Farmed vs. Wild-Caught: Pollutants and A Low Omega-3/6 Ratio - Is Wild Caught Fish Always the Better Choice? Plus: Krill, Fish Oil, or Whole Fish - What's Best for Your Health?

Wild caught or farmed? If you google it, it appears to be as if eating farmed  fish could be worse than eating no fish at all, but is this actually true?

Farmed fish is the ugly duckling in the "superfood" family. It is - at least that's what you'll read on the Internet - low in omega-3s, full of "bad" omega-6 fatty acids and laden with all sorts of pesticides. But wild caught fish is expensive and if we all ate it day in and day out not exactly eco-friendly, right?

In today's SuppVersity special parts of which you may have recently seen pop up for a few hours in interview form over at www.fighterdiet.com, before Pauline Nordin and I decided that due to its length and complexity it was rather an article than an interview and should thus be published as such, I am going to tackle the issue of "farmed vs. wild-caught" and "fish vs. fish oil" from all possible angles.

Do not underestimate fish as a protein source - fish is more than just omega-3!

Salmon Better Than Whey?

Cod protein for recovery

Krill = Super Protein?

High EAA protein for fat loss

Fast vs. slow protein

5x More Than FDA Allows

I would like to start my elaborations with the results of a recent paper by Nichols et al. (2014). A paper, in which the scientists investigate whether the existing differences of the fatty acid profiles from farm-raised vs. wild-caught cold-water fish would depend on what the fish were fed.

The general consensus on the Internet appears to be that wild-caught salmon is in all ways superior to its "industrially produced" counterpart from the large fish farms. In that, the opponents of farmed fish consumption usually highlight the (I quote) "exorbitant" amount of allegedly unhealthy omega-6 fatty acids in farmed fish.

Now it is certainly undebatable that the ratio of omega-6 to omega-3 fatty acids in wild-caught vs. farmed salmon differs significantly. The previously mentioned study by researchers from the Commonwealth Scientific Industrial Research Organization does yet also show that this effect is not a result of "farming", per se. Rather than that, the increase in omega-6 and decrease in omega-3 fatty acids in today's industrially produced cold-water fish is a result of the ongoing reduction of the fish(oil) content in the fish food.

Figure 1: Fatty acid profile of farmed and wild-caught baramundi in 1998, 2002 and 2010 (left) and the corresponding omega-3 to omega-6 ratios (right) – it's worth noticing that "back in the day" of high fish oil diets, the farmed barramundi had a more favorable omega-3 to omega-6 ratio than their wild-caught relatives (Nichols. 2014)

In 2001, for example, when farmed barramundi (Lates calcifer | another cold-water fish that is raised in large aqua-farms these days) were still fed a high percentage of dietary fish oil, the farmed fish actually had a more favorable omega-3 to omega-6 ratio than its wild-caught counterpart (see Figure 1).

Over the past 13 years, the fish farmers have yet replaced large amounts of the increasingly expensive fish oil in the feed by cheap poultry oils. The consequences are obvious: While this practice may reduce the levels of dioxins and dioxin‐like PCBs (Berntssen. 2005), the substitution of fish oil with vegetable oil in the feed lead to decreases in the total amount of PUFAs, most specifically omega-3s, though. Thus, the originally highly favorable omega-3/omega-6 ratios of 5:1 for farmed salmon and 3:1 for farmed barramundi has declined to a meager 1:1 (Nichols. 2014).

High omega-6 in today's farmed cold-water fish - a problem? For the average physical culturist who is following a diet that is comparatively low in potentially pro-inflammatory omega-6 fatty acids (they are only bad for you, when they are consumed in excess), tehe deterioration of the omega-3 to omega-6 fatty acid ratio in modern farmed vs. wild caught fish is relatively unproblematic. Unlike it is the case for the average Westerner, who is in dare need of high omega-3 and low omega-6 foods to balance his or her excessive omega-6 intake from vegetable oils and industrially processed foods, farmed salmon is thus still a good source of protein and fats for those of us who are following a whole foods diet with a balanced fatty acid profile.

So, if the relatively high omega-3 content is not a problem, because the effects of "high omega-6" farmed fish on your omega-3 to omega-6 ratio is still neutral (that's the case if the ratio is approx. 1) there is no reason to avoid farmed fish, right?

From "high omega-6" to high levels of organic and inorganic pollutants

Unfortunately the high omega-6 content is not the only problem farmed fish is supposed to have.  Next to the previously discussed issue, the occurrence of various pollutants in farmed fish is another of the topics that will be mentioned in almost every online- or gym-debate on the consumption of farmed fish. Rumors have it that farmed salmon was loaded with toxic chemicals. And guess what!? To a certain extend that is absolutely true.

Figure 2: Fish is by far not the only POP source in our diets. Each 0.5 serving of the above foods is associated with the given increase in µg of urinary phthalate and phenol biomarkers in the urine of 6-8 year old girls and may thus increase their breast cancer risk later in life (Mervish. 2001)

When we are taking a closer look at the latest scientific evidence on the real world effects of thes persistent organic pollutants (POPs), it turns out that a high fish consumption has no measurable impact on the concentration of this potentially cancerous endocrine disruptors (they mess with your hormones) in our blood and adipose tissue. In fact, the latest study by Hausken et al. clearly indicates that the POPs in the blood of their fish fed subjects and the corresponding control group have different food products as their main sources (Hausken. 2014).

It is thus no wonder that the researchers from the University of Bergen did not find any change in serum or adipose tissue POP levels, when they had their subjects, 42 outpatients with different metabolic disorders, increase their intake of farmed salmon or salmon oil and compared their subjects' serum and fat pollutant levels to a non-fish eating control group.

The results were unambiguous: The consumption of farmed fish did not affect the steady-state of organic pollutants in either the blood or fat tissue of the subjects.

High levels of persistent organic pollutant (POPs) - a problem? The ever-increasing amount of POPs in our diet and other consumer goods (deodorants, perfumes and cosmetics are another source of POP) is a problem and a potential threat to our health, but farmed fish is not the item on your plate or cupboard that will tip the scale.

Due to the ever-increasing pollution of the oceans, rivers and lakes, POPs and other pollutants are no "farmed fish" phenomenon, anyway. If you look at the results of a recent study from the Hong Kong Baptist University, for example, you will have to concede that "eating wild caught only" is not going to protect you from being exposed to chemicals like BPA (Wei. 2011).

Figure 3: Polycyclic aromatic hydrocarbon (PAH) content of farmed and wild-caught salmon samples (Easton. 2002).

Moreover, the amount of organic pollutants in farmed fish could be easily reduced if the producers were willing to invest more money into quality fish food. The results of a 2002 study by Easton et al. clearly indicate for example that the increased polycyclic aromatic hydrocarbon (PAH) content of farmed vs. wild caught salmon could be easily reduced if these organic pollutants were not already present in hilariously high quantities in the feed the fish are fed. Buying uncontaminated fish food would thus give the farmers a degree of control fishers whose wild caught chinook salmon can contain up to 4.8x  more PAH than farmed salmon (see Figure 3) will never have.

Fish oil can be POP free, but not everything that glitters is gold

Fish oil is a highly processed substance. If the processing is done right, it is possible to remove large parts of the previously discussed POPs, as well as inorganic pollutants like mercury from the fishy sludge. The fact that it can be pollutant-free, however, does not necessarily mean that your fish oil caps will actually be free of any harmful substances.


The fact that fish oil producers may not do their job properly is yet not the only reason I am a strong proponent of consuming whole vs. "capped fish" and a whole foods vs. processed "supplement diet.  Why? Well, fish is by far not the only so-called "superfoods" for which we have seen time and again that the isolation of certain ingredients, of which we think that they are what makes these foods so "super", is not going to yield the results we are looking for.

In fact, recent studies which highlight the benefits of fish proteins for man and women who strive to build and maintain a muscular physique (learn more in a previous SuppVersity article) clearly suggest that the often-cited high selenium content of fish is not the only "good thing" you'd miss if you ditch your salmon, tuna and other fatty fish for cheap and convenient fish oil caps.

Warning! "Whole fish" does not include fried fish as you will find it on a "fish mac" or fish & chips and/or fish sandwiches. An increased consumption of these "fish" meals has been shown not to influence the cardiovascular mortality risk of 3910 adults aged 65+ years in a 2003 study by Mozaffarian et al. Moreover, the previously discussed amount of environmental pollutants in the fish is another determinant of its beneficial health effects.

In an editorial comment in the Journal of Internal Medicine Jacobs, Ruzzin & Lee highlight that "[t]he evidence that environmental pollutants can affect the health benefits of fish is supported by previous experimental studies" (Jacobs. 2014). In rodent studies, only decontaminated farmed salmon oil ameliorated the negative effects of high fat feeding. A POP-laden salmon oil from Atlantic salmon, on the other hand, accelerated the development of insulin resistance-related disorders in the lab animals (Ibrahim. 2011). The question, whether we should eat fish and take fish oil supplements is thus intricately related to the question whether we can obtain POP-free fish and fish oil products.

Table 1: The amount of organochlorides in various types of fish oil supplements bought on the Canadian market can be significant - similar results have been found on other markets | ^aΣ of 1,2,3,4 tetrachlorobenzene, 1,2,3,5 tetrachlorobenzene, and pentachlorobenzene; ^bΣ of α-HCH, β-HCH, and γ-HCH; ^cΣ of oxychlordane, trans-chlordane, trans-nonachlor, and cis-nonachlor; ^dΣ of p,p′-DDT and p,p′-DDE.(Rawn. 2009).

And even if you're not interested in being muscular, a recent study by Brazionis et al. clearly suggests that getting your 1g of long-chain omega-3 fatty acids from fish vs. fish oil supplements "may have additional cardiovascular benefits beyond the omega-3 effect". Effects which lead to a significant reduction in blood pressure the scientists observed only in those subjects who consumed fresh salmon (two 150 g servings per week of John West fresh Atlantic salmon), but not in their peers in the fish oil arm of the study (Brazionis. 2012).

Is fish oil the safer alternative? If you buy your fish oil from a manufacturer who can prove that each and every batch is tested for its POP and heavy metal content, it may be safer, but in view of the synergistic effects of protein, fat, certain peptides and a plethora of micronutrients you will be missing if you scrap your two weekly servings of fatty fish and turn to fish oil caps instead, this does not mean that it will be healthier.

When we are talking about toxic substances in fish and fish oils, we obviously cannot dismiss the heavily debated issue of heavy metal contaminations.

Heavy metals are clearly no farmed-fish exclusive!

While the heavy metal issue is still a matter of open scientific debate, the epidemiological evidence in favor of the profound health effects of regular fish consumption appears to suggest that it is less of an issue for the general population than the hysteric news on the Internet may make you believe.

Figure 4: Mean (bottom axis) and max (top axis!) mercury content (mg/kg) in fish (FDA Monitoring Program. 1990-2010 from a 2012)

For fitness junkies and bodybuilders who are trying to satisfy their alleged protein "requirements" of 3-4g of protein per kg body weight by shoveling down one can of tuna after the other, however, the heavy metal content of the cheap fish cans may become a problem.

Or maybe I should say: I personally would not use canned tuna as my primary protein source, when aiming for a protein intake of 3-4g per kg of body weight.

And this goes regardless of the fact that I believe that the risks associated with consuming tuna containing 0.10-0.75ppm methyl mercury (Yess. 1993) may be overblown in some of the sensationalist articles on the Internet and other mainstream media.

Similarly, I am reluctant to rely on the purported protective effect of the high amounts of cysteine and selenium in seafood. A protection, by the way, of which scientists have recently shown that is cannot mitigate the loss of cardioprotective effects of high omega-3 intakes in individuals with high hair mercury levels (Virtanen. 2009 | learn more).

So mercury is less on an issue than people claim? Probably yes. I would subscribe to the FDA recommendation to limit your fish intake to 2-3x fish meals a week. More specifically, you should forget about the idea of tuna as a "healthy snack" you can eat as often as you want to and stay away from more than one fish meal if you are pregnant or trying to become pregnant. In this case buying either mercury controlled fish or fish oils may in fact be the better choice  – I mean: "Better save than sorry", right?

Speaking of fish oil, there is an increasing trend towards krill oil as the "hype" omega-3 supplement. A trend of which you, as SuppVersity readers know that it appears to be unwarranted, although krill oil has the advantage of providing a large amount of the omega-3 fatty acids in their phospholipid-bound form (learn more in a previous SuppVersity article).

Figure 5: Plasma, liver and white adipose tissue (WAT) levels of triglyceride (TL) and phospholipid varieties of DHA+EPA after 9 weeks on HFD diet with (w3TL or w3PL) or  w/out 30mg/kg chow DHA + EPA (Rossmeisl. 2012)

Compared to triglycerides, the phospholipid-bound version is easier to assimilate. Accordingly, it is not very surprising that Rossmeisl. et al. (2012) were able to show that phospholipid-bound long-chain omega-3 fatty acids increase the plasma and liver omega-3 content to a significantly greater degree than the same amount of triglyceride-bound omega-3 fatty acids. An effect that was – at least in rodent studies – associated with a significantly more pronounced reduction in fat cell size and insulin sensitivity (Rossmeisl. 2012).
A more recent study by Tillander et al. (2014) adds to the evidence that krill oil may have an edge over fish oil, as an anti-NAFLD agent, because it will epigenetically reduce the fatty acid synthesis in the liver (read more).
 
The very ability to reduce the synthesis of fatty acids in the liver makes krill oil particularly interesting for overweight and obese people.

The increased fatty acid oxidation in response to the ingestion of fish oil (vs. krill oil) the researchers observed in the same study, on the other hand, may be something that could be of interest for lean individuals who are trying to lose weight (learn more in previous SuppVersity article).

Fish or krill? It depends... The previously presented evidence does thus make one thing very clear: It is more than likely that it will depend on your goals and current health status which of these omega-3 sources you should prefer. Overall, there is yet still a paucity of independent research, which is why I would not be surprised if the previously made conclusions were refuted by future studies.

If not weight loss, but muscle gains and fat loss are your goal, though, neither fish nor krill oil will do - at least not in the absence of one of the previously mentioned synergists: Fish protein!

Fish protein, an overlooked anabolic?

What wanna-be bobybuilders need is protein. Fish protein, to be precise. In 2009, for example, Ramel et al. were among the first to observe that using fish, or more specifically cod protein as the major protein source in the diet of their overweight subjects would yield improved outcomes in terms of fat loss and lean mass retention (Ramel. 2009; see Figure 6).

Figure 6: Decreases in anthropometric measurements after the 8-week intervention with isocaloric energy reduced diets having in obese subjects consuming no, three or five servings of lean fish per week (Ramel. 2009).

It is thus quite obvious that there must be something special to fish proteins more common dietary protein sources do not provide.

This hypothesis is also supported by previous evidence from rodent studies. One of these studies that was conducted by Frédéric Tremblay et al. (2003) at the Laval University Hospital Research Center suggests that the benefits may be related to the potent anti-inflammatory effects of fish proteins, which will thus increase the muscular insulin sensitivity and favor fat over muscle loss and muscle over fat gain.

A more recent study by Vikøren et al. (2013) seems to confirm this hypothesis.

The overweight adults who participated in the corresponding experiment experienced significant improvements in glucose metabolism, increases in lean and decreases in fat mass, when the scientists added 3 g of fish protein per day to their diets for the first 4 weeks and 6 g/d for the last 4 weeks of the 8 week intervention.

Figure 7: Macronutrient composition of the diets at baseline, after 4 weeks and 8 weeks and changes in body composition compared to baseline (Vikøren. 2013 - learn more in a previous SuppVersity article)

What is particularly noteworthy about this study is the fact that these effects occurred in spite of the fact that "[p]hysical activity and energy and macronutrients intake did not change during the course of the study" (Vikøren. 2013).

More recent evidence from a rodent study by Kawabata et al. (2014) strengthens the "anti-inflammatory" hypothesis. In their experiments, the researchers compared the effects of casein and fish protein in a tightly controlled dietary intervention and found similar increases in muscle mass and improvements in glucose metabolism in their hairy subjects as Vikøren et al. did one year before in overweight adults (learn more in a recent SuppVersity article).

Why don't we use our consumer money to force producers to make a change? I hope my previous elaborations have made it clear that living off fish as your only protein and fat source in the diet is probably not the best idea. On the other hand, similar issues with antibiotics (ab)use, persistent organic pollutants (POP) and even mercury exist for other foods, as well – with the exception of antibiotics which are only used to produce animal products all these pollutants can also be found in veggies and fruits (so no "vegan advantage").

We would thus be good advised to use our most powerful weapon, i.e. consumer money, to steer the food industry away from doing everything to cut the production costs and buy fish from those farms that don't use cheap poultry instead of fish oils, intoxicate the water with antibiotics and buy the cheapest, yet POP-laden food from questionable sources in China to feed their fish.

Time to draw some conclusions: Based on the existing evidence there is no reason to shy away from either fish consumption, in general, or the consumption of farmed fish, in particular. The overwhelming majority of epidemiological evidence indicates that consuming two servings of fatty fish a week will have nothing but beneficial effects on your overall health and that in spite of the fact that the fish was not controlled for organic or inorganic pollutants in any of these studies.

Whether it makes sense to consume large quantities of fish on a daily basis is yet as questionable as the routine use of fish oil supplements. Most of us will be able to cover our fundamental omega-3 needs with the previously mentioned two servings of fish per week. Consuming more than that in supplemental form is – in my humble opinion – not necessary for healthy individuals, unless they need to balance their exuberant intake of omega-6 fatty acid from large quantities of vegetable oils and processed foods in their diets –both products of which I highly recommend that people limit their intake to a minimum.

Moreover, imbalanced diets that are dominated by a single food source have repeatedly been shown to increase one's risk of running into severe health problems in the long run. So why don't we combine fish with dairy products, grass fed beef, pork and vegetable protein sources to create a varied, tasty, health and physique promoting high protein diet we can follow for the rest of your lives, instead of looking for the one "superfood", of which I would hope that most of the people who read this interview will know by now that it doesn't exist, anyway.

References:

• Brazionis, Laima, et al. "The effects of fish or fish oil on the omega‐3 index." Nutrition & Dietetics 69.1 (2012): 5-12.
• Berntssen, Marc HG, ANNE‐KATRINE LUNDEBYE, and Bente E. Torstensen. "Reducing the levels of dioxins and dioxin‐like PCBs in farmed Atlantic salmon by substitution of fish oil with vegetable oil in the feed." Aquaculture Nutrition 11.3 (2005): 219-231.
• Easton, M. D. L., D. Luszniak, and E. Von der Geest. "Preliminary examination of contaminant loadings in farmed salmon, wild salmon and commercial salmon feed." Chemosphere 46.7 (2002): 1053-1074.
• Hausken, Trygve, et al. "High Consumption of Farmed Salmon Does Not Disrupt the Steady State of Persistent Organic Pollutants (POP) in Human Plasma and Adipose Tissue." Journal of Toxicology and Environmental Health, Part A 77.20 (2014): 1229-1250.
• Ibrahim, Mohammad Madani, et al. "Chronic consumption of farmed salmon containing persistent organic pollutants causes insulin resistance and obesity in mice." PloS one 6.9 (2011): e25170.
• Mervish, Nancy, et al. "Dietary predictors of urinary environmental biomarkers in young girls, BCERP, 2004–7." Environmental Research 133 (2014): 12-19.
• Mozaffarian, Dariush, et al. "Cardiac benefits of fish consumption may depend on the type of fish meal consumed the cardiovascular health study." Circulation 107.10 (2003): 1372-1377.
• Nichols, Peter D., et al. "Readily available sources of long-chain omega-3 oils: is farmed Australian seafood a better source of the good oil than wild-caught seafood?." Nutrients 6.3 (2014): 1063-1079.
• Rawn, Dorothea FK, et al. "Persistent organic pollutants in fish oil supplements on the Canadian market: polychlorinated biphenyls and organochlorine insecticides." Journal of food science 74.1 (2009): T14-T19.
• Rossmeisl, Martin, et al. "Metabolic effects of n-3 PUFA as phospholipids are superior to triglycerides in mice fed a high-fat diet: possible role of endocannabinoids." PLoS One 7.6 (2012): e38834.
• Tillander, Veronika, et al. "Fish oil and krill oil supplementations differentially regulate lipid catabolic and synthetic pathways in mice." Gene expression 24 (2014): 28.
• Tremblay, Frédéric, et al. "Dietary cod protein restores insulin-induced activation of phosphatidylinositol 3-kinase/Akt and GLUT4 translocation to the T-tubules in skeletal muscle of high-fat-fed obese rats." Diabetes 52.1 (2003): 29-37.
• Vikøren, Linn A., et al. "A randomised study on the effects of fish protein supplement on glucose tolerance, lipids and body composition in overweight adults." British Journal of Nutrition 109.04 (2013): 648-657.
• Virtanen, Jyrki K., et al. "Serum long-chain n-3 polyunsaturated fatty acids and risk of hospital diagnosis of atrial fibrillation in men." Circulation 120.23 (2009): 2315-2321.
• Wei, Xi, et al. "Assessment of risk to humans of bisphenol A in marine and freshwater fish from Pearl River Delta, China." Chemosphere 85.1 (2011): 122-128.
• Yess, N. J. "US Food and Drug Administration survey of methyl mercury in canned tuna." Journal of AOAC International 76.1 (1993): 36.

Study on Krill Powder Suggests: There is More to Seafood Than Fat - Can Krill Give You What Fish Oil Can't? Plus: Krill Protein's EAA Content More Than an Able Match to Whey

If you listened to the SuppVersity Science News Round Up on Super Human Radio, yesterday, you may remember that the color of food can tell you something about it's antioxidant activity... well, guess what: It's the lipid-soluble pigment and potent antioxidant astaxanthin that gives krill its "healthy" orange-red color.

In a way this post could be regarded as a follow-up on yesterday's news about the profound weight-loss effects of high dose EPA (and to a lesser degree) DHA supplementation. After all, parts of the supplement industry have been working hard on establishing krill oil as a more efficient alternative for regular fish oil (see "Neptune Krill Oil, the New or Better Fish Oil?"). And in a way, the Rossmeisel study, I had in the news back in June 2012, would support this claim, since one of the proven benefits of krill oil actually is that it contains way more of the phospholipid variety of the long-chain omega-3 fatty acids that is more readily incorporated into the cells than the triglyceride variety from cheaper fish oils (see "Only Phospholipid Based DHA+EPA Reduces Fat Cell Growth & Elevated Insulin Levels Despite Obesogenic Diet").

Moreover, the results of a 2011 study by Burri et al. (Burri. 2011), which showed that other than fish oil, krill oil with an equimolar amount of EPA and DHA in it actally decreased the expression of those hepatic genes for gluconeogenesis and glycolysis which could be responsible for the problematic increase in glucose levels Poudyal et al. observed in response to high dose omega-3 supplementation (yesterday's news). Now, these observations certainly raise the question:

Can we ward off the negatives and maximize the benefits by using krill instead of fish?

You can't eat krill? Fraser Lewry's recipe for krill fried rice looks very real (and delicous) to me

The results of a very recent study from Norway appear to hold the answer to this question. Moreover, the fact that the researchers did use krill powder instead of the krill equivalent to fish oil, which was by the way regarded mostly as an unwanted waste product that was left over, when McDonald's & Iglu picked up the fish fillets for their Fish Macs and Captain Iglu (R) Fischstäbchen, actually sparks another intriguing question: Wouldn't it be more prudent to eat the whole fish, or in this case whole krill (powdered or not), anyway?

Now, while we will come back to the question of "eating whole krill" later, let's initially take a closer look a the experiment Bjorndal et al. conducted. The scientists two groups of particularly inflammation prone transgenic male mice of a C57BL/6 strain which constitutively expresses high TNFα (tumor necrosis factor-alpha aka cachexin, or cachectin) levels iso-caloric "high fat" diets. Half of the animals were randomized to the notorious high carbohydrate + high fat diet you usually see in studies like these, the other had parts of the protein and fats replaced with the protein and fat from krill powder (see figure 1 for more details).

Figure 1: The composition of the experimental diets (Bjørndal. 2012).

From the "if it fits your macros" perspective, this may look like a minor, negligible change. Over the course of the six weeks the experiment lasted, it did however make a huge difference, as far as the rodents' ability to handle the lipid and energy overload was concerned. And those differences were, as the researchers had already expected, particularly pronounced in the liver:

"The liver of mice fed the krill powder diet displayed increased β-oxidation, reduced lipogenesis, and reduced cholesterol- and glucose metabolism compared to high-fat fed mice, resulting in improved plasma and hepatic lipid levels." (Bjørndal. 2012)

In short, the provision of the krill based lipid + protein mixture affected the lipid metabolism, the expression of genes involved in glucose metabolism and the fatty acid composition in plasma and liver of the animals, while keeping the mitochondrial respiratory electron transport chain in liver intact.

Figure 2: Graphical illustration of statistically significant changes in hepatic gene expression (colors indicate involvement in glucose, cholesterol or fatty acid metabolism; center) and corresponding downstream effects on plasma lipids (small graphs on the right; created based on data from Bjørndal. 2012)

However, even though we see beneficial effects on lipid metabolism, the absence of beneficial effects on blood glucose despite the presence of the previously observed (Burri. 2011) and with the study at hand now confirmed beneficial effects on the expression of respective genes in the liver makes it quite clear that krill oil, just like fish oil cannot make up for the sheer energy overload of the typical western diet (see yesterday's news).

How come this sh*t doesn't work?

And what about the protein in krill powder? Since we don't have a direct comparison to a krill oil only supplement it is difficult to tell, whether the protein content of the powder used in the study at hand did actually make a difference, also because we do have evidence from previous studies (e.g. Burri. 2011) that krill oil alone elicited similar beneficial effects on the hepatic gene expression. Nevertheless,the favorable amino acid profile of krill protein concentrates (see figure above; data based on Gigliotti. 2008 and Sindayikengera. 2006), alone would suggest that the powder has way more to offer than just the oil.

With the increased energy expenditure from fat in response to both krill and fish oil, comes a lower reliance on glucose as a fuel source. Therefore, more of the sugary glue that makes an excellent fuel, but a very bad lubricant, will remain floating around in the blood, so that the unquestionably impressive >50% reduction of hepatic glyocogen breakdown and the corresponding -45% reduction in gluconeogenesis (see figure 2, green hexagons) are probably just enough to compensate the decreased glucose oxidation, so that the overall amount of glucose that's floating around freely in the blood of the krill oil / or powder supplemented animals will remain the same (with fish oil, and in the absence of these epigenetic changes, it will even go up!).

Bottom Line: While krill powder appears to have the edge over plain fish oil, it's use is yet likewise no panacea for all the ailments of the metabolic syndrome. 

The impressive amino acid composition of the protein fraction in krill powder (see information box on the right), as well as Yamada et al.'s 2011 observation that an obviously fat-free, since water soluble krill extract directly antagonizes triglyceride accumulation (=increase in fat content) in adipocytes by suppressing PPARγ and C/EBPα expression (Yamada . 2011), still speak in favor of my initial hypothesis that there is more healthy stuff in krill (and fish) than EPA, DHA & the rest of the omega-3 fatty acid megillah, so to say.

References:

• Bjørndal B, Vik R, Brattelid T, Vigerust NF, Burri L, Bohov P, Nygård O, Skorve J, Berge RK. Krill powder increases liver lipid catabolism and reduces glucose mobilization in tumor necrosis factor-alpha transgenic mice fed a high-fat diet. Metabolism. 2012 Oct;61(10):1461-72.
• Burri L, Berge K, Wibrand K, Berge RK, Barger JL. Differential effects of krill oil and fish oil on the hepatic transcriptome in mice. Front Genet. 2011;2:45. Epub 2011 Jul 12.
• Gigliotti JC, Jaczynski J, Tou JC.  Determination of the nutritional value, protein quality and safety of krillprotein concentrate isolated using an isoelectric solubilization/precipitation technique Food Chemistry, Volume 111, Issue 1, 1 November 2008, Pages 209–214.
• Rossmeisl M, Macek Jilkova Z, Kuda O, Jelenik T, Medrikova D, Stankova B, Kristinsson B, Haraldsson GG, Svensen H, Stoknes I, Sjövall P, Magnusson Y, Balvers MG, Verhoeckx KC, Tvrzicka E, Bryhn M, Kopecky J. Metabolic Effects of n-3 PUFA as Phospholipids Are Superior to Triglycerides in Mice Fed a High-Fat Diet: Possible Role of Endocannabinoids. PLoS One. 2012;7(6):e38834. Epub 2012 Jun 11.  
• Sindayikengera S, Xia WS. Nutritional evaluation of caseins and whey proteins and their hydrolysates from Protamex. J Zhejiang Univ Sci B. 2006 Feb;7(2):90-8. 
• Yamada H, Ueda T, Yano A. Water-soluble extract of Pacific Krill prevents triglyceride accumulation in adipocytes by suppressing PPARγ and C/EBPα expression. PLoS One. 2011;6(7):e21952.

Fish and Krill Oil Both "Work" But Their Effects on Your Genes Are Far From Identical. Krill May Bet Better For the Obese, While Fish Acts as a "Fat Modulator" in Lean Folks

If krill oil is not fish oil 2.0 what is it good or even bad for, then?

For SuppVersity Veterans, it's no news that phospholipid-bound omega-3 fatty acids (as in krill oil) have a superior bioavailability compared to triglyceride bound ones (as in fish oil) - you've read about that in in June 2012 in an article titled "Phospholipid or Triglyceride" (go back and read it!). This and the fact that the latest paper from the Karolinska Institutet, in Sweden, the University of Bergen and the Haukeland University Hospital in Bergen, Norway, is yet another rodent study had me hesitate before I picked up Roy Nelson's suggestion to discuss the surprisingly differential effects of fish and krill oil on the tissue concentration and lipid metabolism of mice, not men.

As I previously mentioned, the low rate of incorporation of triglyceride-bound omega-3 fatty acids into the tissue of the Male C57BL/6J mice, which were kept on a high fat diet that contained 24% (wt/wt) fat (21.3% lard and 2.3% soy oil), or, alternatively, the same HF diet supplemented with FO (15.7% lard, 2.3% soy oil and 5.8% FO) or KO (15.6% lard, 2.3% soy oil and 5.7% KO) for 6 weeks, is eventually not surprising.

You can learn more about omega-3 & co at the SuppVersity

Fish Oil Makes You Rancid?

Are All Fats Bad For You?

N3/N6 Ratio Doesn't Matter on SAD Diet

MUFA & Fish Oil Don't Match

Fish Oil Doesn't Help Lose Weight

Rancid Fish Bad 4 Health

Eventually, you can think of the difference between phospholipid bound (P) and triglyceride bound (T) fatty acids with respect to their chances of being incorporated into your cells as bricks (P) and menirs (T). Obviously, the former can be used right away, to build a new home. The latter, on the other hand, have to be processed, before they can become part of a building - or, if we leave our analogy, your cells. If you have enough "stones" aka omega-3s - and the 5.8% fish oil in the diet obviously were more than enough - you will still end up at similar serum levels (obviously it's not exactly feasible to consume ~6% of your diet, i.e. at least 120kcal = 13g of fish oil, everyday; therefore bioavailability still is a clear advantage for krill oil).

Popping more than 10g+ of fish oil a day is madness. Making the right fish choices and eating those fish twice a week, on the other hand, is smart!

So if that's not really news, what makes the study news-worthy, then? Well, that's actually a good question, which takes me right to observation #2: While the allegedly bad arachidonic acid, the long-chain omega-6 counterpart to the celebrated omega-3 stars, EPA & DHA, of which the SU.FOL.OM3 Trial recently taught you that it's good for your brain (go back), was reduced with both oils, the krill oil, which is per definition less omega-3 dense (there are more non-omega-3 fatty acids in it) had decreased the levels of this (imho falsely vilified) "inflammatory" fatty acid and its elongation/desaturation products in plasma and liver to a significantly greater extent.

In conjunction with its effects on the expression of genes involved in the early steps of isoprenoid/cholesterol and lipid synthesis, the ability to "clear" the pro-inflammatory arachidonic acid from your blood makes krill oil the perfect choice for people who suffer from chronic inflammation.

None of the 20 agents in the list of anti-obesity agents is going to do the work for you, but they could help you "conserve" the results, keep you lean on a bulk and/or avoid the hazardous Yoyo effect when you go off a die.

Krill oil favors the storage of glucose as fat: There is another effect that makes krill oil particularly interesting for the average overweight pro-diabetic. As a recent study from the Iwate University reveals (Yamada. 2014), 8-HEPE and 9-HEPE two metabolites of the well-known omega-3 fatty acid EPA that are present in high amounts in krill oil are potent PPAR-alpha, -gamma and delta activator. With PPAR-gamma being the "fat storage" switch (learn more) this is fortunate for the (non-)obese diabetic for whom it will help him clear the glucose from the blood and store it in the adipose organ. For the lean athlete on the other hand, the 20 PPAR-gamma inhibitors, I listed in a previous article with the telling title " Fighting to Stay Lean? These 20+ Anti-Obesity Agents Have the Potential to Inhibit Fat Gain Right at the Cellular Level" would certainly be a better choice.

For fish oil, things look (not generally but) slightly different. While fish oil will also have an impact on arachidonic acid and cholesterol synthesis, the scientists found that its effects on the liver and the downstream effects on the levels of triglycerides,  phospholipids and the very low density lipoprotein (VLDL) in the blood, as well as their accumulation in the liver is significantly more pronounced for fish vs. krill oil.

It's not all gold that glitters like fish oil, but "Krill Red" ain't necessarily better either

If you look at the data in Figure 1, you will also realize that fish oil had visibly (carnitine palmitoyl transferase 1 CPT1, ACOX), but not significantly more potent effects on the activity of fat burning enzymes in the liver. In view of the fact that the net results in form of body weight gain where identical, it's yet not just statistically, but probably also practically irrelevant.

Warning: Fish oil can clog your liver, as well and the increase in fatty acid synthesis in the liver (FAS) you see in Figure 1 could actually explain the observations I report in "Too Much of a Good(?) Thing: When Fish Oil Starts Clogging Your Arteries and Fattening Up Your Liver." | read more.

Although, if you think of a high triglyceride scenario, the use of fish oil appears to be a better choice to reduce the amount of the "carbohydrates" among the fatty acids (trigs will usually rise in response to problems w/ glucose metabolism and drop rock bottom in most people who stop eating carbs).

Figure 1: Rel. changes (% of HF diet) in liver fatty acid metabolism (left) and body weight development (right) of the mice over the study period (calculated base on Tillander. 2014)

This "advantage" is in line with the differential expression of  genes involved in fatty acid modulation and transport in the intestine. Only the fish oil, yet not the krill oil diet had significant effects on these PPARα driven genes, of which we believe that they are responsible for the immediate benefits of fish oil supplementation on postprandial (after the meal) plasma lipid levels and β-oxidation (less fats are absorbed, more are burnt right away - the importance of this effect is yet, as Tillander et al. point out "likely to be small".

Make up your mind: I would not say that there is yet a "right or wrong" with respect to the ingestion of fish oil and other omega-3 fatty acids in supplemental form. You know my scepticism, but it's obviously up to you to make up your mind.

If you browse previous SuppVersity articles, you will realize that there are actually arguments for both supplementing with (sane!) amounts of fish oil and touching none of the fishy pills, at all.

Bottom line: Practically speaking, its superior bioavailability, as well as its potent effects the levels of arachidonic acid and its metabolites in your blood make krill oil the better choice for people with a high baseline inflammation level. For them, the reduction in arachidonic acid takes away the "fuel" to the fire that's burning the cell lines of their arteries and organs and that's - unquestionably - a good thing.

The increased propensity for fatty acid storage in the adipose organ (not in the liver!) that was observed by Yamada et al., as well as the higher expression of "pro-oxidative" genes in the liver of which you would expect that it goes hand in hand with an increase in fatty acid oxidation appears to make fish oil, the better choice for the healthier individual. This does yet not mean that I've changed my mind: I still don't think that taking more than max. 2g of fish oil per day is beneficial for an individual who trains, eats clean (=no processed foods) and consumes fatty fish at least once a week. For him, or her, I actually wouldn't suggest taking any fish oil.

References:

• Tillander et al. "Fish oil and krill oil supplementations differentially regulate lipid catabolic and synthetic pathways in mice". Nutrition & Metabolism 2014, 11:20 doi:10.1186/1743-7075-11-20
• Yamada, Hidetoshi, et al. "Hydroxyeicosapentaenoic acids from the Pacific krill show high ligand activities for PPARs." Journal of lipid research 55.5 (2014): 895-904.