Docosahexaenoic Acid (DHA) Blunts Negative Side Effects of Conjugated Linoleic Acid (CLA) W/out Hampering Its Effects on Body Fat Loss & the Expression of Obesity Genes

She already knew what scientists have recently discovered and now confirmed: You better stack CLA and DHA if you want lean and health offspring ;-)

Conjugated linoleic acid (CLA) is not only an omega-6 fatty acid, it's also a trans-fat (though a natural one) and still even scientists believe that it could contribute to the solution of the diabesity epidemic, if it (a) finally yielded the same extreme fat loss (yep, just the blubber, nothing else) results in human beings as in rodents (cf. "CLA Annihilates Body Fat and Increases Endurance") and (b) anywhere near appropriate doses would not hold he risk of inducing fatty liver disease and insulin resistance (Clément. 2002). At least with respect to (b) a "bodybuilding approach" to CLA supplementation which is based on the "if hammering your head against the wall hurts, you better make sure you wear a helmet" principle of stacking CLA and PUFAs, esp. the long-chain omega-3 fatty acid DHA, has already yielded some promising results in a study that has been published earlier this year (Fedor. 2013a).

Since, the deposition of fat in the liver in response to CLA supplementation is in the end only the logical consequence of CLA's lipolytic (=fat releasing) and anti-lipogenic (=inhibition of fat storage) effects in the adipose tissue, the absence of adequate data on the amount of fat in adipose tissue and muscle or the fatty acid composition of liver, adipose tissue, and muscle, nor did we monitor the changes in the expression of genes involved in fatty acid metabolism in adipose tissue and muscle in the respective study did not allow for the conclusion that the co-supplementation of DHA would not blunt the beneficial fat loss effects of CLA, as well.

Is it possible that high dose DHA blunts the negative and the positive effects of CLA?

In a paper that's going to be published in the next issue of Metabolic Syndrome And Related Disorders Dawn M. Fedor et al. describe the results of a follow up study, which dealt with this very question and I guess I am not giving away more than what you will already inferred from the headline of this post, when I tell you that the answer to the question in the subheading is "No, DHA does not blunt the beneficial effects of conjugated linoleic acid on adipose tissue!"

Figure 1: Relative body weight, liver weight, periuterine fat mass, muscle weigh, liver total lipid weight, adipose total lipid weight, and muscle total lipid content of the mice after 4 weeks on a 0.5% CLA, 0.5% CLA + 1.5% DHA or 1.5% DHA diets expressed relative to respective data from mice on the standard chow (Fedor. 2013b)

If you take a closer look at the data in figure 1 you will realize that the provision of a diet that contained 0.5% CLA (only the "active", but potentially hazardous t10, c12 isomer was used in the study) and 1.5% DHA did not blunt the beneficial effects on total and periuterine body fat mass in eight-week-old, pathogen-free female C57BL/6N mice. On the other hand, it did mitigate the negative effects on liver weight and (and this is actually quite remarkable) had identical beneficial effects on liver fat as the DHA only diet.

DHA + CLA = perfect synergists

Although the "equation" above may sound as if I had taken it right from one of those shiny adds in a muscle mags, it does in fact look, as if the combination of CLA + DHA was the silver bullet for healthy body fat (and I repeat only body fat not lean mass!) reductions in the absence of any dietary and/or exercise interventions.

Figure 2: Expression of selected genes involved in the synthesis, storage and release of fatty acids from the adipose tissue; the respective values (in a.u.) of the control group were all 100, so you can thing of these as percentages, as well (Fedor. 2013)

Moreover, the analyses of the expression of pro- and anti-obesity genes in the adipose tissue does actually support this claim:

"CLA significantly decreased the expression of LXRb, PGC1a, PPARg, SREBP1C, ACOX1, and CD36 adipose mRNA when compared to the control group. We also observed a trend for CLA to decrease the expression of HSL (P=0.08). DHA was not able to prevent any of these decreases in gene expression. CLA significantly increased UCP2 mRNA expression when compared to control group; DHA again had no effect." (Fedor. 2013b)

If we translate all these acronyms the scientists use to describe the data I've plotted for you in figure 2 into plain cause and effect relations, we could simply state: CLA induced changes in the expression of genes in the adipose tissue of the rodents that would prevent the maturation of adipocytes and the synthesis and accumulation of fatty acids, while increasing their release into circulation,  and DHA did not effect these changes.

DHA takes care of the energy that's released / not stored in fat cells

What the co-administration of DHA did, however, was to prevent the deposition of the energy that was released, respectively not even stored in the adipocytes in the liver -- and it did that so effectively that the overall weight of the liver of the mice in the CLA + DHA group was not greater than the the liver weight of the rodents in the control group.

Figure 3: Liver fatty acid composition (µmol/g) and omega-3 : omega-6 ratio after 4 weeks on regular (control), 0.5% CLA, 0.5% CLA + 1.5% DHA and 1.5% DHA diets (Fedor. 2013b)

In fact, the co-administration of conjugated linoleic acid and DHA did even reduce the total fatty acid content of the liver (not to a statistically significant degree, though) and brought about profound changes in its fatty acid content - most prominently, a whopping +975% increase in the omega-3 : omega-6 ratio (see small graph in figure 3) that were even slightly more pronounced in the CLA + DHA group than in the DHA only group (you do remember that CLA is an omega-6 trans-fat, right?).

Finally a stack that works -- but will it work in humans, as well? 

I don't know if it dawned on you, already, but dairy and butter from grass cows already has both CLA and DHA in it - what a lucky coincidence, isn't it? Still, there is one downside: You simply cannot eat enough of it to get anywhere close to the human equivalents of the amounts that are used in rodent studies.

Now, although both the changes in body fat levels in the CLA + DHA group were consistent with those observed in the CLA only group and the effects of the combination treatment on the changes in hepatic fatty acid composition were consistent with those observed in the DHA only group, there is still one question we have to answer: Are we going to see similar esults in humans?

To be honest, I still cannot answer this question, but if you take into consideration that no previous human trial used dosages in the 20-30g range simply because that would be unethical given the associated side effects, we may soon get an answer to this question - as soon as scientists dare to slowly escalate the dosage, trusting on the ability of supplemental DHA to blunt the negative, while conserving the beneficial effects of CLA.


References:

• Clément L, Poirier H, Niot I, Bocher V, Guerre-Millo M, Krief S, Staels B, Besnard P. Dietary trans-10,cis-12 conjugated linoleic acid induces hyperinsulinemia and fatty liver in the mouse. J Lipid Res. 2002 Sep;43(9):1400-9.
• Fedor DM, Adkins Y, Mackey BE, et al. Docosahexaenoic Acid prevents trans-10, cis-12-conjugated linoleic Acid-induced nonalcoholic Fatty liver disease in mice by altering expression of hepatic genes regulating fatty acid synthesis and oxidation.Metab Syndr Relat Disord. 2013a;10:175–180
• Fedor DM, Adkins Y, Newman JW, Mackey BE, Kelley DS. The Effect of Docosahexaenoic Acid on t10, c12-Conjugated Linoleic Acid-Induced Changes in Fatty Acid Composition of Mouse Liver, Adipose, and Muscle. Metab Syndr Relat Disord. 2013b Nov 21.

High Dose Omega-3 for Fat Loss? With 90% Lower Body Fat EPA Takes The Lead, DHA Second, ALA Distant Third... in Rats on Cornstarch or High Fat + High Sugar Diets

For Neo in the Matrix (courtesy of Warner Bros.) the choice was comparably easy. He had only two pills! You, however got to chose between ALA, EPA, DHA and, believe it or not, taking no pill at all!

I guess, those of you who are curious about the whereabouts of "your's truly" Adelfo Cerame Jr. will be disappointed to hear that he is currently so overwhelmed with clients and other duties that we have decided to turn the weekly contest prep series into a bi-weekly one.

Since this was more or less a last-minute decision, I just picked the next best study from my "interesting finds" folder and ... it turns out to be one of your, yet certainly not my favorite topics: Omega-3 fatty acids! That I am still skeptic about the usefulness, let alone necessity of respective supplements, does yet not change mean that I am deliberately ignoring interesting research on the unquestionable beneficial effects they have on lazy couch-potatoes and respective rodent models.

ALA, EPA, DHA - different acronyms, different effects?

Speaking of rodents, the soon-to-be published study by Hemant Poudyal, Sunil K. Panchal, Leigh C. Ward and Lindsay Brown from the Universities of Queensland and Southern Queensland in Australia unquestionably belongs into this latter category of "interesting rodent research on the benefits omega-3 fatty acids" (Pudyal. 2013). In order to differentiate the effects of alpha linoleic acid (ALA), the short(er)-chain brother to the long-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) people often falsely refer to as "fish oil" (while fish oil contains them, the average fish oil cap has ~40% EPA/DHA or 400mg in a 1g gel cap), the scientists assigned 96 male Wistar rats (9–10 weeks old) randomly to one out of 8 different diets containing

Carbohydrate, fat and protein content (rel. to total energy)

• corn starch,
• corn starch +1.1g/d ALA-rich chia oil,
• corn starch +0.7g/d EPA,
• corn starch +0.8g/d DHA, or
• high-carbohydrate, high-fat, 
• high carbohydrate, high-fat +0.7g/d ALA-rich chia oil 
• high-carbohydrate, high-fat +0.7g/d EPA oil and 
• high-carbohydrate, high-fat+0.6g/d DHA oil

The n-3 PUFA supplemented diets were prepared by adding 3% of the oil replacing an equivalent amount of water in the diet. n-3 PUFA supplemented diets were administered for 8 weeks starting 8 weeks after the initiation of the corn starch or high-carbohydrate, high-fat diet. The drinking water in all high-carbohydrate, high-fat fed groups was augmented with 25% fructose for the duration of the study.

Profound anti-obesity effects of EPA and DHA

Over the course of the 8-week supplementation period the researchers took daily measurements of body weight, food and water intakes. They performed two oral glucose (OGTT) and insulin tolerance tests (ITT) before and after the 16 weeks trial and measured the body composition by Dual-energy X-ray absorptiometric (DXA).

Figure 1: Body composition, lipid profile, glucose management (left to right) in rodents after 8 weeks on chia seed oil (ALA), EPA and DHA supplemented diets (date expressed relative to cornstarch non-supplemented control; calculated based on Poudyal. 2013)

If you take a look at my plot of the data, you may be surprised about the significance of the results. While it has to be said that even the "normal" control diet was not exactly what I would deem healthy (even for a rodent), it is nevertheless astonishing how pronounced the anti-obesity effects actually were.

Downstream benefits on organ health, ...

Figure 2: Contrary to what we have seen in previous studies (see TTA+fish oil), the high doses of the different omega-3s (HED ~20-30g!) had no effect negative effects on either the transaminase (ALT, AST), lactate dehydrogenase (LDH), alkaline phosphatease (ALP) or bilirubin values or the histology (histologies of hepatcytes not shown) of the liver of the rodents (data based on Poudyal. 2013)

Compared to the effects of the high doses of long-chain omega-3s the ALA treatment had a comparatively low impact on the adiposity. This could partly be a result of the fact that the omega-3 fatty acid metabolism in skeletal muscle and adipose tissue appears to be specific. While EPA and DHA
accumulated readily in these organs, when they were directly supplemented, the provision of ALA did not increase the contents of long-chain omega-3 fatty acids in either body fat or skeletal muscle tissue.

On the other hand, all omega-3 fatty acids showed beneficial effects on heart and liver the function of which had already been compromised by the 8 weeks on the extreme high carbohydrate or high sugar + high fat diet (reduced cardiac fibrosis, hepatic steatosis and inflammation in both the heart and the liver). In that, both, both, the improvements in body composition, as well as organ health, were more pronounced in the low-fat diet compared to the high-carbohydrate, high-fat diet.

... but negative effects on glucose management

Against that background it is actually surprising that none of the omega-3 fatty acids actually did what they are often hailed for: Neither ALA, nor EPA or DHA did improve the profoundly reduced glucose tolerance of the carb-o-holic rodents. On the contrary,...

"[...] EPA and DHA supplementation increased basal blood glucose concentrations, decreased intestinal glucose absorption and maintained the blood glucose concentrations for two hours after glucose loading with normal insulin sensitivity." (Poudyal. 2013)

Interestingly, this effect was probably brought about by yet another unexpected effect the high dose (human equivalent ~20-30g) omega-3 treatment had on the sympathetic nervous system:

"These effects were accompanied by increases in sympathetic activation seen as increased heart rate and cardiac output, increased force of left ventricular contraction and increased vascular responses to noradrenaline and sodium nitroprusside as observed with the hypothalamus–pituitary– adrenal axis response to stress and low blood glucose concentrations " (Poudyal. 2013; my emphasis)

As Poudyal et al. point out, this could also explain the profound weight loss effect in the cornstarch groups, and the "relatively smaller but significant changes in [high fat + high sugar] rats that still have an abundance of fructose and fat to meet the energy requirements."

From rodents to humans, from humans to...  fishmen?

The latest on the usefulness of omega-3 supplementation for active individuals and athletes: One of the most recent reviews of the issue states: "[O]nly a few studies have evaluated the impact of omega-3 PUFA supplementation on exercise performance. It has been suggested that the ingestion of DHA of approximately 1-2 g per day, at a ratio of EPA to DHA of 2:1, may be beneficial in counteracting exercise-induced inflammation and for the overall health of an athlete. However, the human data is inconclusive as to whether omega-3 PUFA supplementation, at this dosage, is effective in attenuating the inflammatory and immunomodulatory response to exercise, and improve exercise performance." (Micleborough. 2013; my emphasis)

These (at least for me novel) effects of very high doses of EPA and DHA on the sympathetic nervous system as well as the modulatory effects of the baseline diet are certainly things to keep in mind. This is particularly true in view of the latest epidemiological data which suggests that the consumption of comparatively minuscule amounts of fish oil has a population (and thus probably diet-)dependent effect on diabetes risk  (Wallin. 2013), with

• 17% increased risk of type-2 diabetes per 0.30 g per day increment in long-chain n-3 fatty acids in US residents, and
• -2% reduced risk of type-2 diabetes per 0.30 g per day increment in long-chain n-3 fatty acids in Europeans

The same goes for the U-shaped dose-response curve, Crochemore observed in one of the most recent controlled trials in the course of which a low dose (1.5 g/d) fish oil supplement improved the body composition and fatty acid metabolism of 41 women (60.64 ± 7.82 years) with high blood pressure and diabetes mellitus, while only 1g more, i.e. 2.5g/day, did not simply yield less pronounced decreases in body mass and waist circumference, the "high" dose fish oil supplement also reduced the already highly compromised insulin sensitivity of subjects even further (Crochemore. 2013).

EPA & DHA can come to the rescue, but a healthy diet would render supplements obsolete

If I did not know that fish oil was an invention of the 1990s, I would speculate that the "fishman" in the 1954 horror blockbuster The Creature from the Black Lagoon (Universal Pictures) was a "fish oil fat loss supplementation experiment gone wrong" ;-) Or joke aside - you don't seriously consider popping 70 fish oil caps a day to get the human equivalent of the ~1g of EPA or DHA the rodents in the study consumed, do you?

Regardless of the "optimal dosage", we should not lose sight of the influence and importance of the basal diet, when we evaluate the effects of DHA and EPA on body composition, lipid metabolism and not the least glucose management. It is, for example, very unlikely that we would see anywhere similarly pronounced effects in humans who are following a whole-foods based, "paleo-esque" diet without tons of cornstarch in it (control group), or plain sugar (and 17% additional fructose) that are on top of that hilariously protein-deficient (5%-6% is - if anything - enough not to die).

If you chose grass-fed over regular butter / dairy (makes sense only for high fat dairy), eat fish once or twice a week and replace the grain-based oils in your diet with coconut and olive oil, anything that goes beyond the occasional one or two fish oil caps will probably do more harm than good. And let's be honest, you don't really believe that you would get rid of the blubber that may still be covering your abs by copying the supplementation protocol of the study at hand and taking 70 fish oil caps every day to get your 20-30g of EPA and DHA, do you?

References:

• Crochemore IC, Souza AF, de Souza AC, Rosado EL. ω-3 polyunsaturated fatty acid supplementation does not influence body composition, insulin resistance, and lipemia in women with type 2 diabetes and obesity. Nutr Clin Pract. 2013 Aug;27(4):553-60.
• Mickleborough TD. Omega-3 Polyunsaturated Fatty Acids in Physical Performance Optimization. Int J Sport Nutr Exerc Metab. 2013 Sep 4.
• Poudyal H, Panchal SK, Ward LC, Brown L. Effects of ALA, EPA and DHA in high-carbohydrate, high-fat diet-induced metabolic syndrome in rats. J Nutr Biochem. 2013 Sep 28. pii: S0955-2863(12)00207-0. .
• Wallin A, Di Giuseppe D, Orsini N, Patel PS, Forouhi NG, Wolk A. Fish consumption, dietary long-chain n-3 fatty acids, and risk of type 2 diabetes: systematic review and meta-analysis of prospective studies. Diabetes Care. 2013 Apr;35(4):918-29.

Are Elevated Iron and Uric Acid Levels Too Much of a Price to Pay for a Creatine-Induced 11% Performance Increase?

Video 1 (GSSI): Notre Dame's Michael Floyd goes all out on the Wingate test (click to watch)

I guess you could say that these are the "classic days", here at the SuppVersity, contrary to my previous post on choline, which is - judged by the few people who still use it today, an "old school supplement" (cf. "Choline: Stronger, Faster, Leaner & More Muscular, or Just Another Dumb-and-Barbell Story?") - yesterday's post on caffeine highlighted the efficacy of a potent ergogenic aid and metabolic activator, with the effects of which most of us are so familiar that we are alway tempted to turn to useless crap like raspberry ketones, when what we are already doing is not only tried and proven, but based on respectable scientific data even more effective than the latest "innovation" from the snake oil industry. And let's be honest, haven't we all been tempted by one or another "new creatine", as well?

+11% peak performance in one week, solely from 5x4g of creatine per day!

A a matter of fact, creatine monhydrate does in fact share the same fate of being proven, but "boring" staple supplement and although that alone should be incentive enough to address the unquestionably outstanding +11% in anaerobic peak performance, +5% in continuous anaerobic performance and a +6% increase in total workload in a classic wingate anaerobic performance test speak, Barros et al. observed in a group of trained male subjects in response to a 7-day creatine loading protocol (20g creatine monohydrate, in 5 doses spread across the day, not glucose / sugar added; cf. Barros. 2013) After all, my gut tells me that the contemporary changes in the concentration of iron in the blood of the subjects in the the creatine arm of the study could revoke the mainstream-media fearmongerish hoopla over the purported dangers of the #1 natural ergogenic.

Figure 1: Basal iron, FRAP, malondialdehyde (MDA) and uric acid levels before and after 7-day supplementation with 5x4g of creatine monohydrate per day (based on Barros. 2013)

I mean, there is no debating, the level of iron in the blood of the creatine supplemented undergraduate students (age, 23.1 ± 5.8 years; height, 175.4 ± 2.3 cm; weight, 81.1 ± 9.3 kg) all of whom had been avid trainees for at least 6 months did increase by no less than 94.3%, while the subjects in the placebo group experienced a -21% reduction of these highly reactive molecules (Just as an aside, the decline in serum iron in the placebo group and the significant difference in baseline levels between the random groups, alone, render any implications at least questionable; I mean, wouldn't you expect the serum parameters to stay the same, when you do nothing extraordinary, aside from popping some sugar pills?).

Figure 2: Changes in wingate anaerobic performance (left) and exercise induced changes iron, FRAP, malondialdehyde (MDA) levels during the wingate test at the end of the supplementation period (based on Barros. 2013)

In conjunction with the likewise highly significant increase in uric acid levels, conventional (blogosphere-)wisdom, which constantly ignores the antioxidative nature of uric acid, which acts as efficient antioxidant and chelating agent for iron ions (Karlsson. 1997), limits the oxidation of polyunsaturated fatty acid in the erythrocyte membrane and prevents hemolysis (= the rupture of red blood cells) in vitro (Einsele. 1987), would suggest that taking creatine takes a close second to fructose on the list of the villains of the bad, bad "neolithic" century.

How dangerous is the creatine induced increase in iron?

Image 1 (Paramount Pictures): I guess, it must have been creatine monohydrate, then, that turned Robert Downey Jr. into Ironman ;-)

Now, despite the as of late publicly propagated concerns about increased iron levels and their potential causative role in the etiology of insulin resistance and diabesity (obesity + diabetes), recent scientific evidence suggests that "high iron", such as all previous scapegoats people like to hold liable, just to make sure not to admit that it is the sickening combination of laziness, convenience and unsound dietary advice that is at the heart of the current obesity epidemic.

Huang et al., for example, did observe a direct effect of iron overload on diabetes risk - the latter was however a result of hereditary hemochromatosis (a genetic defect in iron metabolism) in their 2011 rodent trial (Huang. 2011). Results from two more recent studies by Silva et al. also indicate that the metabolic disturbances lead to differential expressions of the proteins involved in the metabolism of iron and thus substantiate the associative (and not causative) nature of the relation between high iron / ferritin and the metabolic syndrome (Silva. 2011; Silva. 2013).

Iron not causative? So why does phlebotomy help, then? If you read my post on the recently published data from the first controlled human trial that investigated the effects of phlebotomy on markers of blood glucose management, you will be aware that the measures they took, e.g. the HOMA-IR, are not really appropriate to assess the effects of this particular treatment (cf. "Phlebotomy: Can You Bleed Yourself Healthy and Lean?"). Furthermore, it is only logical that the removal of some of this "highly inflammable stuff" from an inflamed body will provide health benefits, even if the latter was totally benign for someone who has a lot less inflammation going on.

What is even more important, though, is that the difference between exercise-induced increases in serum iron and diet and diabesity-related increases in the storage form of iron, ferritin, in the liver. This is particularly true in view of the fact that our understanding of the former, i.e. the exercise induced release of iron into the blood stream is more than limited (Roberts. 1989; Smith. 1994). What we do see in the Barros study, however, is that the overall effect of creatine is rather anti- than pro-oxidative, since the increase in overall antioxidative capacity (as indicated by the changes in the iron-specific FRAP essay; cf. figure 1) did not just...

• negate the potential negative effects of increased basal iron levels (see lowered baseline MDA levels post supplementation in figure 1), it also 
• countered the exercise-induced lipid oxidation during the 2nd wingate test (as indicated by lower MDA levels; cf. figure 2). 

Eventually, the scientists say, the increase in antioxidant activity that is brought about by the ingestion of 20g/day creatine irrespective of whether you exercise or not could actually yield "general health benefits" (Barrios. 2013); and I would like to add that evidence for Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, recovery from ischemia and, guess what, diabetes already exists (Tarnopolsky. 2000;"Creatine Ameliorates Type II Diabetes")! Certainly not bad for one of those bodybuilding supplements, "anabolics" or "gateway drugs", as creatine is often mislabeled , when a 100% clueless "journalist" tries to get the attention of his editor-in-chief, wouldn't you agree?

Suggested readings (some also mentioned in the text):

• The Pharmacology of Creatine (Part 1 and Part 2) 
• Supercharging Creatine With Baking Soda (click here to read)
• 5g/day Creatine for Type II Diabetics? (click here to read)
• All posts tagged with "creatine" (click here to read)
• Phlebotomy: Can You Bleed Yourself Healthy and Lean? (click here to read)

References:

1. Barros MP, Ganini D, Lorenço-Lima L, Soares CO, Pereira B, Bechara EJ, Silveira LR, Curi R, Souza-Junior TP. Effects of acute creatine supplementation on iron homeostasis and uric acid-based antioxidant capacity of plasma after wingate test. J Int Soc Sports Nutr. 2013 Jun 12;9(1):25. 
2. Huang J, Jones D, Luo B, Sanderson M, Soto J, Abel ED, Cooksey RC, McClain DA. Iron overload and diabetes risk: a shift from glucose to Fatty Acid oxidation and increased hepatic glucose production in a mouse model of hereditary hemochromatosis. Diabetes. 2011 Jan;60(1):80-7.
3. Orozco MN, Solomons NW, Schümann K, Friel JK. Response of urinary biomarkers of systemic oxidation to oral iron supplementation in healthy men. Food Nutr Bull. 2013 Mar;33(1):53-62. 
4. Roberts D, Smith DJ. Effects of high-intensity exercise on serum iron and α1-antitrypsin in trained and untrained men. Clin Sports Med 1989, 1:63–71.
5. Silva M, Bonomo Lde F, Oliveira Rde P, Geraldo de Lima W, Silva ME, Pedrosa ML. Effects of the interaction of diabetes and iron supplementation on hepatic and pancreatic tissues, oxidative stress markers, and liver peroxisome proliferator-activated receptor-α expression. J Clin Biochem Nutr. 2011 Sep;49(2):102-8.
6. Silva M, de Brito Magalhães CL, de Paula Oliveira R, Silva ME, Pedrosa ML. Differential expression of iron metabolism proteins in diabetic and diabetic iron-supplemented rat liver. J Biochem Mol Toxicol. 2013 Mar;26(3):123-9. 
7. Smith DJ, Roberts D. Effects of high volume and/or intense exercise on selected blood chemistry parameters. Clin Biochem 1994, 27:435–440.
8. Tarnopolsky MA. Potential benefits of creatine monohydrate supplementation in the elderly. Curr Opin Clin Nutr Metab Care. 2000 Nov;3(6):497-502.

A Double Dose of HIIT vs. Aerobics. Hazelnuts, Mushrooms, Strawberries = Polyphenol Laden Superfoods With Prebiotic, Anti-Cancer & Anti-Diabesity Effects. Plus: Backdoor to DHT

Actually the first post in today's installment of On Short Notice is a direct continuation of the SuppVersity Exercise Science Week with an intriguing novel contribution to the never-ending steady state vs. HIIT debate by scientists from the University of Birmingham (UK)

Hypothyroidism kills and therefore the SuppVersity Figure of the Week comes from a study on the effect of hypothyroidism on all-cause mortality from Denmark (Thvilum. 2013). The respective data comes from an observational cohort study and spans the years between January 1, 1978 and December 31, 2008. With an increased risk of  +52% (after stratification for the figure dropped to "only" +21%)  in the 3587 singletons, +61% in dizygotic twin pairs, but only +7% in monogyzotic twins, it's yet not quite clear, whether it's the being hypothyroid or rather having the disposition of developing respective problems is actually associated with an increased mortality. After all, you would expect similarly high levels in monogyzotic twins as in the rest of the population, if it was "only" about having a high TSH, which still is the only "official" accepted marker of clinical hypothyroidism.

Day 4 of the Exercise Science Week - A Double Dose of HIIT vs. Steady State Aerobics

(Cocks. 2013 & Shephard. 2013) -- If you ignored the titles and just read the first part of the methodological section it seems as if the two studies that were subsequently published in The Journal of Physiology late in 2013 were identical. What's identical, though is just the data set the two papers by scientists from the University of Birmingham are based on. The latter was acquired during a six-week experiment in the course of which 16 previously sedentary young men (BMI ~23kg/m²; age 21.5y) were randomized to a

• 

  34% increase in time to exhaustion, +91% increase in total work & exponentiated lean mass gains in response to HIIT + NAHCO3 (read more)

  classic steady state endurance training regimen - subjects cycled at workloads equivalent to ∼65% of their pre-established VO2peak for 40min in the first 2weeks, increasing to50min in the following 2 weeks, and 60min in the final 2 weeks; their obviously improved VO2peak was reassessed after 3weeks of training and workload adjusted accordingly

• sprint interval training  - subjects performed 30s "all out" (Wingate test) on a cycle ergometer using a load equivalent to 0.075kg per kg of body weight; each of the Wingate tests was followed by a period of 4.5 min of recoery (at 30W; <50rpm); the number of sprints increased from 4 to 6 sprints with one additional sprint every 2 weeks

As the scientists point out, all participants trained three (SIT) respectively five (ET) times a week for 6 weeks, and were excluded from the study if they were absent from more than two (SIT), respectively three (ET) sessions.

Figure 1: Overview of the relative changes of selected outcome variables measured in the "two" studies
(Cocks. 2013; Shephard. 2013)

While Cocks et al. analyzed the microvascular density and eNOS content of the muscles, the Shephard study, which was published a couple of weeks later, took a closer look at markers of intramuscular triglyceride breakdown and the expression of the anti-lipolytic lipid droplet-associated proteins perilipin 2 and 5. In previous studies, the researchers had observed that these proteins which are believed to protect the lipid droplets in adipose tissue from the "fat dissolving" lipase enzymes, appear to have a very different effect in the musculature, where PLIN2 and especially PLIN5 seem to act as key regulators of intra-muscular lipolysis and triglyceride breakdown (Shephard. 2013).

More similarities than differences?!

Figure 2: Selected parameters of body composition and blood glucose metabolism expressed relative to pre-exercise levels. (Shephard. 2013)

If we take a look at the outcomes of the studies (see figure 1, figure 2), it's not difficult to see that despite minor differences, most of the measured parameters in the Shephard study the observed differences, such as an increase of 7% in VO2Peak in the SIT vs. 15% in the ET group did not reach statistical significance. The same is true for the effect on the mitochondrial density, the insulin sensitivity, the maximal power WMax and the changes in body composition (see figure 2). Only the respiratory exchange ratio (RER), i.e. the ratio of carbohydrates to fats that were used during a 60-min endurance regimen at 65% of the VO2Peak, changed only in response to endurance training.

Despite this difference, the usage of intramuscular triglycerides (IMTGs) during exercise was increased after both trials:

"In comparison to pre-training, net IMTG break- down in type I fibres was significantly greater following training (training×time interaction; P<0.05), with no difference in net IMTG breakdown between groups. Both pre- and post-training, the reduction in IMTG content in type I fibres was attributed to decreases in IMTG density after SIT (pre-training, 21±13%; post-training, 38±7%) and ET (pre-training, 20±17%; post-training, 32±8%)." (Shephard. 2013)

The greater increase in IMTG response to exercise in the SIT (HIIT) group appears to be in line with the previously mentioned role of perilipin 5 (PLIN5) as a driving force of intracellular muscle triglyceride mobilization. After all, the PLIN5 expression of the interval training group increased to a significantly greater degree than the one of the endurance training group. A subsequent correlation analysis confirmed strong associations of PLIN2 und PLIN5 with IMTG breakdown and modest associations with muscular insulin sensitivity.

Para- vs. sympathetic overtraining: I would venture the guess that most of you will think of performance decrements, fatigue, depression, increased sleeping needs, constant weight or even fat gain, and lowered heart rate, i.e. the characteristic symptoms of parasympathetic (=addisonoid) overtraining, whenever they hear or read the term "overtraining". Its evil sympathetic twin, which is also known as basedowoid overtraining (named after morbus basedow) and likewise associated with performance decrements and fatigue yet in combination with an almost stimulant like restlessness, disturbed sleeping patterns, weight loss, and accelerated heart rate, is yet way less know. So, if you wake up in the middle of the night sweating like a pig and with a heart rate similar to the one you had during your last HIIT session, you better cut back on the weight lifting and HIIT side of your regimen - w/out necessary increasing the aerobics, though.

Bottom line: If you combine these mechanistic insights, with the main outcomes of the Cocks paper, which found ET and SIT "equally effective at decreasing arterial stiffness and increasing skeletal muscle capillarisation and eNOS content", even HIIT (or SIT, as it's called here) haters will be hard pressed to argue with Shephard et al.'s conclusion that..

"[d]espite the large differences in duration and energy expenditure between SIT and ET, we provide novel evidence indicating that SIT induces similar improvements [in almost all measured parameters and] provides a time-efficient exercise alternative to achieve improvements in aerobic fitness and insulin sensitivity." (Shephard. 2013)

So, now it's up to you 3x per week HIIT or 5x per week SIT? The answer appears to be clear, however, for people who are also strength training on a higher volume / density regimen, the addition of only 2-3 low(er) intensity aerobic sessions may still be the "safer" alternative in order not to overtax the sympathetic nervous system and keep a balance between sympathetic and parasympathetic activation in your routine.

More, really short news

Put introduction here

• Hazelnuts: A polyphenolic "superfood" that's prebiotic by nature (Montella. 2013) -- The skin of hazelnuts has only recently been identified as "one of the richest edible sources of polyphenolic compounds" - a polyphenol source that can compete with green tea and coffee, by the way (Clani. 2013).
  
  

  

  Hazelnut peel is laden with gut friendly prebiotics & antioxidant plyphenols

  In a paper that's soon going to be published in Food Chemistry researchers from the Italy and the United States report that the skin does also contain a whole host of potent pre-biotics:

  "Over thirty complex free oligosaccharides, composed mainly of galacturonic acid and N-acetylgalactosamine, were characterized for the first time in the present study. Their concentration ranged between 16 mg and 34 mg per g of extract." (Montella. 2013)

  And if you find that unfair, because you are allergic, you may be interested in a 2005 paper by Enrique et al. who found that their sublingual immunotherapy for hazelnut food allergy worked quite well in a first randomized, double-blind, placebo-controlled study with a standardized hazelnut extract (Enrique. 2005)

• 

  Inonotus obliquus (chaga mushroom) does actually looks like a tumor, but contains compounds that have the ability to kill prostate and breast cancer cells (photo by Tomas Čekanavičius)

  "Eat your mushrooms!" mothers are probably saying that not often enough (Kalogeropoulus. 2013; Ma. 2013) -- According to a recent study by Nick Kalogeropoulus et al. all five five wild edible mushrooms species (Lactarius deliciosus, Lactarius sanguifluus, Lactarius semisanguifluus, Russula delica, Suillus bellinii) from Lesvos Island, the researchers recently analyzed in their laboratory contained significant amounts of polyphenols, with the more abundant ones being p-OH-benzoic acid, p-OH-phenylacetic acid, o-coumaric acid, ferulic acid and chrysin. Moroever, the Greek scientists were also able to isolate the riterpenic acids oleanolic and ursolic acid (yeah, that stuff that's currently sold as test booster).
  
  If you add to that the not even published results of Ma, Chen, Dong and Lu, who fount that the ergosterol, ergosterol peroxide and trametenolic acid in Inonotus obliquus (chaga mushroom), another mushroom that has been used in TCM for centuries, do not only have potent anti-oxidant activity, but can also kill human prostate and breast cancer cells, the initially raised question, why your mother never told you to "eat your mushrooms" suddenly appears in a very different light, doesn't it?

• Did you know that the aggregate-accessory fruit (with the green dots on its flesh being its "nuts") has the highest total antioxidant capacity, when it's still green (see facebook news), can contain up to 160mg/g of fisetin (Kimira. 1998) and that the latter has been shown to reduce thyroid peroxidase activity (Divi. 1996) and thus to protect against thyroid cancer? Fisetin is also supposed to have anti-allergic and anti-angiogenic (pro - cardiovascular health) effects.
  Strawberry polyphenol fisetin ameliorates hepatic steatosis and lowers circulating glucose concentrations (Cho. 2013) -- While it's still a couple of days until the Strawberry season will begin it's still good to know in time that the fisetin content in strawberries can ameliorate hepatic steatosis and decrease blood glucose levels by increasing GLUT-4 (glucose transporter 4) expression in a rodent model of diet induced obesity.
  
  Unfortunately, the changes the Korean scientists observed in response to a human equivalent dose of 130mg/day was statistically significant yet not uniquely impressive and "thanks" to the increase in PPAR-gamma and the non-selective increase in GLUT-4 receptor expression (measured only on adipocytes), the rodents in the supplemented group got exactly as obese as their unsupplemented pears. Nevertheless, better "weighty" and healthy than skinny fat and sick, right? 

• Scientists find alternative androgen pathway - DHT synthesis from progestorone more effective than from testosterone (Kamrath. 2013) -- Usually it's my friend Carl Lanore who says that he, respectively Super Human Radio has the smartest listeners. I would hovewer argue that listening is easier than reading the stuff I produce (including sentences that are longer than the paragraphs of most other bloggers) and therefore it's no wonder that SuppVersity readers must be at least as smart ;-)
  
  

  

  The alternative pathway to androgen (DHT) synthesis as proposed by Kamrath et al.

  That being said, I just received a facebook message from Rob, who pointed me towards a very recent paper claiming that there was an "alternative androgen synthesis pathway" in human beings. "Alternative pathway?" Sounds like the adrenal gland and the DHEA => Testosterone => DHT pathway, right? That's what I thought, as well, but actually this one is different. As the pediatric scientists from the JLU Gießen (Germany) point out in their review of the literature, there is a hitherto largely overlooked "backdoor" by the means of which 17α-hydroxyprogesteron instead of it's 12,30 lyase product androstendione is 5α-reduced to 17α-hydroxy-dihydroprogesteron, which is then, in a 4-step process converted to 17α-hydroxyallopregnanolon (2α-HSD), Androsteron (12,20-Lyase), androstandiol (17b-HSD) and finally DHT (3α-HSD).

  "This so-called "backdoor" synthesis pathway appears to play an important role especially during the development of male fetuses, since respective defects will result in a suppressed virilization in boys." (Kamrath. 2013)

  Another context that's probably more important for most of you is the role of the "backdoor" in castrate (and probably also androgen suppression) resistant prostate cancer, where this alternative pathway jumps in, when the regulate substrate for DHT synthesis by a mere change in the specific 5α-reductase subtypes.

Now don't tell me you still haven't had enough for today? I mean, with the long article on the sprint vs. endurance study you've just gotten day 4 of the SuppVersity Exercise Science Week, and with the other short notice items, even those of you who have been missing nutrition and other news within the past couple of days should have gotten way more than your money's worth - after all, the SuppVersity is still free!

Since the same also goes for the facebook news, I'd suggest you head over to the SuppVersity Facebook Wall, where you will find roughly half a dozen of additional short news items every day. Examples? This is a selection of what you could already have known if you were already a friend, fan or whatever you call that on facebook, when you click on the "like button" at www.facebook.com/SuppVersity:

Just out: Part II of my interview with Sean Casey. This time about the A-Z of supplements for strength, endurance and all other trainees who want to boost their health and performance (read more)

• Skin protection from within - Orally ingested green tea or rather respective catechin metabolites end up in your skin and protects it from UV radiation (read more)
• Iron deficiency starts in the gut - Epidemiological findings confirm: Even people with mild gastrointestinal inflammatory bowel disease need more iron and co-factors in their diet to prevent deficiency than healthy individuals (read more)
• Hormonal contraception increases risk of HIV infection - Medroxyprogesterone acetate (MPA) suppresses both innate and adaptive arms of the immune system resulting in a reduction of host resistance to invading pathogens (read more)
• Grape seed and peel extracts stop working, when they are "purified" - Another case where man shalt not isolate what nature put together, if he wants to have the active ingredients survive the digestive process (read more)

And when you are done with those and i have not yet posted another handful of news, head over to Part II of my interview on CasePerfomance.com. Afterwards, you hit the power button switch off this damn machine and have a nice weekend with family and/or friends. 

References:

• Calani L, Dall'Asta M, Derlindati E, Scazzina F, Bruni R, Del Rio D. Colonic metabolism of polyphenols from coffee, green tea, and hazelnut skins. J Clin Gastroenterol. 2013 Oct;46 Suppl:S95-9.
• Cocks M, Shaw CS, Shepherd SO, Fisher J, Ranasinghe AM, Barker TA, Tipton KD, Wagenmakers AJ. High intensity interval and endurance training are equally effective in increasing muscle microvascular density and eNOS content in sedentary males. J Physiol. 2013 Sep 3.
• Divi RL, Doerge DR. Inhibition of thyroid peroxidase by dietary flavonoids. Chem Res Toxicol. 1996 Jan-Feb;9(1):16-23.
• Enrique E, Pineda F, Malek T, Bartra J, Basagaña M, Tella R, Castelló JV, Alonso R, de Mateo JA, Cerdá-Trias T, San Miguel-Moncín Mdel M, Monzón S, García M, Palacios R, Cisteró-Bahíma A. Sublingual immunotherapy for hazelnut food allergy: a randomized, double-blind, placebo-controlled study with a standardized hazelnut extract. J Allergy Clin Immunol. 2005 Nov;116(5):1073-9.
• Kalogeropoulos N, Yanni AE, Koutrotsios G, Aloupi M. Bioactive microconstituents and antioxidant properties of wild edible mushrooms from the island of Lesvos, Greece. Food Chem Toxicol. 2013 Jan 24. 
• Kamrath C, Hartmann MF, Wudy S. The alternative androgen synthesis pathway in humans. Klin Padiatr. 2013 Jan;225(1):3-7. [Article in German]
• Kimira M, Arai Y, Shimoi K, Watanabe S. Japanese Intake of flavonoids and isoflavonoids from foods Journal of Epidemiology. 1998; 8:168–175.
• Ma L, Chen H, Dong P, Lu X. Anti-inflammatory and anticancer activities of extracts and compounds from the mushroom Inonotus obliquus Food Chemistry. Feb 2013 [in press]
• Montella R, Coïsson JD, Travaglia F, Locatelli M, Bordiga M, Meyrand M, Barile D, Arlorio M.dentification and Characterization of Water and Alkali Soluble Oligosaccharides from Hazelnut Skin (Corylus avellana L.) Food Chemistry. Feb 2013 [in press]
• Shepherd SO, Cocks M, Tipton KD, Ranasinghe AM, Barker TA, Burniston JG, Wagenmakers AJ, Shaw CS. Sprint interval and traditional endurance training increase net intramuscular triglyceride breakdown and expression of perilipin 2 and 5. J Physiol. 2013 Dec 17.
• Thvilum M, Brandt F, Almind D, Christensen K, Hegedüs L, Brix TH. Excess Mortality in Patients Diagnosed With Hypothyroidism: A Nationwide Cohort Study of Singletons and Twins. J Clin Endocrinol Metab. 2013 Jan 30.

New Year, New Weight Loss Pills? Microencapsulated Conjugated Linoleic Acid (CLA) Works in Humans! So Well, In fact, That Subjects Lost Weight Too Fast, But...

Is microencapsulation like calling the artist him hammer away all the blubber? Hmm... maybe that's why it took Michelangelo > 3 years to complete his David. All jokes aside, is this encapsulation business really worth it or do you still have to sculpt your physique the good old way: Diet & Exercise?

If you look at the research, but even more the patents that were filed last year, you will realize the 2010s (looks awkward, right?) could become the decade of microencapsulation. Curcumin, green tea, vitamin C, scientists have and still are playing around with everything ME or NE... "ME or NE?" Yeah, right. Meanwhile it's actually so common that you often see only the acronym ME for microencapsulated and NE for nanoencapsulated in front of a supplement , extract or drug and know: They did it again.

In the case of conjugated linoleic acid (CLA), this is at least to my knowledge the first time that scientists used microencapsulation in order to make what appeared to become the big next thing in diet and weightloss pills - hold on, "next big thing" would imply that there had actually been "a big thing" and that's certainly not the case - at least nothing FDA compliant, let alone the Ally's and other junk from the pharmocracy.

New Year + New Technology + New Diet Pills = New, Leaner You?

Be that as it may, the study a group of Brazilian scientists has just published in Vascular Health and Risk Management does offer some hope, at least for those of the chronically overweight who are willing to use a weight loss supplement, exactly as the name implies, as a supplement that's taken on top of a calorically reduced and not just a "If I don't eat X,Y and Z - Quack A told me I can eat as much as I want and will still lose weight" diet. If you read the scientists research hypothesis, you will probably be surprised that they did actually expect that

"[...] microencapsulated CLA supplementation would improve glucose metabolism, the
serum lipid profile, and body composition, and decrease other cardiovascular risk factors associated with the metabolic syndrome." (Carvalho. 2013)

I mean, we all know that one of the problems with CLA - even in those mouse and few rodent trials, where it appeared to work - was actually that it lead to increases in liver fat, beginning fatty liver and consequent insulin resistance, right?

The addition of DHA to CLA  (as grass-fed butter has it) ameliorates the negative effects (read more). If you stick to the original  racemic mix of 9-cis trans-11 and trans-10, cis-12 isomers it may yet not even be necessary to protect your liver and insulin tolerance.

You will certainly remember the last study on the matter, where I speculated that the combination of DHA (not complete fish oil) and CLA a group of researchers led by Dawn M. Fedor had used to get only the beneficial, yet not the negative side effects in rodents, could actually hold the key to save and effective CLA supplementation in humans, as well (read more here). Now, with this study using a racemic, i.e. a 50:50 mixture of the naturally occuring CLA isomers 9-cis trans-11 and trans-10, cis-12 in humans and, as you are going to see in figure with nothing but beneficial effects on insulin sensitivity and glucose management, the question arises, whether you don't do best just eating more butter from grassfed cows.... ah, I am of course joking, I mean butter will clog your atheries, right? *rofl*

No, what I actually wanted to say was: If you look at the data in figure 2 & 3, there are 3 things I want you to keep in mind:

1. The sedentary, nonsmoking, nondiabetic, not post-menopausal, not having a previous hypocaloric diet, and not taking dietary supplements or any medication to reduce body weight (read up on "Long term dieting makes you fat and insulin resistant") were on a diet with a caloric deficit designed to have them lose 2kg per of body weight per month. That's pretty reasonable, but still a major difference to just popping a pill and waiting for the body fat to fall off (look at how successful the diet alone was!)

2. 

   Figure 1: Long diets need adjustments in caloric intake (Carvalho. 2013)

   The whole study lasted 3 months! And it was necessary to readjust the energy intake after 60 days to 1976.8 ± 67.31 kcal, in the CLA group, and 1745.5 ± 118.20 kcal, in the placebo group to keep the weight loss "stable" - check out figure 1 and you know why I put quotationmarks before the word "stable". Also take into consideration that the CLA group ate more mostly because they had already overshot as far as their 2kg per month weight loss goal was concerned.
3. The women would have had tremendously more success if they this study had had an exercise component, as well. With an energy expenditure of 22.27kcal/day and 23.35kcal/day from their usual "physical activity" - they could as well have been lying on the couch. Not that it was important or even smart to burn as many calories as possible, but ~23kcal is what most of you burn in 3-4 minutes of leisurely jogging or even brisk walking.

All that said: This is certainly not an optimal protocol and it cannot be said, whether the negative effects on glucose control would not have been evident if it was not for the game-changing caloric deficit (1). What has to be said in favor of the microencapsulated CLA (ME-CLA), though, is that it did not just come "side effect free", but had the exact opposite effect of what scientists still fear, namely the induction of insulin resistance.

Figure 2: Changes in parameters of blood glucose and lipid management (Carvalho. 2013)

That said, with a dosage for 3g of ME-CLA in *yummy* strawberry jam (sugar reduced *rofl*) per day, the absolute dosage was obviously lower than in most rodent studies and the usage of the racemic mixture could as well an important role in terms of the observed beneficial effects on blood glucose management. After all, previous studies have shown that cis-9,trans-11-octadecadienoate isomer is more potent than fish oil in improving lipid atherogenic risk markers (Valeille. 2004), does not share the pro-triglyceride and pro-insulin resistance effects of its brother and is probably also the anti-cancer isomer in CLA (Churruca. 2009). Unfortunately taken on it's own it does do little for weight or fat loss.

Figure 3: Effects of 3 months supplementation with 3g of microencapsulated CLA on body morphology (Carvalho. 2013)

Apropos, if you take a look at the data in figure 3 you will have to admit that the benefits were there, but compared to the health benefits, the weight loss benefits appear to be rather mediocre. And who telly me that the liver weight of the subjects did not still increase... well, it may not have been measured, but is overall very unlikely, 'cause that usually entails decreases and not improvements in blood glucose and lipid management.

Bottom line: Without a regular CLA control group this study tells us essentially nothing about the potency of microencapsulated conjugated linolic acid. After all, there are other human studies (also in obese individuals, also on a diet) reporting similar benefits with regular CLA (btw. in 99% of the cases also racemic mixtures). If anything the study confirms that in it's natural form, which is not an isolate of the fat burning and in high doses even fat annihilating (read more) trans-10, cis-12 CLA, is save probably healthy, but it is no magic anti-obesity pill (let alone something you take today and wake up ripped to the shreds tomorrow).

Another argument against the necessity of "functional" (?) CLA products, like ME-CLA jam, is the previous study showing that ~1.5g of CLA and vaccenic acid from dairy, beef, veal and lamp could prevent the subtle weight we all tend to ignore until it's already to late (read more)

Moreover, I suspect this will go for nano-encapsulated CLA (I bet a "market oriented" researcher has it already in development), as well, because encapsulation is something you want to do with stuff like curcumin, that won't even get where you want it, if you don't at least mess up your liver with some piperine so that it will let it pass unmetabolized. That's however not an issue with CLA, as the supplementation has proven time and again to increase CLA in serum and even tissue readily - even a higher intake of milk fat, which brings us back full circle to the image of the Kerrygold butter at the top, has been found to correlate significantly with higher levels of CLA in serum and adipose tissue (Jiang. 1999). So, if you see some strawberry jam with microencapsulated CLA in it on the shelves of your local supermarket in the course of 2013, you know that it's overpriced sugar... a pardon me, functional food with a reduced sugar content ;-)

On a different note: Thanks for all the good wishes and the appreciation you expressed in the comments. The did not go unnoticed! Hope all of you are more or less sober again, today, and in case you are not - don't forget the "Bismarck Herring" ;-)

References:

• Carvalho RF, Uehara SK, Rosa G. Microencapsulated conjugated linoleic acid associated with hypocaloric diet reduces body fat in sedentary women with metabolic syndrome. Vasc Health Risk Manag. 2013;8:661-7. doi: 10.2147/VHRM.S37385. Epub 2013 Dec 13.
• Churruca I, Fernández-Quintela A, Portillo MP. Conjugated linoleic acid isomers: differences in metabolism and biological effects. Biofactors. 2009 Jan-Feb;35(1):105-11.
• Valeille K, Gripois D, Blouquit MF, Souidi M, Riottot M, Bouthegourd JC, Sérougne C, Martin JC. Lipid atherogenic risk markers can be more favourably influenced by the cis-9,trans-11-octadecadienoate isomer than a conjugated linoleic acid mixture or fish oil in hamsters. Br J Nutr. 2004 Feb;91(2):191-9.