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Friday, February 27th, 2009
Midweek I wrote a short diary that can be read here. It was inspired by an article on MSNBC called: Want to live longer? You need this nutrient by Taras Grescoe. It is hands down the best article I’ve read on why we need omega 3’s in our diet and why all the ‘live like your ancient ancestors and eat a cow (really, how many ‘cows’ were there in the paleolithic age anyway?). I promised to expand on my comments during the weekly 2 potatoes diary which I’m moving back to Friday.. reasons below.
Reminder: I’m not a doctor I’m just a person on a journey just like you.
I’m sorry for bouncing this diary back and forth between Friday and Sunday. As I discovered last week when I missed writing the diary on Sunday too, I just don’t have much control over my life and time at this point and weekends are no more my own than weekdays now that my experiments are full speed ahead. (I passed my PhD’s qualifier exams!) That said, many more of you seemed to like the diary on Fridays. So, I will leave it where it started and just hope I can keep up my end of the bargain.
Now where were we.. oh yes, Omega-3’s. First let’s talk about what that means, I’m going to talk some chemistry but don’t get scared. Those of you that know more chemistry, feel free to skip ahead, I don’t want to bore you or insult anyone’s education. If you know your chemistry already and just want health info go to the prety blue flowers. If you’re sold on Omega 3’s already and just want good, ecologically sound choices head down to the fish.
Carbons can have four connections at one time and sometimes they can be connected to things multiple times. Think of it as if you are a chimpanzee and can hold onto things with your feet as well as your hands. You can hold onto four of your ape friends, or hold onto three friends and a tree limb, and sometimes you might decide to hold onto one friend with two hands leaving just your feet to hold onto other chimp buddies and this would be a double bond.
Fatty Acids are straight chains of carbon atoms meaning they are holding onto only 2 other carbons at most and are hanging onto little hydrogen atoms with their free limbs. They end with a carboxylic acid group written as COOH which means the last carbon is holding onto an oxygen with two hands, the next to last carbon with one foot and the last foot is holding onto an Oxygen with a hydrogen in it’s other hand. Oxygens, like humans can only hold onto 2 things with their hands.
Unsaturated fatty acids have at least one double bond within the carbon chain. Mono unsaturated fatty acids have one double bond, poly unsaturated fatty acids have two double bonds within the chain. All Omega’s (3, 6 and 9) are poly unsaturated.
The term Omega refers to the opposite end from that COOH end. Now we’re going to locate that double bond closest to the omega end. Being an Omega-3 means the last double bond is between the 3rd and 4th carbon counting from the omega end. An Omega-6 has it’s double nearest the omega end between the 6th and 7th carbon. I bet you can guess where the Omega-9 has it’s double bond…
While we’re here.. let’s talk about those pesky trans fats. Trans, means on opposite sides and it’s referring to the position that the hydrogen is in the two carbons involved in the double bond. Naturally occurring fats are in the cis position. See the picture:
As you can see the effect of twisting the hydrogens to opposites sides is to straighten the molecule out. Which is the same problem with saturated fats. Without that double bond the chain is straight and mostly flat and that seems to lend itself to laying down on your arteries, being inflexible because all the hydrogen wants to be as far apart as possible and other really bad things.
So now, what is an essential fatty acid? That’s a fatty acid that the human body doesn’t make and so you have to eat them. There are two for humans, LA (Linoic Acid-an Omega 6) and ALA (alpha Linoic Acid-an Omega-3). In theory, all the other fatty acids can be made but DHA and EPA are almost essential acids. That’s because although they can be made by humans from ALA very little actually IS made and therefore we really do need to eat them because we use far more DHA and EPA than we make from ALA.
So what’s wrong with Omega 6’s, we need them don’t we? Well yes we do, but only in a good ratio with Omega 3’s. The Omega 6’s and 3’s can be converted into other fats in their type… like LA being converted to another omega 6 arachidonic acid which is suspected of being an inflammatory agent. Omega 3’s are believed to be anti inflammatory agents explaining why you need to keep them in balance. There are studies showing this Omega 6 fatty acid in the brain causes depression. Depressed Rats have High Omega 6 concentration in Brain.
We examined the fatty acid (FA) composition of selected brain areas in an animal model of depression, the Flinders Sensitive Line (FSL) rat, and compared the findings to controls fed identical diets. In all brain regions studied, the concentration of arachidonic acid was significantly higher in the FSL rats: in the hypothalamus by 21%; in the nucleus accumbens by 24%; in the prefrontal cortex by 31%; and in the striatum by 23%. No significant differences were observed for n-3 PUFA, or for the saturated and the monounsaturated FAs. Our results confirm the existence of altered brain PUFA composition in an animal model of depression. The finding of increased arachidonic acid, an n-6 PUFA, rather than decreased n-3 PUFA, emphasizes the importance of both PUFA families in the pathophysiologic processes underlying depression.
It may exacerbate Alzheimer’s
The brains of normal mice and mice genetically engineered to have an Alzheimer’s-like condition were compared by the scientists. They found raised levels of a fatty acid called arachidonic acid in the hippocampus area of the brains of the Alzheimer’s mice (the hippocampus is a memory center that is severely affected by Alzheimer’s disease). Arachidonic acid is used to make the blood-brain barrier. It is this barrier that protects the neurons in the brain from being contaminated by toxins as it filters the blood stream entering it.
Dietary fish oil causes its prostaglandin-lowering effects through three different mechanisms, says Dr. Smith.
First, the much fewer prostaglandins are made from omega 3 fatty acids as compared to the other class of fatty acids in the body, the omega 6 family of fatty acids that originate in the diet from leafy vegetables and other plant sources.
Second, the omega 3 fatty acids compete with omega 6 fatty acids for the same binding site on the COX 1 enzyme that converts the omega 6 fatty acids to prostaglandin (which is why the COX 1 enzyme and its COX 2 cousin are the targets of anti-inflammatory drugs like ibuprofen). The more omega 3 fatty acids present to block the binding sites, the fewer omega 6 fatty acids are able to be converted to prostaglandin.
Third, although omega 3 fatty acids also are converted to prostaglandins, the prostaglandins formed from omega 3 are generally 2 to 50 times less active than those formed from the omega 6 fatty acids from dietary plants.
Among other things the Omega 3’s keep our cell membranes flexible and block inflammatory agents from moving into our cells.
The scientists found that two types of lipids in omega-3 fatty acids—protectins and resolvins—were the cause of the protective effect. To reach this conclusion, they studied four groups of mice with an altered gene making them obese and diabetic. One group was given an omega-3-enriched diet and the second group was given a control diet. The third group was given docosahexaenoic acid, and the fourth received only the lipid resolvin. After five weeks, blood serum and liver samples from the test mice were examined. The mice given the omega-3-rich diet exhibited less hepatic inflammation and improved insulin tolerance. This was due to the formation of protectins and resolvins from omega-3 fatty acids.
Anti diabetic properties of Omega 3’s
OK so let’s all agree we want more Omega 3’s in our diet and especially, we need DHA and EPA directly because we are very poorly equipped to do the conversion. The question becomes how. And hopefully how to do it in a sustainable ecologically sound way.
One thing we can try is to tweak our conversion ratio. The conversion of ALA to EPA and DHA is directly affected by how much competition for the required enzymes (desaturases which form double bonds and elongases which hook the short chains into longer ones) there is from Omega 6’s. Therefore, if you reduce the omega 6 content of your diet you can consume more plant generated ALA such as from flax seed (the king of ALA producers), broccoli, green leafy veggies. What are the worst offenders as far as Omega 6 content in the American diet? Animal products and processed foods–including lots of foods eaten by vegans! No one has it easy here. To be avoided: corn, cottonseed, peanut, safflower, sesame, soybean, sunflower oils and generic ‘vegetable’ oil and margarine.. and now you see why processed foods, like cakes, breads and fried foods, are such a problem.
Ultimately, the best thing to do is increase our consumption of algae and fishes and some shellfish. But it’s still not that simple. Our oceans are being harvested in unsustainable ways. Let’s start with which fish to avoid from a dietary standpoint:
First of all, skip most farmed fish. Remember the Tilapia fuss? Well that also includes catfish. While they don’t warn against farmed salmon and trout I’m going to flag ALL farmed fish as, get to know the farmer. The problem is that we’re doing the same thing to fish as we did to beef. We’re feeding them grains. Especially bad: corn. These jack the omega 6 levels so that the fish is no longer beneficial in our quest for a higher omega-3 to omega-6 ratio.
If you can find a farmer that’s feeding a natural feed and you trust…personally, I’m taking a pass.
Mercury: Many fish higher on the food-chain contain higher amounts of mercury due to bio accumulation. Thus you should restrict your intake of fish known to contain mercury to 1-2 times a week unless you’re pregnant or a young child in which case you should abstain all together. This means the sum total of your elevated mercury burdened fish should be 12 ounces inclusive of all mercury laden fish you’ve eaten… not two servings of tuna and two servings of cod!
PCB’s: Proving once again that our government is insane.. especially the FDA… farmed fish are governed by the FDA and wild fish are governed by the EPA. The amount of toxins allowed by the EPA is much less than that allowed by the FDA.. to the tune of 10X more PCB’s are allowed in farmed fish than in wild caught fish. I’m sure it’s a matter of convenience because most of those farming situations probably use PCB laced plastic piping. And farmers are trying to improve their methods, but right now, they aren’t good enough for me to recommend them.
Let’s cut to the chase!
What fish are good for you and ecologically sustainable?
Here’s the list, Omega-3’s are per 100 grams eaten:
Anchovies 1.48g
Mackerel (Atlantic not Spanish or King) 2.45g
Oysters 0.68g
Sablefish 1.66g
Sardines, Pacific 1.9g
Rainbow Trout 0.986g
Tuna canned albacore 0.95g
(Look for fish caught in the U.S. Atlantic by trolling or pole-and-line gear as they result in almost no bycatch.)
Farmed Caviar 6.6 g
Crab (1 time/month due to contaminants) 0.3g
If you want to read more on fish the Environmental Defense Fund has a great website on health and ecology info of the fish you eat.
* Albacore, bigeye, yellowfin and skipjack are resilient to fishing pressure because they grow quickly and reproduce often.
* Bluefin tuna, on the other hand, grow slower and take longer to reproduce. This, coupled with their exorbitant value in the sushi market, has led to severely depleted populations.
* Bigeye and yellowfin, also known as ahi, are common in sushi. Both types, along with bluefin, are high in mercury and should be eaten infrequently, if at all. (Our expert on mercury in tuna sushi.)
* Most tuna are caught by purse seines or longlines, which have moderate-to-high bycatch of seabirds, sea turtles and marine mammals.
* Pole-and-line caught tuna is less common but is a better environmental choice.
They also have a great deal of info on the safety of your fish oil choices.
I’ve been reading a lot of labels lately. Interestingly The Meijer’s brand of salmon, both red and pink, has more fat per unit weight than Demmings. If one assumes this is just because they use fattier cuts of fish then the amount of omega-3’s should increase correspondingly. By my estimation 43% more. It may be cheaper and better for you! Once again our efforts to reduce fat may be backfiring by demonizing the good omega 3 laden fish oils with the bad ones. I’ve been working with the buyer and the packer at Meijers trying to get down to the bare facts but they have not gotten back to me with the numbers in time for this dairy. I will update the information when I receive it, here or in a future diary.
And my favorite additive source: Krill oil
Truth in Blending statement: I use MegaRed but I don’t work for them and they don’t pay me.
Algae is the ultimate source of the good omega 3’s in fish. If you really want to avoid eating fish then you’ll need to go to the source. If you want to eat your algae then you want to pick up some Nori. That’s a flattened, dried red algae that’s frequently used in sushi and Asian soups as well as a common ingredient in ice cream! I have some Dulse Palmaria palmata) that I use in soups. You’ll have to poke around in a few Asian stores to find it though, you can’t get it at Penzeys!
Algae oils on the other hand are relatively easy to find. They don’t cause fishy burps, don’t kill anything above the plant level and seem sustainable. Hopefully, it’s not Soylent Green! I haven’t tried this yet. I’m still committed to trying to alter my diet through mainly consumption and not additives. But if I trip across these sometime I might try them out. How about you? Have you tried any of these? What’s your take?
Oh, and I’m recommitting to my diet tomorrow. I gained a lb instead of losing one this week. I have been sitting and reading too much, not being active enough and eating too much cheese! Time to get right!
