Devil in the Feeding Trough: PGE-Response to "Bad" Red Meat from Grass-Fed Cattle Could Prevent not Cause Cancer, Stroke and a Whole Host of Autoimmune Diseases.

Image 1: You do not need to hunt your red meat like a paleolithic human being, just make sure it comes from grass-fed animals and you will have a "health food" that modulate the your prostaglandin response to inflammatory assaults and thusly reduce your risk of cancer, stroke and autoimmune disesases in a way no fat-free chicken breast will ever do.

I have had this in the news before, in the context of the purported health benefits of CLA, with respect to the modulation of the n3/n6 ratio in your diet and in various other context, you heard me saying, or, I should say, read me writing that rather than popping tons of fish oil caps, you should rather focus on decreasing your overall omega-6 intake by making healthy food choices at the supermarket. In this regard, choosing grass-fed over commercially raised beef (and other meat) products could turn out to be one of the most far-reaching choices you can make. While that alone will help you to concomitantly reduce the n-6 overload, as well as the overall PUFA-burden that is so characteristic of the "Western diet", a recent study shows that eating red meat, even instead of the "healthy" white fat-free chicken breasts, everyone is pounding these days, could actually have profoundly beneficial effects on your (auto-)immune health, protect you from cardivascular disease and (this is important for the ladies) get your menstrual periods and related issues back in order.

How grass-fed beef can help and why it outperforms bison, elk and chicken

In their study, the results of which were published in issue 31 of the journal Nutrition Research, K. Shane Broughton, Daniel C. Rule and Eldon Handrich did what scientists have been doing for decades now. They took mice (your usual carnivorous animal) and put them on one of those grain-based diets that was then enriched with "bad" red meat to make the animals sick. Well, ... while the design was in fact the same, the good news is that the intention was by way of exception not to show "prove" (as if mainstream dietary advice would be interested in "proof", anyway) how bad those nasty red meats are, but to evaluate whether the

[...] consumption of meat from range-fed bison vs range-fed and grain-finished cattle and grain-finished bison would lead to reductions in PGE-2 [prostaglandin E2] release without altering PGI-2 [prostacyclin] release after an infl ammatory stimulus in a mouse model.

Or put simply, the scienists wanted to check whether there was any truth to the superiority of bison compared to the "bad" red meat, when it comes to balancing out the ratio of PGE-2 and PGI-2.

Image 2: Bayer probably won't like it if everyone would start eating grass-fed beef. After all, that would probably reduce the sales of their COX-inhibitor Aspirin protect.

For those of you wondering about a) what those prostaglandins are and / or b) why you would want to modulate their ratio and not eradicate them completely, here is is brief rundown on one of my favorite topics, the Yin&Yang of life and, on a related note, the fallacy of common black-or-white thinking. As with almost everything there are also two sides (in fact there are many more ;-) to the inflammatory coin and PGE-2 and PGI-2, two acronyms that differ by only a single letter, are situated on those opposing sides. If they are expressed at the right ratio, everything is fine. The (relative) over-expression of PGE-2 that is commonly observed in people following the "Western diet", on the other hand, is associated with a host of pathologies, such as elevated risk for color ectal cancer, suppression of ovulation, and increased problems with rheumatoid arthritis and headaches. (Relative) underexperssion of PGI-2, the other hallmark result of the "food" people are poisoning themselves with on a daily basis, in turn, increases the risk of thrombosis and stroke. If any of that does ring a bell, but you do not know which one, you may want to check out the label of your Aspirin tablets - as a cyclooxygenase inhibitor Aspirin also blocks the production of PGE-2... but before you do now pop another of those tabs, I suggest you read on and learn that by paying a few extra bucks for "real meat", you will probably never have to take your daily dose of Aspirin protect.

And while the scientists were right, grass-fed bison is in fact better than grain-fed beef, a closer analysis of their results will show that the often-heard and widely believed statement that "bison is the best form of red meat you can possibly find" is nothing but another of the 1001 dietary fairy-tales of the bloggosphere.

Figure 1: Fatty acid content of the diet (in g per 100g of the whole chow) - saturated, mono- and polyunsaturated fatty acids (n3, n6), left; CLA content, right (data adapted from Broughton. 2011)

But let's first take a look at the experimental diets, the male CD-1 mice were fed for 14 days. What is interesting about these, is that, due to the inclusion of standard rodent chow, the differences in fatty acid composition between the grass-fed vs. corn-fed bison and beef diets and the diets that were based on (wild-type) elk and commercial chicken breast meat were actually not very pronounced (cf. figure 1). And while the inclusion of corn oil in every diet may sound blasphemic in the ears of the hard-core anti-grain croud (I know you are out there ;-), the addition of grass-fed meat to an otherwise standardized (and probably suboptimal) diet is actually a strength of the study. Thusly, the study does reflect pretty well, what could happen, if the average Joe or Jane did nothing else, but replace the corn-fed meat in his/her diet with meat from range-fed animals - and wouldn't you agree that this is a much more realistic scenario than living on nothing but grass-fed beef or bison?

Figure 2: Modulatory effect of 2 weeks on prostaglandin expression of mice after two weeks on diets enriched with range-fed, or feedlot fed meat of different sources (data adapted from adapted from Broughton. 2011)

And, if we focus solely on the PGE-2 to PGI-2 ratio (you can read up on its importance in the red box above), it is obvious that a small dietary change from grain- to grass-fed meets could actually have pretty profound effects on your (auto-)immune health. The data also shows that the "healthy" lean chicken breast your nutritionist has probably told you to eat actually should not be your first choice, when it comes to establishing a healthier prostaglandin milieu - and if you don't believe me, maybe you want to trust Broughton et al.'s judgement:

[...] chicken is promoted for its health benefits, yet in our study, it was no better for possible prevention of PGE 2-associated immune pathophysiology. Furthermore, chicken would not be as beneficial as grain-fed beef and elk consumption in reducing thrombos is and stroke potential.

So, while eating (commercially raised) chicken won't harm you, it will not help you steer your inflammatory response into either the PGE or the PGI direction. Broughton, Rule and Handrich are thusly right, when they conclude that

Based on results of the present study, consumption of any of the range-fed meat sources examined would be better at reducing the possibility of immune-related pathophysiologies than meat from grain-fed cattle. [...] Although range-fed beef and bison consumption would be equivalent for their immune-based role, consumption of range-fed beef would be better for the prevention of thrombosis and stroke.

Now, isn't that surprising? Chicken not the best thing you can eat? The "healthy alternative to beef" that has been pimped in the mass media lately only on par with plain beef and superior as far as reduction in the risk of stroke and thrombosis are concerned? Could it really be possible that the "bad red meat" is not so bad, after all? Is there the remote possibility that it's not red meat per se, but sick meat, or I should say the meat of animals we have been making sick by feeding them the same "healthy whole grains" with which we have been poisoning... ah, I mean nurturing *rofl* ourselves over all these years that is giving us migraines, arthritic joints, cancer, strokes and a whole host of nasty autoimmune diseases? I guess, I will leave it up to you to find and answer to that question ... and I am confident that you are smart to one and one, or rather grain-fed meat and (auto-)immune disease together ;-)

Pastured Anti-Obesity Advantage: Lower Body Fat, Reduced Liver Fat and Healthier Guts in French Rodent Study of Health Effects of Pasture vs. Regular High Fat Dairy Diet

Happy dairy, happy tummy. That's maybe not the sexiest, but potentially the most important result of this study.

Yes, it's only a rodent study. And no, rodents usually don't drink cow's milk, but the fact that  a pastured dairy diet leads to improved metabolic outcomes and to a stronger gut barrier compared with a standard dairy diet in rodents on an obesogenic high fat diet, is still - in my humble opinion - newsworthy!

As Bérengère Benoit and colleagues point out in their latest paper in the British Journal of Nutrition, "this may be due, at least in part, to the protective mechanisms induced by specific lipids" (Benoit. 2014).

Learn more about milk and dairy at the SuppVersity

Are Camels the Better Cows

UHT = Mutant Milk?

High Fat Milk Advantage

Milk, A Hormone Cocktail?

Milk Blocks Green Tea?

Dairy, A Full Review

Before we are dealing with implications and conclusions, though, let's briefly take a look at what exactly it was the French researchers did.

As Benoit et al. point out, dairy products derived from the milk of cows fed in pastures are characterized by higher amounts of conjugated linoleic acid (CLA) and α-linolenic acid (ALA, the major short-chain omega-3 fatty acid, not alpha-lipoic acid). As a SuppVersity Reader you will know that several studies have shown that these "good fats" have the ability to reduce cardiovascular risk and lower the risk of metabolic defects. Whether the latter can be said of plain dairy, when it is produced by pasture-fed cows and thus high(er) in CLA and ALA, however, remains largely unknown.

In the study at hand, a team of researchers from the Lyon University, INSA-Lyon, INRA, and the  INSA-Lyon did thus focus on the specific metabolic effects of pastured compared with standard dairy in a high-fat diet (HFD) context. In that, their focus was on the metabolic and intestinal health effects of the two different types of dairy.

Table 1: Composition of experimental diets (Benoit. 2014)

The experimental animals were fed for 12 weeks with a high fat + energy diet containing 20 % fat in the form of a pasture dairy cream (PDC) or a standard dairy cream (SDC). Samples of plasma, liver, white adipose tissue, duodenum, jejunum and colon were analysed. The

PDC mice, despite having a significantly higher food intake, exhibited lower fat mass, plasma and hepatic triglyceride concentrations, a lower level of inflammation in the adipose tissue than the mice on conventional dairy. Furthermore, the rodents with the pastured dairy in their diet exhibited a higher expression of hepatic PPARα mRNA and adipose tissue uncoupling protein 2 mRNA, suggesting an enhanced oxidative activity of the liver.

As you may remember from previous articles about CLA (specifically "CLA Destroys Body Fat & Increases Endurance! But at Which Costs" | read more), these results may be a direct consequence of the increased amounts of CLA in the pastured dairy diet (PCD) and its metabolic consequences on liver and body fat.

Gut health, again - can pastured dairy render your gut bulletproof?

Moreover, the PDC diet was found to increase the proportions of two strategic cell populations involved in the protective function of the intestinal epithelium, namely Paneth and goblet cells in the small intestine and colon, compared with the SDC diet.

Figure 1: Relative body composition and liver lipids (expr. in % of control; left) and fatty acid and sterol profiles of the regular and pastured dairy (Benoit. 2014)

That's particularly interesting in view of the ever-increasing rates / numbers of patients with (autoimmune) diseases of the gut and potential downstream systemic (ill) health effects of having a leaky gut (learn more). With the accumulating evidence of the far-reaching impact the health of our digestive tract has on the human metabolism, this finding may eventually even be more important than the increase in fatty acid oxidation (assuming it translates to humans, of course).

Do you want to learn the "Fat Truth Behind the Alleged Dairy Weight Loss Miracle"? Go ahead and go back to a previous article of mine to find out if it's calcium, protein, or healthy fats... or, if the whole thing is just another health hoax | read more

Bottom line: In spite of the fact that we still don't know if we'd see the same or even more pronounced health benefits with pastured vs. regular dairy in a human studies, my friend Alex Leaf who actually bet me on announcing the main results of the study at hand on Facebook weeks ago was right, when he states: "This is a study that supports that spending the extra bucks on pastured vs. regular dairy may be worth it."

Human subjects and a regular, not high fat (in rodents this is high fat + high carb = extremely high energy) diet are yet things I would like to see in a follow study, before I fully subscribe to the "pastured dairy hysteria". In the mean time, I would like to draw your attention to the deliberately underlined word "may" from the previous sentence ;-) | Comment on Facebook!

References:

• Benoit, Bérengère, et al. "Pasture< i> v. standard dairy cream in high-fat diet-fed mice: improved metabolic outcomes and stronger intestinal barrier." British Journal of Nutrition 112.04 (2014): 520-535.

The Dairy Double-Whammy: Fast & Slow Dairy Protein Equally Satiating, Pastured Cream Reduces Body Fat Accumulation & Strengthen Intestinal Barrier vs. Std. Cream

Whipped cream with strawberries - is it actually healthier with pastured cream? Is it less obesogenic, soothes inflammation and increases the oxidation while reducing the storage of body fat?

I guess I could have made two separate articles of the two recent studies from the University of Lyon (Benoit. 2014) and the INRA in Paris (Marsset-Baglieri. 2014), but in view of the fact that there are already plenty of dairy articles at the SuppVersity, I thought, I'd pack them into one large "Dairy Double-Whammy Appreciation Article"; and in that I am about to start with something the average SuppVersity reader should know already: "Milk protein fractions moderately extend the duration of satiety compared with carbohydrates independently of their digestive kinetics in overweight subjects."

Well, at least the first part shouldn't be news. The fact that this happens independent of their digestive kinetics, on the other hand, may come as a surprise.

You can learn more about dairy at the SuppVersity

Dairy Has Branched-Chain Fatty Acids!

Is There Sth. Like a Dairy Weight Loss Miracle?

Foods, Not Ma- cronutrients Build Healthy Guts

Lactulose For Your Gut & Overall Health

Is There a "Fat Advantage" for Dairy Lovers

Dairy, Diabetes, Estrogen, IGF-1, Cancer & More

Why? Well, "independent of their digestive kinetics", that means that the satiety effect does not depend on whether we're talking about fast- or slow-digesting dairy proteins. Or, practically speaking, it did not matter, if the subjects consumed

• 30g of casein (digested in 6h)
• 30g of whey protein (digested in 2.5h), or
• 30g of whey + casein protein (digested in 4h)

in conjunction with 30g of carbohydrates, the effect, i.e. the effects on  pancreatic and gastrointestinal hormones and the 17min increase in the time it took the subjects to ask for launch.

Figure 1: .Effects of the protein snackv. the control carbohydrate snack on the time period elapsing before the request for lunch in all subjects (n82) (a) and in early eaters (n=41) (b). The satiating effect of the protein snack is represented whatever the type of protein snack as well as in each protein group (Marsset-Baglieri. 2014).

In that, the effect on the size of a subsequent ad-libitum meal depended non-linearly on the proximity between the subjects' regular launch-time and the time the snack was ingested. With 32min (vs. only 17min), the satiating effect of  the liquid protein meal was thus significantly more pronounced in the "early eater" who could have consumed their regular lunch within less than 2h after the ingestion of the test "snack".

Dietary amino acid appearance in the plasma (Marsset-Bagliery. 2014)

Notice the significantly higher satiety effect of whey in the early eater group? I guess this is due to the fact that the peak amino acid levels after the casein meal are not achieved before the "early lunch eaters" would usually already have had their meal. So, if you intend to counter overeating at an all-you can eat buffet, you better have a whey protein 90 min before. A shake with casein protein, wouldn't be sufficiently suggested by the time you hit the buffet(see figure to the left). If you want to get the best of both "immediate" and long-term satiety, you better follow the longstanding SuppVersity advice to mix both.

Now that we know that dairy proteins can help you keep your weight in check, it's about time to have a look at the macronutrient, Marsset-Baglieri, et al. simply forgot in their previously discussed study: Dietary fats!

From dairy protein to dairy fat - this is where pasture may matter

The question whether pasture (grass-fed) dairy is healthier, better or what-not is a topic of ongoing discussion among the members of the health and fitness community. While some people believe that the slightly higher amounts of CLA and omega-3 fatty acids, doesn't make a difference, others pretend as if eating conventional dairy would cost you 10 years of your maximal life experience.

Figure 2: Effect of feeding a control (CT), a standard dairy cream (SDC) or a pasture dairy cream (PDC) diet for 12 weeks on the gene expression of different markers of inflammation in the epididymal adipose tissue: (a)IL-6, (b) Toll-like receptor 4 (TLR4), (c) cluster of differentiation 68 (CD68), (d)CD11c, (e) monocyte chemoattractant protein 1 (MCP-1) and (f) TNF-alpha normalised to hypo-xanthine-guanine phosphoribosyl-transferase (HPRT; Benoit. 2014).

If we take a look at results of a recent study from the University of Lyon (Benoit. 2014), you will realize: The truth lies - as usual - somewhere in-between.

The markers of inflammation, for example, were significantly reduced in rodents who were fed a 20% pasture (PDC) vs. 20% standard dairy cream diet (SDC; see Figure 2). The levels of PPAR-alpha & carnitine palmitoyltransferase in the liver and the levels of UCP2 in the adipose tissue, all three indicative of increased fatty acid oxidation in the liver and fat cells, respectively, increased (not shown in Figure 2).

And although the effects on the tight junctions of the gut (important for "leaky gut" prevention) were non-significant, the increase in the percentage of crypts with Paneth cells, the number of goblet cells per crypt and the expression of MUC-2 in the colon indicate that the pastured dairy had beneficial effects on the intestinal health of the rodents, as well.

Overall, the scientists attest that the replacement of a standard dairy cream with a pasture
dairy cream, albeit as part of a generally unhealthy "high-fat" (=hypercaloric) diet...

• lowers metabolic inflammation - for some markers even below the levels of the "healthy" standard (low fat) rodent diet
• prevents fat mass accumulation, despite increased energy intake - possibly due to an inxrease in lipid beta-oxidation, the pasture cream fed rodents could eat 0.8g/day more of the isocaloric chow and still presented lower body fat stores
• improves the protective function of the intestine - the increase in mucus coat thickness in the colon of the PDC mice might actually also have contributed to the reduced inflammation by decreasing the proportion of lipopolysaccharide crossing from the gut lumen to the systemic circulation

Their study is yet not without limitation, such as the lack of a detailed identification of the CLA isomers, which does not allow a causal analysis of the contribution of differences in the conjugated linoleic acid make-up to the reduction in body fat Benoi et al. observed. Similarly, the amount of beta-sitosterol and desmosterol, polyphenols and flavonoids which varied between the creams, could have figured in, sa well.

Suggested Read: "Dairy - The Good, the Bad or The Ugly? Latest Studies On Heart Disease, Diabetes, Cancer, Obesity and Co. Plus: What Dairy Peptides Do For Your Heart, Gut, Brain, etc." | read more

Bottom line: While we cannot fully explain why, the results Benoit et al present in their latest study clearly support the notion that pastured dairy could be wort the extra money. Whether it's a different CLA-composition, an increase in polyphenols and flavonoids or something totally different that makes the difference, will yet have to be elucidated in future trials.

What seems to be certain, though, is that the effects pastured dairy - in this case cream - would probably have been even more pronounced if it was combined with dairy proteins. And while this may not sound like news, the fact that Marsset-Baglieri, et al.'s finding suggest that the satiety effects of dairy proteins don't depend on the absorption kinetics of the protein, i.e. that whey is not necessarily less satiating than casein is big new, I personally would still like to see confirmed in a different scenario before I will be willing to fully buy into it.

Reference:

• Benoit B, Plaisancié P, Géloën A, Estienne M, Debard C, Meugnier E, Loizon E, Daira P, Bodennec J, Cousin O, Vidal H, Laugerette F, Michalski MC. Pasture v. standard dairy cream in high-fat diet-fed mice: improved metabolic outcomes and stronger intestinal barrier. Br J Nutr. 2014 Aug;112(4):520-35.
• Marsset-Baglieri A, Fromentin G, Airinei G, Pedersen C, Léonil J, Piedcoq J, Rémond D, Benamouzig R, Tomé D, Gaudichon C. Milk protein fractions moderately extend the duration of satiety compared with carbohydrates independently of their digestive kinetics in overweight subjects. Br J Nutr. 2014 Aug;112(4):557-64.

You Eat What You Feed: How Much Omega-3s Can You Possibly Pack into a Single Steak? The Impressive Effects of a "Grass(+)" Diet on Raw Meat & Meat Products

Learn more about the fatty acid and nutrient composition of grass-fed vs. regular beef this SuppVersity article is for you... and make the first step to reduce your CVD risk by 20% irrespective of whether or not you're going to eat grass-fed in the future!

I remember that I wrote a previous post about the detrimental effects of growing salmon on a high omega-6 diet. The result is a fish with an omega-3 to omega-6 ratio that is totally different from that of the wild-caught salmon everyone is raving about. Bad news, I know and to be honest, I am fed up with bad news.

Luckily you can rely on the scientists over at the Leibniz Institute for Farm Animal Biology in Germany: Dirk Dannenberger and his colleagues have just published a paper that sheds some light on the beneficial side of this ostensibly nasty link between the fatty acid make-up of the feed and the fatty acid composition of the meat of the animals we eat.

N6 in N3 out, N3 in N6 out - you see, it works both ways!

In their quest to find a way to change the fatty acid composition of beef products (German Corned beef (GCB), tea sausage spread (TSS), scalded sausage (SS)) the scientists simply replaced the regular maize silage + concentrate  and soybean meal based diet with a diet containing grass silage + concentrate with added rapeseed cake (12%) and linseed oil (3%) and *surprise* the amounts of short chain and long chain omega-3 fatty acids increases by 160%, 130% (EPA) and 70% (total long-chain PUFA = EPA, DHA, DPA).

Figure 1: Detailed comparison of the fatty acid content (mg/100  g) in Longissimus muscle of German Holstein bulls fed the regular corn + soy based (control) vs. grass + linseed based (experiment) diets  a different diet (Dannenberger. 2013)

Now that's cool, but in view of the fact that the major part of beef products is not bought as a raw steak of in form of ground beef, etc. what really counts is the net omega-3 gain in the previously mentioned beef products and that did not work as well as the enthusiastic

"n-3  PUFA  from  beef were  found  to  be  product-specifically  transferred  into  the  corresponding  beef  products"(Dannenberger. 2013)

 would suggest. After all, the increase in short chain and total long-chain omega-3s in the corned beef was only 40% and 50% and thus 75% and 29% lower than the increase in the "raw material".

So where did the good omega-3s go?

Well, I guess some of you will already have got it. German Corned Beef if freakin' lean. With only 2% fat the reason for the absence of omega-3s is thus simply that the fatty cuts don't even make it into the end product.

Figure 2: While the "grass-fed + enhanced" meat has identical amounts of iron, copper, zinc and selenium (not shown) it lacks the additional "vitamin E"-s that are in the corn-based chow; furthermore both forms are devoid of the fat burning isomer of CLA, this does yet also imply they don't entail the corresponding diabetes risk (Dannenberger. 2013)

So, despite the success of the study at hand, we would initially have to take up eating the whole animal, or rather all the cuts instead of throwing away the fatty ones just to be take the lean parts, fry them in plant oils and drown them in soy- or sunflower-oil based sauces to "water" the dry meat and spice up the blatant taste (with the decrease in total fat content in grass-fed cattle this effect will be even more pronounced, by the way).

Once we have made that important step from thinking that all animal fat must be bad, a simple change in the ingredient profile of our animals' feed could make a big difference to our health... what? No, you can already buy meat like that... you must be kiddin' me, right?  ;-)

---

This is not what you want: Farmed Atlantic salmon - raised with & fried in soy *yummy* (learn why)

Bottom line: I hope today's SuppVersity article did not just provide you with more information about the fatty acid profile of "grass fed, omega-3 pimped meat", but also made you smile. And if it did that I did already contribute to a 22% reduction your personal heart disease risk before you even ate one of the omega-3 steaks from the German cows.

How? Well, that's the CVD risk reducing effect of positive affect that was established in a large prospective study with 10 years of follow-up by Karina Davidson from the Department of Medicine, Center for Behavioral Cardiovascular Health at the Columbia University Medical Center in 2010 - I know I am so caring, but you don't have to thank me for that. I mean who would ready my stuff if it was not for you?

References:

• Dannenberger D, Nuernberg K, Herdmann A, Nuernberg G, Hagemann E, Kienast W. Dietary PUFA Intervention Affects Fatty Acid- and Micronutrient Profiles of Beef and Related Beef Products. Foods. 2013; 2(3):295-309.
• Davidson KW, Mostofsky E, Whang W. Don't worry, be happy: positive affect and reduced 10-year incident coronary heart disease: the Canadian Nova Scotia Health Survey. Eur Heart J. 2010 May;31(9):1065-70.

Short-Term Supplementation with Bovine Colostrum Does Not Improve Immune Variables in Well-Trained Athletes. Localized Effect on Intestinal Health Yet Possible.

Just in case you wonder that there were no news yesterday. Blogger was down, so it took me some time to be able to tell all of you, who followed my advice and tuned in to yesterday's episode of Carl Lenore's Super Human Radio: "Amino Acids for Super Humans" and heard Carl and me talk about his use of bovine colostrums as part of his peri-workout supplementation regimen that my concerns over the digestibility of the (mostly) immunomodulating long-chain peptides in colostrum (the milk mammals produce in the last days / first days after pregnancy), appear to be legit. At least the results of a recents study (Carol. 2011), which failed to produce any (systemic) immunomodulatory effects in well-trained athletes, would confirm my assumption that these longer amino acid chains are not able to overcome the tight gut junctions, which are genetically designed to "close" (the further tightening of the junctions is also known as "closure") within the first days after a mammal is born.

Figure 1: Two samples of human breast milk, which has a very different immunoglobulin composition than cows milk and colostrum, cf. Hurley. 2011 (image taken by Wikipedia user Azoreg)

That being said, the results of the aforementioned study that has been published in International Journal of Sports Nutrition and Exercise Metabolism do not come as a surprise for me: After 10 days of supplementation with either colostrums or skim milk powder, the 9 professional male athletes did show absolutely identical immune reactions to high intensity endurance exercise in a carbohydrate depleted state (the glycogen-depletion would augment the immunosuppressive effect of intense exercise beyond what would be seen under normal = glycogen-sufficient circumstances):

Plasma cortisol levels increased over time, reaching the highest level directly after exercise, and were still elevated ~22 hr after exercise compared with baseline values (p < .001). Neutrophil cell count was increased after exercise and dropped below starting values 22 hr after exercise (time effect p < .001). Circulating immunoglobulins did not change over time. A significant time effect was seen for interleukin (IL)-6, IL-10, IL-1-receptor agonist, and C-reactive protein, with levels being higher directly after exercise (p < .05). Other cytokines (interferon-γ, IL-1a, IL-8, tumor necrosis factor-a) did not show a time effect. No differences were seen between colostrum and skim-milk powder in any of the investigated variables.

The lack of systemic effects, i.e. effects on the body as a whole, due to the inability of the long chain peptides to cross the intestinal wall, on the other hand, does not preclude beneficial "side effects" within the gut, itself. Recent studies such as Moller et al. (Moller. 2011), for example showed direct beneficial effects of the "synergistic action of various milk bioactives" on dendritic cell (messengers between the innate and adaptive immunity) cytokine response within the gut. Further evidence for the localized effect of colostrum comes from a 2010 study by Marchbank (Marchbank. 2010) found that colostrum supplementation actually decreased or rather maintained gut permeability, which was otherwise reduced after exhaustive exercise:

Intestinal permeability in the placebo arm increased 2.5-fold following exercise (0.38 ± 0.012 baseline, to 0.92 ± 0.014, P < 0.01), whereas colostrum truncated rise by 80% (0.38 ± 0.012 baseline to 0.49 ± 0.017) following exercise.

These colostrum-specific results corroborate various studies on the effects of hydrolyzed milk peptides on insulin sensitivity, blood pressure and much more, indicate that there is much more to milk and milk products than the sum of their proteins, carbohydrates, fats, minerals and vitamins would suggest. Whether it always has to be colostrum, which is expensive and hard to come by, or raw, unpasteurized milk from the grass-fed cows of your local farmer would not suffice remains to be seen, though.

Grass-Fed Beef: Does CLA make the difference? Probably Not.

You certainly have heard of the benefits of the meat of grass-fed, i.e. naturally nourished, cows. Well, although I do not want to question its general superiority to corn-fed high omega-6 meat, it probably is not the CLA content which distinguishes good from not so good meat sources.

A recent study, which was conducted by scientists from the Iowa State University (Brown. 2011), scientists investigated the effect of a "balanced nutritionally complete diet" (31% energy from lipid, 13% from protein, and 54% from carbohydrate) with either high (1.17 g/d) or low (0.35 g/d) CLA content on various health parameters of 18 healthy women aged between 20 to 39 years over a 8 weeks period. These are the results:

The CLA diet did not result in any differences in insulin sensitivity, body composition, circulating blood lipids, or other measured disease risk factors as compared with the control diet.

Accordingly, the scientists concluded "that a diet naturally enriched with over a 3-fold increase in CLA from pasture-fed cattle "did not provide a health benefit when compared to "a similar diet composed of foods from grain-fed cattle."

While these results stand in line with the generally equivocal findings on possible health benefits from CLA supplementation in human beings, it remains questionable whether with a "nutritionally less complete [from a government standpoint]" diet, i.e. a diet with less carbohydrate content and a consequently higher meat consumption, the results would not have been totally different.

Figure 1: Fatty acid composition of grass-fed vs. conventional meats.

All that aside, a study by Irish scientists (McAfee. 2011) showed that the CLA content of grass-fed vs. conventional meat is not all that different, anyway. According to McAfee et al. it is rather the n-3 PUFA content of grass fed meat which "can significantly increase consumer plasma and platelet LC n-3 PUFA status" and may thus have a positive influence on metabolic risk factors in general and n-6 to n-3 PUFA ratio in particular.