfield. 2008) - Still a follow up on the GI discussion, I think you may be interested in. If you are someone who follows the questionable practice of ingesting large boluses of glutamine in the futile believe that this would increase your gains or speed up recovery, you may be pleased to hear that only 30g of oral l-glutamine produced an increase in the "Fat Burning Satiety Hormone GLP-1" (read more on GLP-1) that's on a gram to gram basis more pronounced than in response to insulin (0.41pmol/L per gram glucose vs. 0.75pmol/L per gram of glutamine; in 8 healthy subjects).

    Before you go and buy tons of glutamine, you should however consider that GIP, the pro-insulinogenic peptide and glucagon (ramps up gluconeogenesis in the liver) were likewise increased by the ingestion of this bolus of glutamine. It is therefore no wonder that glutamine has never been shown to be a "fat burner". Nonetheless, a 1999 study by Bowtell et al. would suggest that it may come handy to replenish liver and muscle glycogen after a workout (8g alone did increase glucose storage after a workout to a similar degree as a 18.5% glucose polymer solution and additional 25% glucose storage mostly in the liver, when both were coingested; cf. Bowtell. 1999). And if you don't care about that - your gut integrity could also be a reason to consider supplementation in the vicinity of particular strenuous or length workouts (see "Shedding Some Light on the Leaky Gut <> Exercise Connection") 

  • Practical relevance? Based on data from a 12-year longitudinal study, even women with subclinical hypothyroidism have 76% risk for coronary heart disease (p = 0.005), than women with spot on TSH levels of 0.5-1.5mU/L (Asvold. 2012). And even women well within in the "normal range" (TSH of 1.5-2.4mU/l) have a 41% higher risk of heart disease, although this is only borderline significant (p = 0.08). For men the TSH level alone had not predictive value. Spec. w/ regards to T3, there are also reports of increased incidence of ventricular disfuntion (Cassetti. 2009), increased cardiac death in CVD patients (Iervasi. 2003) and impaired recovery after a stroke (Alevizaki. 2007). We do yet have to be cautious, here as "low T3" syndrome could as well be the consequence of overall inflammation and the association does not tell us anything about what's the chicken and the egg.
    Low thyroid, high triglyceride (Hashimoto. 2012) -- If you are wondering why on earth your trigs won't come down, it may well be that it's the absence of sufficient amounts of thyroid hormone. I a soon-to-be-published paper in Endocrinology scientists from the Gunma University in Maebashi, Gunma, Japan, report that thyroid hormone regulates the expression of a Stearoyl-CoA desaturase-1 (SCD-1) which controls the production of trigs from carbohydrates.

    Surprisingly the 75% increase due to hypothyroidism and the 75% decrease in SCD-1 mRNA expression (both compared to a euthyroid state) the scientists observed in rodents in response to the administration of T3 were not mediated by receptor binding, but simply as a down-stream effect of direct modifications of the SCD-1 gene promoter between -124 and -92 bp by T3.

    On a related side note: It is actually the last mentioned mechanism which is the major new finding in the study at hand and not the fact that T3 can reduce the conversion of carbohydrates to triglicerides that is the actual news here. After all, the latter is something scientist should know, but obviously like to forget about ever since the late 1999s (Waters. 1997)

  • Omega-6 intake and not low omega-3 intake is the problem (Liou. 2007) -- Another older study, but one I am posting in response to a discussion some of you are having about omega-3 (ALA) intake in the post about safflower oil and DHT, because I simply feel that it's necessary to shed some light  on the erroneous assumption that by simply upping your intake of omega-3s or fish oil intake you could get away without decreasing your omega-6 intake, which in and out of itself will already increase the amount of anti-inflammatory omega-3 fatty acids (supplementation of DHA can still be advisable, specifically if you are a vegetarian).

    Figure 2: Effect of 4 weeks of high (red) vs. 4 weeks of low (green) linoleic acid (n-6) intake on short and long-chain omega-3 plasma phospholipid content in healthy men (Liou. 2007)
    In 2007, already Liu et al. conducted a very interesting experiment in the course of which they fed healthy men diets with identical amounts of omega-3 fatty acids (1% of the total energy intake), but two different amounts of linoleic acid (omega-6) and found that the high omega-6 intake (10.1% vs. 3.8% of the total energy intake) alone decreased the total amount of EPA among the plasma phospholipids (the major long-chain omega-3 fatty acid in fish oil), not just the ratio of omega-3 to omega-6, in the blood of their 29-45 year-old subjects by more than 25% (see figure 2). The paradoxical effect on DHA, on the other hand, would warrant further investigation, and underlines how reliant we are - if anything on the intake of pure DHA, which dropped in consequence to the test diet, which was devoid of fatty fish, while the original diet of the non-vegetarian subjects had fish in it.

    In this context, I would also like to point out that DHA is exactly where real fish is far superior to fish oil caps, because it has a way more favorable EPA:DHA ratio than fish oil caps. Salmon fillets for example have - depending on the fatty acid source in the diet 8.5g : 13.8g, 4.4g : 7.8g and 1.5g : 2.9g (all values per 100g) when the feed contains fish oil, fish and rapeseed and fish + rapeseed and rapeseed, only.

    And while the ratios are similar regardless of the chow, the data from the Seierstad et al. clearly shows that the fatty acid content of the diets can induce almost 5-fold differences in terms of the total DHA content and the omega-3 to omega 6 ratio (fish oil diet: 6.5, fish oil + rapeseed: 1.7, rapeseed: 0.6) of salmon fillets (Seierstad. 2003). 

  • It does not take much: 500mg DHA not more effective than 250mg  (Nobili. 2012) -- At least if it comes to its beneficial effects against liver steatosis in children  (mean age 11 years; BMI 26.6kg/m² and 24.4kg/m², in the low and high dose groups respectively with with NAFLD, the amount of DHA does not appear to be so important. According to the results of their 2-year registered controlled trial, both 250mg and 500mg of Docosahexaenoic acid lead to identical and profound reductions in the odds ratio of developing more severe steatosis during the study period.

    Figure 3: Odds ratio (comparing DHA supplement vs. placebo) of more severe vs. less severe liver steatosis determined every 6 months during the 24-month study period (Nobili. 2012)
    If you take a closer look at the data in figure 3, you will even have to concede that the lower dosage did a better job - while the mean odds ratios were only marginally lower in the 250mg DHA group, the extremely high standard deviations in the 500mg DHA would suggest that the 250mg dose appears to be more reliable. In this regard it may be interesting that the increase in serum DHA did mirror the dosages. With a 0.65% and 1.15% increase in DHA those were about 2x higher in the 20 boys and girls in the high dose group compared to the 20 kids in the control group who received a 290 mg linoleic acid germ oil supplement "placebo" (by the way, a monosaturated fatty acid placebo would have been more of a placebo than 290mg of omega-6)

    In view of the fact that the changes in triglycerides, ALT, HOMA-IR and BMI (which was not even different from the placebo group) were likewise identical, it does not appear as if anything that goes beyond the amount you will find in 2x cheap fish oil caps, or 10g even of the cheapest salmon fillet (see last paragraph of previous item) would be necessary to ellicit the anti-steatosis effect of fish oil - since those kids weight on average 55kg, an adult may want to add in another fish oil cap to get up to 360mg DHA per day or simply eat his fatty fish once or twice a week.

  • Selenium ameliorates aluminum toxicity (Viezeliene. 2012) -- With the whole upheaval about the potential negative side effects of the aluminum in vaccines, the formerly overlooked yet well-known neurotoxic (Exley. 1992; Gupta. 2005), hepatotoxic (Abubakar. 2003; Perez. 2005) and nephrotoxic metal (Geyikoglu. 2012) has all of a sudden returned to the center of public interest.

    Therefore I thought that you will be interested in the results of a study that's going to be published in the next issue of the Journal of Trace Elements in Medicine and Biology - irrespective of whether you believe, like Tomljenovic and Shaw that
    "the possibility that vaccine benefits may have been overrated and the risk of potential adverse effects underestimated, has not been rigorously evaluated in the medical and scientific community"(Tomljenovic. 2011)
    After all, vaccines are not the only potential source of aluminum in our environment, so that the ameliorative effects (all values remained normal in the aluminum exposed group, while there were 30%, 55% and 42% increases in GSH in the animals who received only the selenium injection) the co-administration of supplemental selenium had on the GSH reductions in liver, kidney and brain of Balb/c mice weighing 20–25g who were exposed (by i.p. injection)to AlCl3 (25 mg Al(3+)/kg body mass) for 16h could be important, regardless of whether you do or don't intend to get vaccinated.

    There is more about selenium at the SuppVersity, for example on its pro-fertility effects, and its anti-corrosive effects in the brain.
    That said, the dosage requirements necessary to maintain healthy GSH levels are probably much lower than the hillarious (for a healthy individual) in the study at hand 1,250µg/kg body weight of sodium selenite (Na2SeO3). Considering the elemental selenium content in Na2SeO3, the latter would equal to ~3,650µg - unquestionably WAY too much (remember this was a one-time dosage that was specifically co-administered w/ the aluminum). Even the 'no observed adverse effect' level for a 70kg man of intake which is ~1000µg/d (Whanger. 1999) appears unnecessarily high, so that the consumption of a handful of brazil nuts once or twice a week and/or other high selenium foods such as tuna, cod, oysters, shrimp, but also eggs, meats, poultry, mushroom and onions on a regular should suffice to get what you need, to fortify yourself against the constant assault of heavy metals.

    What would be interesting, though, is a study into the effects of adding selenium to the "safe" aluminum in vaccines. I mean, you cannot seriously tell me that we could not afford doing that and if it reduced any toxicity issues, why not?

That's about it for today, I did not post all too many new facebook news as of yet (I mean, come on, it's Saturday ;-), but if you are into medicinal horror-stories, you will certainly like the story about the flesh eating killer fungus. If you prefer microbes over fungi, you are probably better off with the latest insights into the associations of certain gutbacteria with the incidence of stroke. And if you are more into other aspects of the digestive tract you may be interested in the effects of gastric emptying time on postprandial gylcemia and insulin release.

If none of those news is to your liking, I suggest you either wait for me to post something else (could be happening within the next hours at, or simply enjoy the weekend and come back tomorrow when you are rested for another (hopefully) enlightening SuppVersity post.

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