Omega-3 Fatty Acids are not just some kind of "Alternative anti-depressant fad" like St. John's Wort, and eating a tablespoon a day of flax oil (as most supplements recommend) is going to do far more good than harm. Omega-3s are essential fatty acids, meaning they play vital, necessary roles within the body. Strangely enough, the entire medical community can agree that "EFAs" really are necessary to survival, yet the FDA has not required food producers to label the EFA content of their product, nor have they established a recommended daily allowance of EFA. This may be because it would be impossible for them to actually come up with a way to meet the requirement without supplementation, which the FDA tends to scorn. The reason they are becoming popular is simple -- people are finally learning about them. Chances are, you don't consume enough of them, and you probably consume too much of what you don't need.

It's true that there are "good fats" and "bad fats." Though it is true that anything is dangerous in excess, it is also true that there is a huge difference between consuming fats that are absolutely necessary, and consuming fats that serve no useful role in the body. Strangely enough, the American diet emphasizes excessive consumption of unnecessary and potentially dangerous trans fatty acids, which are present in the "partially hydrogenated oil" that is present in nearly every form of processed food found at the supermarket, restaurant, and home kitchen. It is true that one should aim to keep their "total fat" consumption below 30% of their total caloric consumption. But this doesn't mean that any single source of fat is fine. A varied diet is necessary, and if one is unaware of Omega-3s, they are not likely to consume enough of them. Thousands of years ago, humans consumed large amounts of Omega-3s by eating the flesh of animals that lived on a free-range, varied diet. Most of today's corn and soy-fed animals are just as deficient as we are. Fortunately, it is possible to buy free-range fed meats in some areas. My local supermarket has "Free Range Omega-3 Enriched Eggs" that cost a little more, but contain far more Omega-3 and Vitamin E than standard eggs. It is probably not a good idea to thoroughly scramble the eggs, as this will oxidize most of the healthy Omega-3s. Instead, fry the egg on both sides in a little olive oil or non-hydrogenated margarine (e.g. "Smart Balance(tm)" or "Spectrum Essentials(tm)") and enjoy the yolky goodness on some toast. Most of the fat, good or bad, is in the yolk.

Omega-3s can not be manufactured in the human body, so they must be consumed from other food sources. The best sources include ground flax seeds, hemp seeds, certain nuts such as walnuts, certain varieties of algae and seaweed, and coldwater, freshwater fish like salmon. Omega-3s are used in the creation of cell membranes. They are polyunsaturated, meaning they are very fluid at room temperature, and can remain fluidlike at temperatures approaching freezing. Due to their polyunsaturated structure, they are sensitive to heat and light, and must be extracted from seeds using "cold expeller press" techniques. Even this generates some heat, potentially destroying a percentage of the fat, possibly oxidizing it into something that is actually detrimental to your health. The best way to go is fresh-ground flax seeds. Don't grind them in advance, just grind enough to consume at once. While they are in seed form, they are useless to you, but they are also protected from oxidation. Once they are ground, they begin to deteriorate. This is why I think it's pointless to buy anything that contains ground flax. Flax is a better Omega-3 source than hemp, unless one manages to eat a lot of Omega-3 rich food already. The reason is simple; flax oil is mostly composed of Omega-3, hemp oil is mostly Omega-6. Hemp oil contains far more Omega-3 than soy oil, but flax oil tops them all. Have some fish too, if possible -- fish and other sea-based sources are more rich in DHA and EPA, which are suspected of serving important roles in brain development.

Their inherent polyunsaturated "fluidity" is essential to the function of the selectively permeable membrane that covers every cell in your body. This membrane is composed of fatty acids, preferably with a high percentage of Omega-3s. Unfortunately, the modern American diet has highly skewed the proportion of Omega-3s consumed in relation to other essential, non-essential, and even dangerous types of fatty acids. In other words, we eat way too much of what we don't need, way way too little of what we do.

Omega-3s are also used to create anti-inflammatory prostaglandin hormones. If one neglects to eat enough of the right fats, hormonal imbalances can occur. Most of the fatty acids we consume are actually used in the manufacture of inflammatory prostaglandins. Omega-3s, on the other hand, are used to create anti-inflammatory hormones. Without the proper balance, the circulatory system is at constant war with itself, like an allergic reaction within the body. Many researchers think that prostaglandin imbalance (and hence Omega-3 deficiency) is what allows arteries to become "hardened" in the first place. The arterial plaque gets stuck in the scar tissue that forms as a result of the constant inflammation, whereas healthy arteries are very smooth and do not have the inner "traction" for fat to actually accumulate.

So what's this about them being used to treat depression? Well, it turns out that certain Omega-3s (particularily DHA, Docosahexaenoic Acid) may play important roles in brain function. Studies have shown that they may alleviate symptoms of schizophrenia, and can lower aggression and depression in some people. Researchers have also demonstrated that there is a correlation between the ratio of Omega-6 and Omega-3 fatty acids in one's diet and their likelihood to suffer from depression and heart disease.

The problem is that we tend to primarily eat Omega-6 sources, and the same goes for our livestock. The resulting imbalance causes a positive feedback loop where the little Omega-3 that is consumed is never metabolized entirely. Because Omega-6 and Omega-3 fats compete for the same enzymes, an imbalanced ratio is skewed even further.

If you choose to buy flax seed oil, never buy it from a store that doesn't keep it refrigerated. Make sure it tastes nutty, but not bitter. Rancid oil is bad for you. The same goes for olive oil, which contains an almost inconsequential amount of Omega-3. The reason olive oil is good for you is because it is mostly comprised of oleic acid, a very stable, monounsaturated fatty acid that is not destroyed easily during cooking. Omega-3-rich oils should never be used for cooking, as they are far more likely to deform into unhealthy fats. Some people advocate the use of canola oil to increase Omega-3 consumption, but canola oil is usually highly refined at over 400°F to remove the natural stink of the seeds. This destroys most of the Omega-3 content, and the high temperatures actually hydrogenate a small percentage (around 4%) of the oil through hot chemical reactions. This is the reason that some European countries restrict trans fat percentages to 5% or lower; any heat-refined oil inevitably will contain a small percentage of artificial crap. This is bad, but not as bad as the deliberate hydrogenation process that converts up to 50% of soybean oil into trans fat.

Additional note: MissCreant is right, Omega-3s do wonders for pets with dandruff or shedding problems. As a matter of fact, most "pet supplements" designed to alleviate this problem consist of Omega-6 and Omega-3 fatty acid sources. Usually there's a large proportion of soybean oil, which has very little Omega-3. I prefer to give my cat pure flax oil, which has an almost immediate impact on his chronic dandruff problems. If I don't give him flax for a week, his dandruff is so bad that I can brush him indefinitely without getting rid of it. It's all over his back. Two days after a dose of flax, and it's almost entirely gone.

Why is this? Well, skin and hair cells are covered with bi-lipid membranes just like any other cell. Most of your cells are internal, and are surrounded by liquid at all times. The same can't be said for your hair and skin, which face the ravages of exposure to the air and sun. Omega-3s keep your cell membranes flexible, alive, and well. If you have chronic "night itching," try some flax oil. I used to have "ashy" itchy skin myself, especially at night, and now it's a rare occurrence that serves to remind me that I haven't been taking my flax oil.