We have all heard about omega 3 fatty acids and their health benefits, but not everyone understands what an omega 3 fatty acid is and why they are important for our health. I have found that understanding the rational behind a recommendation often improves compliance, so here is a brief explanation of common fatty acids, and why consuming a variety is so important.
Omega 3 fatty acids are required for normal metabolism and are an essential fatty acid, meaning we can not produce them on our own. The three main types of omega 3 fatty acids are ALA, EPA, and DHA. ALA is found in plant sources such as flax seeds and EPA and DHA are found largely in marine sources and pasture raised animals. Our bodies are capable of producing the longer chain omega 3 fatty acids (EPA and DHA) from ALA but the process is not very efficient (only about a 15% conversion rate), so a diet high in foods containing all three omega 3s (ALA, EPA, and DHA) are encouraged.
Omega 6 fatty acids, also called “n-6”, are polyunsaturated fatty acids with a double bond at the sixth carbon atom. They are essential for human health, but as with omega-3s, our bodies are unable to produce them. Due to the high consumption of vegetable oils, the typical American gets more than enough omega 6s. And it is this high intake of omega 6 and low intake of omega 3 that is a major contributing factor in the spread of inflammation and chronic disease.
Omega 9 fatty acids (oleic acid) are polyunsaturated fatty acids with a double bond at the ninth carbon. Unlike omega 3 and omega 6, our bodies produce omega 9 fatty acids, so we do not have to be as diligent about including them in our diets. As you can see in the chart provided, omega 9 fatty acids are quite common and are particularly high in olive oil.
While I state that there is no bad fat with the exception of trans fats, it is also important to note that ratio of different fats is very important to optimal health. A great deal of research has looked at the importance of our ratio of omega-3 to omega-6 fatty acids. It is thought that our ancestor’s dietary ratio of omega 6 to 3 was approximately 1/1. Current estimations are that a typical western diet has an omega 6 to 3 ratio closer to 15/1 or higher. Why such a change? If you look at the diagram below you will see commonly used fats in a typical western diet. As you can see, two major contributors to our calories are also very high in omega 6 fatty acids…CORN and SOY. Next time you stroll through the isles at the grocery store, randomly pick up a few products and read the ingredient list. Chance are you will find either corn or soy,or a product produced from them, listed. I am not saying that corn and soy can not be part of a healthful diet, but again, we go back to balance. Also, you must take into account that the majority of corn and soy produced in the United States is genetically modified.
You may all be asking…why does it matter...how does this impact my health? An optimal ratio of omega 6 to 3 fatty acids (around to 2:1) is believed to reduce inflammation, and inflammation is the driving force of chronic diseases. The research is plentiful, and shows a positive effect of an improved ratio on conditions such as asthma, arthritis, cancer and heart disease, just to name a few. A recent study published in the Journal of Experimental and Therapeutic Medicine did a meta-analysis (review of available research on a particular topic) and found that the majority of studies concluded a diet rich in omega 3s, and limited omega 6s, had a positive outcome on the reduction of risk of breast cancer (1). The optimal ratio varies with different chronic diseases, but the consistent finding is the closer the ratio is to 1:1 the more positive the outcome for chronic disease.
Looking at the chart provided above, if you compare canola oil to corn oil you can see that canola oil has an omega 6 to 3 ratio of 21/11 (approximately 2/1) and corn oil has a ratio of 57/1, and HUGE difference!! One thing to be aware of, is that a large majority of canola is genetically modified, so try to select a GMO free or organic option and choose cold processed, expeller pressed canola oil.
As mentioned before, fats found in whole foods are your best options, such as nuts, avocados, pastured meats, eggs, olives, etc. When you consume fats in their whole food forms, you increase the nutrient density of your diet and the fats are more stable and less likely to become oxidized. When you are using oils, select organic or non-gmo options and expeller pressed. Fats are an essential part of a healthy diet so make sure to consume a variety of healthy fats daily!
Sarah Burnett, MS, RDN, LD