As eluded to in Part I, Unsaturated fats are broken up into two main categories: Monounsaturates, also called the omega-9 (w9) fatty acids, and Polyunsaturates. Polyunsaturates are further broken up into omega-6 (w6) and omega-3 (w3) fatty acids. It is within the polyunsaturates that we find the two essential fatty acids (EFAs), which the body cannot manufacture itself but are neccesary to preserve life and health. For this reason, they must be attained in the diet and, hence, are called "essential". They are linoleic acid (LA), an w6 fatty acid, and alpha-linolenic acid (LNA), an w3 fatty acid. These two are as essential to good health as any vitamin and should NEVER be deficient in the human body but, as we'll see, they may also have positive effects on muscle growth and strengthening.
In the proper quantities and balance the EFAs can...
Monounsaturates have been shown to raise high-density lipoproteins (HDL - the "good" kind of cholesterol) and potentially lower low-density lipoproteins (LDL - the "bad" kind of cholesterol). Metabolically, they are neutral, neither increasing or decreasing metabolic rate.
Before we get any further into the positive benefits of the EFAs, let's take a look at how they do what they do from a muscle strengthening/growth perspective.
One way that the EFAs impact the bodily environment is that they control and influence eicosanoid formation. Eicosanoids are short-lived, hormone-like substances that regulate many cellular functions in all human tissues. There are three types of them: Series 1, series 2 and series 3. Generally, the series 1s have been considered "good", the series 2s "bad", and the series 3s also "good". It's a little more complicated than that, but we'll get into that a little later. Let's start out with a look at the series 1s.
The main series 1 eicosanoid belongs to a subgroup of eicosanoids called prostaglandins. It is prostaglandin E1 (PGE1) and has the following positive actions:
The main series 2 prostaglandin, PGE2, on the other hand, causes water retention by promoting sodium retention in the kidneys and causes inflammation (which promotes higher cortisol levels - cortisol is an anti-inflamatory). Series 3 prostaglandins are thought to be "good" in that they prevent the production of series 2s.
However, it isn't quite as clear-cut as simply labeling the series 2s as "bad". Some series 2 eicosanoids actually counter the "bad" effects of the others series 2s, and so compensate, at least partially, for what would be considered "negative" effects. For instance, prostacyclin PGI2 counters some of the negative effects of prostaglandin PGE2 by inhibiting platelet aggregation and activating leukocytes (which is good). In addition, a couple of the series 2s are potent stimulators of muscle growth. When muscle cells are strenuously trained they release the series 2 prostaglandins PGE2 and PGF2-alpha. PGE2 increases protein degradation, but it also potently induces muscle satellite cell proliferation and infusion, leading to muscle growth. PGF2-alpha increases protein synthesis, suspectedly by increasing protein synthesis "efficiency" at the ribosomes. It also seems to destroy fat cells. (Is that possible support for the theory of "spot reduction" that the old-timers swore by? Train a muscle more often, release more PGF2-alpha, destroy more fat cells?! Incidently, recent research has given scientific support to the concept of "spot reduction".)
So where do the EFAs come in? Well, the EFAs are the substances out of which the prosatglandins are made. Linoleic and alpha-linolenic acid are the "parents" of all the eicosanoids. Linoleic acid (LA) is converted into gamma-linoleic acid (GLA) in the liver. GLA is then converted to dihomo-gamma-linoleic acid (DGLA), which is then either converted to the series 1 prostaglandins or arachidonic acid (AA). The series 2 prostaglandins are made from AA. The series 3 prostaglandins are made from alpha-linolenic acid (LNA) by the following path: LNA is converted into stearidonic acid (SDA - also known as octadecatetraenoic acid), SDA is converted to eicosatetraenoic acid (ETA), ETA is converted to eicosapentaenoic acid (EPA) and EPA is converted to docosapentanoic acid then docosahexanoic acid (DHA). (DHA also goes "backwards" to become EPA). The series 3 prostaglandins are then made from EPA. EPA blocks both the conversion of DGLA to AA and the conversion of the AA into PGE2 (incidently, so does regular aspirin) and has also been shown to have a significant positive effect on the integrity of muscle cells after exercise stress. Also, high levels of PGE1 prohibit the production of series 2 prostaglandins.
If you look closely at the above figure you'll notice that many of the enzymes involved the various conversions serve several purposes ...so a balance must be struck. You really don't want to excessively produce any one series of prostaglandins at the expense of the others, because they all have their essential purposes. For instance, PGE1 improves insulin sensitivity and speeds muscle recuperation after training, but PGF2-alpha is a potent inducer of muscle growth. You don't want to produce excessive amounts of one while creating a shortage of the other.
Now here's the interesting part, as shown in the figure, the foods we eat can contain AA, GLA, SDA, EPA and DHA (as well as the EFAs). The optimum diet, aimed at producing vibrant strength, health and muscular development, should include a variety of these foods regularly. It is also interesting to note that animal fats (as found is meats and milk), organ meats (for example, liver), eggs and butter, which have traditionally been staples of the drug-free bodybuilder's/strength athlete's diet, all contain arachidonic acid. Thus leading to the production of the series 2 prostaglandins which are crucial to the muscle growth process. Liver, other organ meats, eggs and cod liver oil also contain fatty acids leading to the production of the "good" series 3 prostaglandins.
Here's a list of foods providing good sources of these fatty acids. The percentage listed in brackets after the oil, fat or food indicates how much of it's total fatty acid content is the fatty acid in question.
It's also very important to realize that many dietary, medical and lifestyle factors can influence eicosanoid pathways. For instance:
And here are a few things that you may not have control over:
Here are some things that positively affect the prostaglandin pathways:
Here's a list of do's and don'ts for promoting healthy prostaglandin pathways from Dr. Mary Enig and Sally Fallon:
So how much of these oils do you need to promote the healthy balance that I spoke about above? First of all, you have to keep in mind that there exists a balance between LA and LNA. Too much of one can interfere with the eicosanoid pathways of the other, or even the proper metabolism of itself. Some researchers, including Dr. Udo Erasmus, have reasoned that because bodily enzymes convert w6s only about one-fourth as efficiently as they do w3s, we should take a 4:1 ratio of LA to LNA. Others, however, prefer a lower ratio of LA to LNA, even as low as 1:1. Perhaps a better approach is to determine the amount of each type of oil that is necessary for maximum health and let the exact ratios take care of themselves.
It should also be realized that the North American diet contains an abundance of w6s but is notoriously low in w3s - 80% of the population is deficient in LNA (and also EPA, DHA and the other LNA metabolites). In fact, most westerners have w6:w3 ratios of 20:1 to 50:1! The first thing most people should do, if they want maximum results from their training, is to stop eating so many w6s. This can be a difficult task, given the current state of the vegetable/grain oil-dominated western grocery industry.
Unfortunately, the optimum amounts of these fatty acids have not been established for athletes and people in intense physical training. So, to support our weight training we're left to start with the established optimum amounts for non-athletes and modify that with the experience of drug-free lifters. Final recommendations will be made in Part III of this series.
The following is a list of oils and foods that supply 7 grams of linoleic acid, 3.5 grams of alpha-linolenic acid and up to 3.5 grams of combined EPA and DHA.
|Sunflower oil||2.0 tsp|
|Evening Primrose oil||2.0 tsp|
|Corn oil||1.0 tbsp|
|Borage oil||2.0 tbsp|
|Flax Seed oil||2.0 tbsp|
|Canola oil||2.5 tbsp|
|Olive oil||5.0 tbsp|
|Flaxseed oil||1.5 tsp|
|Canola oil||1.5 tbsp|
|Walnut oil||2.0 tbsp|
|Soybean oil||3.0 tbsp|
|Cod Liver oil||1.0 tbsp|
|Lake Trout||5.25 oz.|
In Part III of this series I'll take a look at the formation of the steroid hormones from cholesterol, throw some miscellaneous practical advice in there, and wrap up with some final recommendations on dietary fat intake.