When you think about fat (and who doesn’t these days?), you likely think about "good" fats and "bad" fats, or saturated fat and unsaturated fat. And that’s fine. Those of you who have an interest in nutrition might like to know a little more, however, about good fats, beyond what’s generally taught to the average consumer. So, if that’s the case, read on!
What Are Essential Fatty Acids?
If you ever took a nutrition course in school or have done some reading about nutrition, you’ve likely learned that protein is comprised of amino acids, which are often called protein’s “building blocks.” Some amino acids are essential, and others are not.
Well, as with protein, fat can be broken down into building blocks, too. These are called “essential fatty acids,” or EFA’s for short. EFA’s are polyunsaturated fats, otherwise known as “good fats.”
Essential fatty acids were “discovered,” as the story goes, back in 1929 (eight years after insulin was discovered, by the way) when a husband-and-wife research team observed that the animals in their lab had dry, scaly skin as well as damage to their internal organs (and eventually death) as a result of fatty acid deficiency. Over time, more research led scientists and nutritionists to conclude that certain types of fats are essential to the body; the body can’t make them, and without them, we’d die.
It might help to think of EFA’s almost like vitamins and minerals in that we need these nutrients for health and for survival.
Which Fatty Acids Are “Essential”?
There are two types of EFA’s: omega-3 fatty acids and omega-6 fatty acids. Both of these fatty acids are polyunsaturated, which means, for you chemists out there, that there is more than one cis double bond between the carbon atoms. These double bonds are located in different places between the omega-3 and omega-6 fatty acids. Why are these two types of fatty acids essential? Well, the body can actually make saturated fatty acids (a bad kind) and even some monounsaturated fatty acids (a good kind), but we lack the enzymes needed to insert those double bonds in the right places of these polyunsaturated fats. So because of this missing enzyme, omega-3 and omega-6 fatty acids must be taken in through the diet.
Which Fatty Acids Are Omega-3s and Which Are Omega-6s?
Think of omega-3 and omega-6 fatty acids as two main types, or classes, of EFA’s. Each class contains different EFA’s. You’ll likely recognize some of these.
Omega-3 fatty acids:
- Alpha-linolenic acid (ALA)
- Eicosapentanoic acid (EPA)
- Docosahexanoic acid (DHA)
Omega-6 fatty acids:
- Gamma linolenic acid (GLA)
- Linoleic acid (LA)
- Arachidonic acid (AA)
Omega-3 Fatty Acids Are Better Than Omega-6 Fatty Acids, Right?
Not necessarily. Both classes, or types of these fatty acids are essential, so we need all of them. However, there’s a correct balance, or ratio, of these two types of fatty acids. Unfortunately, the typical Western diet is way off-kilter.
Our Paleolithic ancestors had it right: They ate a diet that was not only much lower in saturated fat than ours is now, but also a diet that was about equal in omega-6’s and omega-3’s; in other words, the ratio was 1:1. Our diet today is more like 15 omega-6’s to 1 omega-3, or 15:1 to 17:1. We eat much less omega-3 fatty acid than we should, in part, because we don’t eat a whole lot of fish, and grains fed to animals are rich in omega-6 fatty acids, which means that meat contains more omega-6’s as well. Even vegetables, eggs, and farm-raised fish contain a higher proportion of omega-6 fatty acids. Some researchers think that we need to aim for a range from 2:1 to 5:1.
Why Does It Matter If We Eat More Omega-6’s Than Omega-3’s?
Omega-3 fatty acids are essentially anti-inflammatory, which means that they may help prevent a whole host of diseases, including heart disease, rheumatoid arthritis, asthma, Type 2 diabetes, and high blood pressure, to name a few. By eating more omega-6’s, scientists believe we’ve basically set ourselves up to develop more of these inflammatory diseases.
Bottom line: We need to change our “ratio” of omega-6’s to omega-3’s back to something a little more reasonable and a lot healthier.
More next week!