The Skinny on Fatty Acids
Today, I’d like to discuss the second topic in our ‘Essentials’ series–Essential Fatty Acids.
You’ve probably heard about essential fatty acids.
And you’re undoubtedly familiar with the omega-3s and omega-6s.
But you might be a bit vague about what exactly they are–and how they can affect your health.
But like so many issues regarding diet today–there is a lot of confusion and controversy around essential fatty acids. And just like the essential amino acids we discussed last week, a lot of that debate swirls around what is the best diet source (fish or plants) to get your omega-3s.
But before we can take on those questions, let’s first examine what a fatty acid is…
What Are Fatty Acids?
A fatty acid is one of the building blocks of body fat. It is also one of the building blocks of the linings of cells and of some of the body’s hormones (called eicosanoids).
Fatty acids are crucial for good health; the body needs fatty acids in order to build and repair cell membranes, transport and oxidize cholesterol and make hormones related to immune functions.
Fatty acids get their name for scientific reasons; they are chains of carbons with hydrogens with an ‘acid’ group at one end of the molecule. They belong to one of three groups: saturated, monounsaturated or polyunsaturated.
And What About Essential Fatty Acids?
Unlike nonessential fatty acids (which we can synthesize or manufacture in our bodies), essential fatty acids must be obtained through dietary sources.
Specifically the two essential fatty acids that cannot be manufactured by the body are omega-3 and omega-6 fatty acids. The most common of the omega-3 and omega-6 fatty acids consumed by humans are alpha linolenic acid (ALA) and linoleic acid (LA), respectively.
It is important to note that essential fatty acids are polyunsaturated fatty acids or PUFAs (normally sourced from nuts and seeds). Monounsaturated fatty acids or MUFAs (typically sourced from foods like avocados and olives) are considered nonessential fatty acids.
The Truth About the Omegas
Linoleic acid is found in cell membranes and used to synthesize arachidonic acid (AA), which can be transformed into metabolites that promote inflammation and growth (during and after physical activity). It is abundant in nuts and fatty seeds (hemp, poppy, sesame, pumpkin, sunflower, flax) and in the oils derived from them. Most diets provide the proper amount of this omega-6 fatty acid and, therefore, daily requirements are easily met.
Alpha linolenic acid (ALA) is mainly found in flaxseeds, chia seeds and walnuts, but smaller amounts are present in other nuts, seeds, soybeans and green leafy vegetables. Contrary to omega-6 fatty acids, adequate intake (1.6 grams per day) can only be met if you incorporate omega-3-rich foods to your diet on a daily basis.
Getting the Balance Right
One of the most important things to remember about essential fatty acids is that the body needs them in the proper ratios for good health. Too much omega-6 in the diet can actually inhibit omega-3 as they compete with each other in the body. The recommended ratio of omega-6:omega-3 is between 1:1 and 4:1.
Unfortunately, most Americans don’t get the benefits of omega-3s due to the ratio imbalance in their diets, which often fall far out of the recommended range–between 10:1 and 25:1.
Not surprisingly, the reason for this imbalance is an over-consumption of oils and highly processed, nutritionally stripped foods.
Most healthcare professionals refer to the ratio imbalance as a “relative deficiency” of omega-3 and it’s believed that this type of deficiency causes a host of disorders, including liver and kidney abnormalities, and decreased immune function.
So What’s the Essential Fatty Debate REALLY About?
There is great debate when it comes to the subject of essential fatty acids, especially omega-3s. The controversy centers around two topics:
1) What is the best source to get your omega-3s (fish or plants)?
2) Are short-chain and long-chain omega-3 fatty acids equivalent?
Let’s first talk about the best place to source your omega-3s. Is it from consuming fish or fish oils? Or is it better to source them from plant foods?
It Might Just Be a ‘Fish Tale’
You’ve probably heard all about omega-3 and consumption of fish or fish oil capsules. While it’s true that you can obtain omega-3 from these sources, you also get what you might not want, including methylmercury and chemical residues concentrated in the fish flesh and fat through their diet and surrounding water.
Fish ‘toxic’ levels aside, it is also questionable whether or not fish-derived omega-3 does indeed promote health, especially when considering the high intake of omega-6 in the American diet. Recent clinical trials revealed that eating oily fish or taking fish oil capsules is not associated with lower risk of all-cause mortality, cardiac death, sudden death, myocardial infarction or stroke.
“The Eskimo Fish Tale” might be at the bottom of the fish oil myth. For a time, it was believed that Eskimos suffered from less heart disease and stroke due to their fish-rich diet. However as far back as the 1930s, this myth has been shattered – not just once, but over and over again.
In fact, the prevalence of coronary artery disease is just as high among Eskimos as non-Eskimo populations and their mortality rate is double that of the general population. Greenland Eskimos’ life expectancy is about 10 years shorter than that of the Danish population, and they suffer “excessive mortality” from cerebrovascular strokes.
The Power of Plants…Once Again
Plants are not only a good source of omega-3s; they come in ‘packages’ of balanced nutrition. Antioxidants, phytochemicals, fiber and vitamins and minerals are all present in whole plant foods – but not in fish or their oil derivatives.
The Fabulous Flaxseed
If you want the highest (and easiest) source of omega-3 in your diet, we must return to the mighty flaxseed (followed by the chia seed), which we recently described in detail in our Magic Seeds article. Not just because they contain higher levels of omega-3 than any other plant food, but because they also boast a higher ratio of omega-3 to omega-6 fatty acids.
A single tablespoon of ground flaxseed will give you a full daily requirement of ALA i.e. the short-chain omega-3 essential fatty acid that will then be converted by your body into the long-chain omega-3 DHA (more on that in the section below).
But keep in mind that you have to grind the flaxseeds and always store the ‘flax meal’ in the refrigerator or freezer to protect it from oxidation. Then simply add ground flaxseeds to your daily menu – e.g. cereals, smoothies, and salads.
One last important note. To get your omega-3s (and to keep a healthful ratio between omega-6 and omega-3), you should skip the oils, including flaxseed oil, and be mindful of your consumption of seeds other than flaxseeds and chia seeds and nuts other than walnuts. That is because most seeds and nuts (and their oils) will be a lot higher in omega-6 than omega-3 fatty acids.
In the end, one of the best ways to maintain a healthful omega-6 to omega-3 ratio is to follow a low fat whole food (plant-based) diet.
The Long & Short of It
The second controversy swirling around essential fatty acids centers on their ‘chain size’ and the body’s ability to convert short-chain into long-chain omega-3 fatty acids.
Without going into a detailed biochemistry lesson, fatty acid chains differ in length and range from short to very long. Short-chain fatty acids have fewer than six carbons, medium-chain fatty acids have 6-12 and long-chain fatty acids will have 13-21 carbons.
Plant foods mainly provide short-chain omega-3 fatty acids, while animal foods, such as fish, are a natural source of long-chain omega-3s.
Our bodies have a very limited ability to convert these short-chain omega-3 fatty acids (e.g. ALA) into the longer chain omega-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
However, the conversion rate seems to be higher in women and in those following a plant-based diet. This has been corroborated by a recent study of non-fish meat eaters, fish eaters, vegetarians and vegans, which suggested that vegans convert ALA more efficiently than non-vegans. In fact, vegans had higher DHA levels than all three groups!
Research done to assess the effects of omega-3s on the risk of cardiovascular disease has primarily focused on the long-chain fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). And for a while, it has been perceived that long-chain omega-3s are more health promoting than short-chain omega-3 (ALA). Current evidence suggests otherwise; ALA and EPA/DHA show comparable cardiovascular disease benefits, which further makes the issue of conversion rate non relevant.
So in the end…the ‘skinny’ on essential fatty acids is that the best way to get them (and to keep a healthful ratio between omega-3 and omega-6) is to stick to a low fat, whole food, plant-based diet.
So grab the (ground) flaxseed and those green leafy vegetables to make sure your body gets all the essentials from plants…once again!