Dry Eye Institute

Are your Omegas ok?

Are your Omegas ok?

We live in a society that places huge emphasis on dietary supplements and ensuring all of our dietary needs are constantly being met. Omegas are arguably one of the most discussed and well researched supplements on the market. So, what exactly are these omegas? And what is their purpose and benefit in dry eye disease?

For the science lovers among us; Omegas are naturally unsaturated fats containing one or more double bonds. For the less science oriented, omegas 3 and 6 are essential fats, meaning our body can not make them and must be obtained via diet or supplements. Omegas 9’s however are not considered essential as our body is able to produce these.  

There are three main types of Omega 3 fats: Eicosapentaenoic acid (EPA) and Docosahexaenoic  (DHA) acid found in fatty fish such as salmon, mackerel, sardines, trout and tuna.  Alpha-Linolenic acid is a plant based omega 3, found in foods such as walnuts, chia seeds, and flax seeds. However, because ALA has to be broken down in the body and only then converted to EPA and DHA, much larger amounts of ALA are required to achieve the same therapeutic benefits.  The large hype around Omega 3 fats is their proven importance in brain and cell metabolism, human growth and function and most importantly their anti-inflammatory effects.

Unlike omega 3 fats, omega 6 fats tend to be very high in our modern diets due to our lifestyles of convenience. A diet containing vegetable oils such as canola, safflower, sesame, peanut and soy is generally high in this class of omegas. While omega 6 fats are essential for skin, hair, metabolism and reproduction, it is important that we limit our intake of these due to their pro-inflammatory nature. The balance between omega 3 and omega 6 is vital in the control of inflammatory conditions and autoimmune diseases (1)

The third type of omega is the Omega 9 fats. These have been positively implicated in helping lower cholesterol levels (2) and are not required in the diet as our body is able to produce these (non essential).

This ratio of omega 3 to omega 6 intake is equally as important when it comes to Dry eye disease. Of the omega 3 fats EPA and DHA are the most preferred and most publicised due to their anti inflammatory effects (3). These two omega 3 fats have been consistently linked with an improvement in tear break up time, oil secretion and patient symptoms in sufferers of dry eye.  

The Australian Heart Foundation recommends 2-3 servings of oily fish a week as part of a healthy diet. This should provide 250-500mg of marine sourced omega per day. Studies  show that  individuals with a high fish intake, particularly fish with high levels of EPA and DHA,  have consistently been linked to lower rates of heart disease  (4) .  It follows that doctors will recommend omega 3 in both diet and supplement form for general patient health. Individuals with blood clotting disorders and seafood allergy sufferers should consult with their doctor regarding their omega 3 intake. However,  authors of a 2014 review suggest that omega-3s do not affect the risk of clinically significant bleeding (5)

Now the above advice is great if you eat fish…but what if it isn’t high on your list and what are the clinically therapeutic recommendations for omega 3 in supplement form? Walk down any supermarket or pharmacy aisle and you will easily see the many Omega 3 supplements available on the market. But with such a selection how do you know which are at the correct dose or a quality omega. Studies have shown that at least 1000mg of DHA and EPA is required for cardiovascular and mental health (6). These recommendations can go up to 4g a day in people suffering hypercholesterolemia and hypertriglyceridemia (7)

This is all great for systemic metabolic issues, but how much do we need for dry eye disease. A study published in 2016 found subjects receiving 4 oral softgels containing a total of 1680 mg of eicosapentaenoic acid/560 mg of docosahexaenoic acid showed a statistically significant improvement in tear osmolarity  (salt concentration of tears) , tear breakup time, inflammatory markers and patient symptoms (8). The supplement dose in this particular study equates to roughly 37 cans of tuna a week!   With respect to Dry eye disease 2000mg a day (combined EPA and DHA, ratio 3:1)) seems a proven effective dose to follow . However, ongoing research is now suggesting that the anti inflammatory effects of omega 3 may not actually kick in unless you have more than 2700mg of EPA and DHA (9).

For the uninformed population, knowing whether the omegas we are purchasing meet suggested guidelines can prove difficult. Often the front label of an omega supplement will state the total number of fish oils contained. It is important to note that this is not the actual total omega content and is always a good idea is to check that the amount of EPA and DHA on the back label is as close to the total omega on the front. Whether the omega is re-esterified form instead of alcohol ether form is also worth checking on the label. This is important as the re-esterified triglycerides are more easily absorbed by the body than the synthetic alcohol form and 124% better absorbed than omega rich foods (10).  What else makes one supplement preferable over another?  Typically a liquid or gelatin capsule is more readily absorbed by the body than a supplement with an enteric coating. An enteric coating is a coating which generally minimises the breakdown of a tablet in the stomach, but allowing breakdown once in the small intestine. This is favourable when a tablet can cause irritating side effect when broken down in the stomach. Aspirin is a good example of an enteric coated tablet (11) . It is also very important that omegas are stored out of the sunlight, and that they have been verified from an independent source to confirm free of heavy metals, pesticides and PCBS (12).  Most importantly is  your taking omega 3 supplementation consistently. Short term levels of DHA and EPA are not good biomarkers of Omega levels as it can take between 3-5 months for changes in red blood cells to occur (13).

The benefits of Omega 3 intake are widespread and essential and not only limited to more systemic metabolic conditions but play a huge role in Dry eye disease.  Using the above guidelines of form, serving, purity and coating recommendations will aid in finding a suitable and effective Omega 3 supplement.

Reference list:

1  Simopoulos AP. The importance of the ratio of omega-6/omega-3 essential fatty acids.Biomed Pharmacother. 2002 Oct;56(8):365-79.  

2  (Gene Bruno. Omega 9 fatty acids. Supplement Science. 2014 pg 37-38)

3 )(Fish oil: What the prescriber needs to know. Arthritis Research and Therapy 2006, 8:202, Vol 8, No 1, P2)

4 (Kris-Etherton P.M., Harris W.S., Appel L.J., Committee F.T.N. Fish consumption, fish oil, omega-3 fatty acids, and cardiovascular disease. Circulation. 2002;106:2747–2757)

5 Wachira JK, Larson MK, Harris WS. n-3 fatty acids affect haemostasis but do not increase the risk of bleeding: clinical observations and mechanistic insights. Br J Nutr 2014;111:1652-62

6 Etherton PM, Harris WS, Appel LJ. Omega-3 fatty acids and cardiovascular disease: New recommendations from the American Heart Association. Arterioscler Thromb Vasc Biol. 2003;23:151–152

7 (Miller M, Stone NJ, Ballantyne C, et al. Triglycerides and cardiovascular disease: A scientific statement from the American Heart Association. Circulation. 2011;123:2292–2333. 

8(Effect of Oral Re-esterified Omega-3 Nutritional Supplementation on Dry Eyes). Most evidence points towards a dosage of n0 less than 2000mg of DHA/EPA daily (Calder, Philip. Omega-3 polyunsatrated fatty acids and inflammatory processes: nutrtion or pharmacology? Br J Clin Pharmacol. 75:3, 645-662, p.655)

9(Omega-3 polyunsaturated fatty acids and the treatment of rheumatoid arthritis: a meta-analysis Arch Med Res. Lee YH1, Bae SCSong GG. 2012 Jul;43(5):356-62Epub 2012 Jul 24

10 Dyerberg J, et al. Bioavailability of marine n-3 fatty acid formulations. Prostaglandins Leukot Essent Fatty Acids. 2010 Sep).

11 ( Khan, Priya, PHD. To coat or not to coat. The case against enteric coating of fish oil softgels. Online reference.National institute of health/enteric coating. Online image 2, p.1)

12 Ashley, J.T.F. et al. Evaluating daily Exposure to polychlorinated Biphenyls and Polybrominated Dephenyl Ethers in fish oil supplememts: Food additives and contaminants: Part A 27:8, 1177-1185;

13 M.B. Katan, J.P. et al. Kinetics of the incorporation of dietary fatty acids into serum cholesteryl esters, erythrocyte membranes, and adipose tissue: an 18-month controlled study. J Lipid Res, 38 (1997), pp. 2012-2022

 

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