Omega Fatty Acid Supplementation, Not Limited to Fish Oil

Fatty acid (FA) supplements, particularly those containing omega-3 fatty acids, have become one of the top ingredient categories within the dietary supplement industry. Both omega-3 and omega-6 FAs are structural components of cell membranes, are sources of energy and are precursors to lipid mediators that play vital roles in immune and inflammatory responses; and the typical Western diet doesn’t provide the best balance of these nutrients on its own. But, the way these important fats work in the body involves complex metabolic pathways that should be at least minimally understood in order to know and understand the best way to supplement with them.

There are only two truly essential FAs, meaning that our bodies cannot make them. Our diet needs to include the omega-3 FA, alpha-linolenic acid (ALA) and the omega-6 FA, linoleic acid (LA). Green leafy vegetables, nuts, (particularly walnuts) and seeds such as flaxseed are good sources of ALA. LA is found in abundance in plant oils, including sunflower, safflower, corn and soybean oils. Adequate dietary intake of ALA and LA can then provide the initial building blocks for the body to make the longer-chain polyunsaturated fatty acids (PUFAs) that it needs to maintain optimal health and functioning. Ideally, the diet should contain a ratio of omega-6 to omega-3 of from 1:1 to 4:1, but unfortunately, the current Western diet contains a much higher proportion of LA, ranging from 15:1 to almost 30:1 by some estimates, due to our overconsumption of processed foods that are prepared with omega-6 oils. As a result, most of the current focus has been on our need for increasing omega-3 fatty acid intakes.

In the body, ALA metabolizes first to stearidonic acid (SDA), a longer chain FA that possesses many of the same attributes as eicosapentaenoic acid (EPA), mostly through its role as an anti-inflammatory.[1] Through a series of reactions, SDA ultimately metabolizes to EPA and docosahexaenoic acid (DHA), the two key omega-3s that have been researched for many health benefits. Likewise, LA metabolizes to gamma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA) and under many conditions on to arachidonic acid (AA). GLA and DGLA are linked to the production of anti-inflammatory substances and are beneficial in maintaining brain function, skeletal and reproductive health, and metabolism. They are also essential for stimulating skin and hair growth. On the other hand, AA is pro-inflammatory and plays a vital role in initiating the inflammatory process.

Under optimal conditions, consuming a diet that contains balanced amounts of foods containing both ALA and LA would result in enough of the end-products of their metabolism for our bodies to function as they should and maintain health. But, unfortunately, it is not that simple. The metabolic pathways of ALA and LA share several enzymes needed for the various intermediate reactions and are also influenced by the relative levels of longer chain fatty acids produced by the reactions occurring in the other pathway. For instance, adequate levels of EPA must be present for the conversion of the omega-6 FA, DGLA to anti-inflammatory prostaglandins. If there isn’t enough, the reaction will favor the production of the pro-inflammatory fatty acid, arachidonic acid.[2]

One of the main factors that influence the metabolic pathways of both essential fatty acids is the requirement of a rate-limiting enzyme called delta-6-desaturase (D6D) as well as the cofactors for the reaction, including magnesium, zinc and vitamin B6. These are necessary to facilitate the first reaction in both pathways. This reaction is slow and can be inhibited by multiple factors that affect many people, including medication, illness, aging and nutrient deficiencies. So, it is not uncommon for the metabolism of the essential fatty acids to stop at the very first step, which can have disastrous effects on human health. Without D6D and the cofactors needed to initiate the reaction, ALA cannot metabolize to SDA, and LA cannot metabolize to GLA, so the benefits of GLA, SDA, EPA and DHA are lost. Ultimately, these crucial omega fatty acids become conditionally essential as the body can no longer make them and they must be obtained through diet or supplementation. This has opened the door to selective supplementation.

The most widely recognized fatty acid supplement type is fish oil. Fish oil contains EPA and DHA, the endpoints of omega-3 fatty acid metabolism. EPA is recognized mostly for its anti-inflammatory attributes and benefits in reducing the risk of chronic diseases linked to inflammation, such as heart disease. DHA is integral to brain development and function as well as eye health. EPA and DHA are only found naturally in marine sources, including oily fish, krill and algae. The dietary sources (oily fish like salmon, mackerel and sardines) are also less likely to be a regular part of the Western diet, contributing to the potential for deficiency.

Because of the overabundance of LA in our diets, less attention has been given to the potential for omega-6 deficiencies due to deficiency of D6D. This is unfortunate because GLA/DGLA do play important roles in the body that can also be compromised. In addition, the overall balance in the omega-6 and omega-3 metabolic pathways due to the sharing of enzymes and cofactors that the body tries to maintain could be disrupted; so supplementing with just the end-products of the omega-3 fatty acid pathway may not always be the best option.

For some individuals who have low serum levels of EPA and DHA, due to inefficient conversion from ALA and/or no dietary intake through food sources, supplementation with these two omega-3s might be beneficial, and high-quality fish, krill or algal oil supplements with a ratio of EPA to DHA of around 2:1 are generally recommended. Also, pregnant women may want to consider DHA supplementation to help support neurological development.

For those who are not deficient in EPA or DHA, EPA/DHA supplementation alone may not be best and could be detrimental in high doses.[3] For persons who are deficient in the key enzyme (D6D) or one of the cofactors needed to begin the first reaction in the metabolic pathway of both ALA and LA, a different approach to supplementation may be preferable. In addition, some recognize a need for fatty acid supplementation, but do not wish to consume fish or take marine sourced supplements. As a result, additional options in fatty acid supplementation have arisen to meet these needs.

Flaxseed, hemp and chia seed oils have gained in popularity because they are vegetarian sources of the omega-3, ALA. They are marketed to offset the high levels of LA consumed by so many through diet. These can be beneficial to many, but only those who are not deficient in D6D or its cofactors. In addition, GLA supplements have experienced an increase in popularity in products marketed for general inflammation support, women’s needs related to hormonal fluctuations and for conditions that affect the skin.

But for many who desire a more balanced fatty acid option and general support to offset potential broader deficiencies, supplementing with a blend of fatty acids including ALA, LA, GLA, SDA and perhaps also DHA and EPA might provide the best choice, but would most likely necessitate supplementing with several different products. Another choice would be a plant source that contains not only ALA and LA, but also the next important fatty acids past the crucial enzyme-dependent step in both the omega-3 and omega-6 pathways. Ahiflower seed oil, derived from Buglossoides arvensis, a plant native to the British Isles, is not only a good source of both ALA and LA; it is an excellent source of GLA and is unique in its exceptionally high content of SDA.[4] Supplementation with this one ingredient helps ensure the necessary building blocks for the body to naturally complete the omega-3 and omega-6 pathways, and also reap the benefits derived from the intermediate fatty acids, GLA and SDA.[5]

It is becoming increasingly apparent that supplementation with omega fatty acids, just like many other important nutrients, is not a “one size fits all,” but instead can, and should be tailored to an individual’s own diet and lifestyle. Probably most, if not all of us need to consider some type of omega fatty acid supplementation because of the extensive role they play in maintaining overall health, beginning in every cell in our bodies. And now, more than ever, it is possible to select the right supplement to fit our individual needs and preferences.

 

Article Published by: Nutraceuticals Now

References: 

[1] Lipids (2017) 52:781-787

[2] Eur J Pharmacol (2016) 785:77-86

[3] Transl Psychiatry (2019) 9(1):303

[4] Mol Nutr Food Res (2013) 00:1-12

[5] Nutrients (2017) 9(3). pii:E261