by Brad Dieter, MS, CISSN, CSCS.
Protein and fat are the two obligatory substrates people have to consume in order to sustain life, while carbohydrates are not. In layman’s terms, you have to eat fat and protein to live, while carbohydrates are just extra, you really do not need them to survive. If fat is entirely excluded from the diet of humans, a condition develops that is characterized by retarded growth, dermatitis, kidney lesions, and early death1.
Research has shown that these conditions are reverse when subjects consumed certain unsaturated fatty acids, namely the Omega-3 and Omega-6 PUFA’s. These specific PUFA’s cannot be synthesized in the human body and must be acquired in our diet, thus, these are the essential fatty acids (EFA’s). The names of these PUFA’s are linoleic acid (LA), an Omega-6, and alpha linolenic acid (ALA), an Omega-3. From these two PUFA’s our body can manufacture the subsequent compounds necessary for our bodies to properly function. . . . at least that is what science says, but we will see in a later post why LA and ALA may not be the effective way to obtain the “essential” fats that we need to include in our diet.
What Exactly Do These “Essential Fats” Do?
The main role EFA’s play in the body are for formation of cell membranes and are precursors to a group compounds known as Eicosanoids. The Eicosanoids are long (20 carbons in length), highly unsaturated fatty acids and form prostaglandins (PG’s), thromboxanes (TBX’s), and leukotrienes (LK’s). Ok, sorry for the big scientific terms and I will try and limit using them, but these are big time players in maintaing your body. The PG’s, TBX’s and LK’s are involved in some important physiological processes, including: 1) lowering blood pressure, 2) blood platelet aggregation (clotting), 3) immune response and regulation, 4) smooth muscle contraction (i.e. the muscles involved in breathing, blood vessels, and your digestive system), and 5) they act as signals all over the body.
I know what you are thinking, Holy Smokes, I did not know fats did all those things for you. Now compare the roles the many different roles that fats play in the human body when you compare it to the myopic role of carbohydrates. That is absolutely amazing if you ask me, but then again I am a huge nerd and love this stuff.
It’s pretty apparent that Omega-3 and Omega-6 EFA’s are pretty darn important… but are they equal? Well, lets find out.
Omega-3 Vs. Omega-6
Omega-3 EFA’s differ from Omega-6 EFA’s in that their first double carbon bond occurs at the location of the 3rd carbon from the methyl end of the chain where in the Omega-6 , EFA’s, that first bond occurs at the 6th carbon. Big nerd terms aside, this just means that they play quite different roles in the body.
How different you ask? Well to answer that as simply as possible, the end products of Omega-3 EFA’s are generally considered anti-inflammatory and are reported to have hypolipidemic (lowering lipids/fat) and antithrombotic (preventing excess clotting) effects, while Omega-6 EFA’s are considered pro-inflammatory in nature. Here is a great diagram that shows you the end products of the Omega-6′s and the Omega’s.
Clearly, the EFA’s are not equal, they play complementary roles to each other. Just like everything else in the world, too much of one, and not enough of the other has some serious consequences. . . In the case of the EFA’s, too much Omega-6 increases inflammation.
INFLAMMATION
Ok, so you eat too much Omega-6 EFAs and have a little more inflammation than you should… Who cares is probably what you are thinking. Well, I care, and I care a lot. The whole reason I write this blog, went to grad school, and spend my free time learning about the human body is because I care about all of you and your health!
That being said, what is the big deal? Inflammation is a normal physiological response that is crucial to maintaining health; however excess inflammation, or uncontrolled inflammation leads to impaired function, and disease2. Inflammation is a critical component in the development of cardiovascular disease, THE NUMBER ONE KILLER IN THE WORLD.
Why is cardiovascular disease so rampant? Well I believe a large part of it has to do with the inflammatory nature of the standard western diet, and both epidemiological studies and clinical studies can substantiate this belief. This is where we can really push the “paleo”/ evolutionary view on nutrition.
Quick recap, Omega-6 EFA’s are generally pro-inflammatory while Omega-3 EFA’s are generally anti-inflammatory in nature. The standard Western Diet has a Omega-6:Omega-3 ratio of anywhere from 10:1 to upwards of 25:1, where our Paleolithic ancestors had a diet that was closer to 1:1. . . . Do you see the stark differences?
The average American consumes a diet that promotes an inflammatory state 10-25 times great than an anti-inflammatory state. Holy COW, no wonder we all drop dead of diseases linked to inflammation. Why is the Omega-6: Omega-3 ratio so out of control? Here is a list of foods high in Omega 6 and Omega 3 and you can see what we eat a lot of and what we eat a little of.
| Omega 6 | Omega 3 |
|
Corn oil
Safflower Oil Soybean Oil Almonds Cashews Sunflower Seeds
|
Marine Algae Salmon Mackerel Sardines Grass-fed meat Flax Seed |
Are you beginning to see why the whole “Fish Oil” movement has taken hold in the past decade? Fish oil supplements are high in Omega-3 and virtually void of any omega-6, which helps us balance out the Omega-3:Omega 6 ratio. I am not generally a big supplementation person, but in light of these facts and the state of the western diet, I definitely suggest people take fish oil supplements high in DHA and EPA. In fact, there have been a number of clinical trials assessing the benefits of dietary supplementation with fish oils in several inflammatory and autoimmune diseases in humans, including rheumatoid arthritis3.
Think about how much you just learned in about 10 minutes of dedicated reading! Thanks for tuning in this week, I am excited about the next post where we tackle another amazing fat, CHOLESTEROL! I am also going to come back to the EFA’s and explain why EPA and DHA are so essential and why just eating ALA (remember the basic precursor to EPA and DHA) doesn’t quite cut it.
References
1) Gropper, S. S., Smith, J. L., & Groff, J. L. (2005). Advanced Nutrition and Human Metabolism. Belmont, CA: Thomson Wadsworth.
2. Chiang, Y., Haddad, E., Rajaram, S., Shavlik, D., & Sabate, J. (2012). The effect of dietary walnuts compared to fatty fish on eicosanoids, cytokines, soluble endothelial adhesion molecules and lymphocyte subsets: a randomized, controlled crossover trial. Prostaglandins, Leukotrienes and Essential Fatty Acids , 87, 111-117.
3) Simopoulos, A. (2002). Omega-3 fatty acids in inflammation and autoimmune diseases. Journal of the American College of Nutrition , 21 (6), 495-505.
BIO – Brad is a Ph.D. student at the University of Idaho in Exercise Science. He received his M.S. degree in biomechanics from the University of Idaho and is a Certified Sports Nutritionist (CISSN) and a Certified Strength and Conditioning Specialist 
(CSCS). He has experience as a nutrition and fitness consultant, a collegiate strength coach, and a trauma representative in the orthopedic industry. Outside of school research, his research interests are in developing a better understanding of the nutrition, health, and performance axis and real world application of that knowledge.
