Monday, May 6, 2013

Fish Oil Compromises, Fish Improves Adiponectin Levels in "Overweight, But Healthy" Individuals. Neither Promotes Weight or Fat Loss Within a 4-Week Study Period

Fish are smart, they tell you about the good things "omega-3" fatty acids will do, without pointing you to the fact that eating them will yield a more favorable DHA:EPA ratio than popping pills that are made from the same remnants of their deceased relatives the fishery industry has dumbed for decades.
With the vitamin D news the other day (go back), you are now probably thinking "hell, no Adel's other favorite topic to rant about"... an yes! You are right: I just like to rant against mainstream stupidity and one-size-fits-it all approaches everybody loves because they are so "easy"! Take your fish oil! And everything is going to be all right. Much easier and so much more compelling, than my advice to eat fatty fish at least once, better twice or thrice a week to promote, not magically achieve metabolic health.

And while you've heard about the anabolic and blood pressure lowering benefits of fish protein in previous articles, here at the SuppVersity, it is more than unlikely that you've already gotten wind of the latest study from the Smart Foods Centre, School of Health Sciences (you got to love that name!) at the University of Wollongong, New South Wales, Australia (Neale. 2013)... and that despite the fact that it took - just as with the egg study, showing only beneficial effects on blood lipids (learn more) - suspiciously long for the study to make it from an "accepted manuscript" into a print article in the scientific journal Metabolism.

Scaled fish or capped oils - is that even a question?

In what is by no means the first, and certainly not going to be the last paper comparing the metabolic effects of fish oil caps to the food item, the oil is supposed to be delivered with (the fish ;-), Elizabeth P. Neale and her colleagues recruited 18–65 year old volunteers, who were willing to consume fish, but had a low- or moderate habitual fish intake to begin with (<3x per week). The subjects had to have a BMI somwhere in-between 25 and 37 kg/m² and a chubby midline with awaist circumference of >94 cm for men, >80 cm for women. Exclusion criteria were pregnancy, diabetes mellitus, impaired renal function, smoking, not weight stable for the past six months, food allergies or habits inhibiting compliance with the study design, illiteracy and inadequate conversational English; plus, they were excluded if they were currently taking medications including thiazolidinediones, valproic acid, ACE in-hibitors, and glucocorticoids.This left the researchers with N=30 subjects who were randomized to consume either
  • fish providing 1.86 g of LC n-3 PUFA (812mg EPA +1044 mg DHA)per day -- three serves of 135 g salmon (Birds Eye Atlantic Salmon Fillets, Simplot Australia), two serves of 66 g sardines (adjusted for percentage fish in total canned product; John West Sardines in Tomato Sauce, Simplot Australia) and one serve of 55.1 g tuna (adjusted for percentage fish; John West Tuna Tempters Lemon and Cracked Pepper, Simplot Australia) per week, or
  • supplemental fish oil (Blackmores Omega Daily) containing the same amount of LC n-3 PUFAs, yet - and this is a consequence of the low DHA/EPA ratio in fish oil vs. real fish - 1055.1 mg EPA and only 744.9 mg DHA
for 4 weeks, on a daily basis. And while the participants in the supplement group were "not expressly told to avoid fish", they were not "encouraged to consume it in preference to other protein sources", either (Neale. 2013).

What did the scientists want to measure?

The primary outcome parameter of the study were the differential effects of fish and fish oil on the plasma total and high molecular weight adiponectin levels in overweight humans and, secondary, to identify the genetic variations in participant's ADIPOQand FTO genes that may influence that response.
Figure 1: Relative changes in weight, BMI, waist, body fat (%), glucose, insulin and EPA + DHA levels in serum from t = -2 weeks (i.e. before the 2-week run in in which the diets and activity levels were standardized to 25% protein, 45% carbohydrate, and 30% fat) to t = 4 weeks (Neale. 2013)
As the data in figure 1 goes to show you this did not stop the scientists from evaluation the effects the intervention had on anthropometric parameters (waist, body fat, etc.) of their subjects, as well. Neither of these, nor the effects on blood glucose and insulin showed any significant inter-group difference. If we discard the identical changes in the EPA and DHA levels of the subjects, the dietary / supplement intervention had absolutely zero effects on any of these "extra-parameters" - no weight loss, no visible improvement in glucose metabolism.

No reduction in body fat or waist circumference in with fish or fish oil

Reason enough to ask yourself, whether we should not go back to baseline and ask "is fish / fish oil even good for you"? Certainly not - or I should say, only if you put faith in the hilarious promises of "instant weight loss, improvements in glucose metabolism" and what not, if you finally jump aboard and take your "essential fish oil supplements" that are plastered all over the Internet. If you discard these advertisment claims or simply apply some critical thinking skills, it should be obvious that you got to content yourself with changes in your potential to shed fat / improve glucose metabolism by simultaneously committing to lifestyle that's juxtaposed to the way of living that has gotten you into all the trouble to begin with.
Figure 2: Total and high molecular weight adiponectin levels expressed relative to the levels after the 2-weeks run-in (left) and the ratio of the absolute values after 4 weeks (right; Neale. 2013)
The changes in adiponectin expression in figure 2 are such an indicator of a change in the potential of getting rid of the blubber, the high blood glucose - and it is obvious to see that fish oil is inferior to fish, when it comes to inducing these changes.
"The results of this study suggest that short-termconsumption of fish and fish oil supplements does not have the same effect on HMW adiponectin levels in overweight humans. [...] This was due to a small increase in HMW adiponectin in the ‘fish’ group, whilst the ‘supplement’ group exhibited a significant decrease in HMW adiponectin concentrations. A similar pattern was seen for total adiponectin; however this did not reach statistical significance." (Neale. 2013)
As mentioned in the previous paragraph, these changes were not associated with differential effects on body weight, insulin levels and body fat mass, all of which "remained relatively constant" (Neale. 2013)

Fatty acid content in g/100g of wild and farmed salmon (left) and respective omega-3 to omega-6 ratios; learn more about making the "right fish choices", here
Unfortunately(?), the underlying mechanisms behind the differential effects on HMW adiponectin are as of now not known. Neale et al. do yet also subscribe to the "synergy hypothesis" I alluded to earlier in the first paragraphs of this article. The proven benefits of fish protein on insulin sensitivity and chronic inflammation (Soucy. 1999; Ouellet. 2007; Pilon. 2011), as well as the "other components present in fish such as selenium and vitamin D [, which] have also been associated with a range of health benefits in humans" [Rayman. 2000; Garland. 2006)...

...Oh, no! I know what you are thinking now. "I got all those in my multi! And I guess whey will do just as well as fish protein..." - come on, are you serious? Synergy is about ratios, about competition, about ups and downs, about co-factors and adjuvants. It's not about a kitchen sink supplementation approaches that try to reunite what has been ripped apart in a helpless effort to "make things easier" for the lazy consumer who does not like his fish and does not want to spend some of his daily screen time on buying fresh foods and preparing them... sorry, now I am really ranting ;-)

Handpicked suggested reads:
  • 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 (read more)
  • Phospholipid or Triglyceride? What's in Your Fish Oil Caps? Only Phospholipid Based DHA+EPA Reduces Fat Cell Growth & Elevated Insulin Levels Despite Obesogenic Diet (read more)

  • Moroi M, Akter S, Nakazato R, Kunimasa T, Masai H, Furuhashi T, Fukuda H, Koda E, Sugi K, Jesmin S. Lower ratio of high-molecular-weight adiponectin level to total may be associated with coronary high-risk plaque. BMC Res Notes. 2013 Mar 6;6:83. 
  • Neale EP, Muhlhausler B, Probst YC, Batterham MJ, Fernandez F, Tapsell LC. Short-term effects of fish and fish oil consumption on total and high molecular weight adiponectin levels in overweight and obese adults. Metabolism. 2013 May;62(5):651-60.
  • Ouellet V, Marois J, Weisnagel S, et al. Dietary cod protein improves insulin sensitivity in insulin-resistant men and women: a randomized controlled trial. Diabetes Care 2007;30(11):2816.
  • Pilon G, Ruzzin J, Rioux L-E, et al. Differential effects of various fish proteins in altering bodyweight, adiposity, inflammatory status, and insulin sensitivity in high-fat–fed rats. Metabolism 2011;60(8):1122–30. 
  • Rayman MP. The importance of selenium to human health. Lancet 2000;356(9225):233–41.
  • Soucy J, LeBlanc J. The effects of a beef and fish meal on plasma amino acids, insulin and glucagon levels. Nutr Res 1999;19(1):17–24.