Friday, September 2, 2011

Obese Vegan Salmon!? Vegetable Oils and Proteins Reduce DHA and EPA Content by -28% and Increase Overall Adiposity and Triglyceride Levels in Atlantic Salmon.

Image 1: Could this be made of obes vegan
salmon? (img from
If you listened to yesterday's episode of Carl Lenore's Super Human Radio, you may remember that I repeatedly pointed out that "not all milk is created equal" and that milk quality is determined by food quality (if you want to read more about milk in general and colostrum in particular, I suggest you read last week's Ask Dr. Andro, as well). Today I am going to tell you about another of the industry's economic (in the monetary sense) ways of reducing the quality of animal foods in our foodchain - and we are talking about a food with a much better reputation than milk or beef: Salmon, the "heart-healthy cold-water fish" that is literally in on (or rather between) everyone's lips, lately.
Note: Salmon is explicitly mentioned in the "sample one-day menu" scientists at Colorado State developed according to the USDA dietary guidelines (Dietary Guidelines for Americans), so don't tell me you are not supposed to eat Norwegian fish, anyway, because you, my American friends, are supposed to have Grilled salmon, steamed broccoli, barley pilaf, low-fat milk and cake with fresh berries for dinner ;-)
Bente E. Torstensen and his (her?) collegues from the National Institute of Nutrition and Seafood Research and the Skretting Aquaculture Research Centre in Norway conducted an interesting experiment (Torstensen. 2011). For about a year, the researchers fed 6,000 smolt of Atlantic salmon (mean weight 355g) which had previously been randomly assigned to one out of three experimental + one control groups with diets containing...
  • maximal amounts of fish meal and fish oil (Control)
  • the "safe maximum replacement" of both fish meal and fish oil with plant meal (80% plant protein) and vegetable oil (70% vegetable oil) (80PP70VO)
  • half the maximum replacement with plant meal (40%) and maximal replacement with vegetable oil (70%) (40PP70VO)
  • maximum replacement with plant protein (80%) and half of the maximal replacement with vegetable oil (35%) (80PP35VO)
While the control diet obviously resembles what salmon, which primarily feeds on other fish, would naturally eat, the diet composition of group 2 remotely reminds me of what the food-industry has been feeding the less health-conscious masses in the US and Europe over the last decades. What... as a animal-loving vegan you are more interested in the fate of the poor salmon than in that of your sick and obese fellow human beings? Ok, here is what happened:
Maximum dietary VO [vegetable oil] and PP [plant protein replacements] increased visceral lipid stores, liver TAG, and plasma VLDL and TAG concentrations. Increased plasma TAG correlated with an increased expression of apoB100, indicating increased VLDL assembly in the liver of fish fed the high-plant protein- and VO-based diet.
Veganism, it turns out, ain't the preferable diet for salmon. Depending on which end of the dietary spectrum you belong to - the carnivorous hunter or the vegan gatherer -  you will probably now be asking yourselves one of the following questions:
  1. Hunter: "What does that have to do with me? I always knew plant proteins and oils are bad for you!"
  2. Gatherer: "What does that have to do with me? I don't eat salmon and the results from a 'fish-model' certainly won't apply to human beings!"
In isolation both the carnivorous hunter as well as the vegan gatherer appear right, when they ignore a prick like me citing the results of an insignificant fish study, the amalgam of both of these trains of thought does yet bring up a more unsettling question: What happens to the average health-conscious customer on a budget who thinks he is doing him/herself good by frying his economically raised, i.e. vegetable oil and protein fed, salmon in "healthy" vegetable oils and finishes dinner with a tofu dish? To be honest, I don't think we really need a study to answer that question. You just have to look at your peers to see the health consequences of eating sick animals and other vegetables that were either never intended for human consumption or have been (over-)processed beyond all recognition.
Figure 1: Relative changes in the fatty acid profile compared to "real", i.e. fish-fed, salmon after 1 year on vegetable oil and protein (data calculated based on Torstensen. 2011)
A pros pos "beyond recognition" if you have a closer look at the combined effects of vegetable oils and proteins on the fatty acid (figure 1) of the fish you will notice that industrially produced salmon fed with the "safe maximum replacement" dose of vegetable oils and proteins has little resemblance with the healthy food most consumers believe they were eating, when they buy "salmon" at the grocery store. Most obviously, the beneficial n3:n6 ratio of 7.6 in "real" salmon changed for the worse and ended up at roughly 3.0 after one year on a 80% plant protein 70% vegetable oil diet. Moreover, the individual composition of the fatty acids changed, as well. These changes include -28% reductions in EPA and DHA levels. After all, customers are left with something that looks like salmon, because it has been artificially colored, and tastes like "salmon", simply because 99% of the customers do not even know how "real" salmon would taste, because since the 1980s the ratio of wild-caught (real) salmon to farmed (fake ;-) Atlantic salmon has declined from 10:13 to 1:480 and fewer and fewer people have even had the chance to taste non-industrially produced salmon.