Positive Impact of Omega-3 DHA

Omega-3, DHA (docosahexaenoic acid) in particular, has a key part in the development and maintenance of the eyes – from the stages of early foetal development, infancy, growing children and continuing way into later in life. Plus, it plays a very important protective role as our eyes suffer in our modern environments.

The eye is a delicate organ that is particularly susceptible to damage. The retina, cornea, conjunctiva, eyelids, and tear film are essential for clear vision. As the structure of the eye is highly reliant on Omega-3 DHA, maintaining our DHA levels in the blood is crucial to protecting the eyes and preventing impairment, especially as we age.

This vital essential fatty acid is known to assist eye health by resolving inflammation, reducing effects of oxidative damage and increasing the activity of the mitochondria (powerhouses of the cells) in the retina. While maintaining the structural and functional integrity of the eye’s photoreceptors, DHA also helps to keep cells healthy and inhibit unwanted cell and tumour growth in the eye.

Dry Eye

Our eyes need a healthy coating of tears. Without this lubrication, our eyes become red, scratchy and irritable and can lead to a condition called Dry Eye Disease.

Dry Eye is one of the most common reasons for patients to seek ophthalmic care [4] and can impose a significant burden on quality of life. Along with natural irritants such as pollen, wind and bright sunlight, our modern environment does not do our eyes any favours. Pollution, tobacco smoke, air conditioning, long-distance driving and spending time in front of computer screens can put undesirable strain on our eyes. Even cold or allergy medicines can lead to dry eye. It is also common for women to develop dry eye during menopause, due to hormonal changes.

While artificial tears and ointments are the most common treatments for dry eye, many have found relief from consuming Omega-3 fatty acids. By improving function in the eye’s meibomian glands, which produce the oily part of tears, Omega-3s have shown to be beneficial in easing dry eye symptoms.

A study of 32,000 women found that those who consumed the most Omega-3 fats from fish had a 17% lower risk of dry eye compared with women who ate little or no seafood determined that that eating a diet rich in Omega-3 fats may help lower the risk of dry eye.

However, a 2018 study of more than 500 people found that capsules containing fish oil did not improve dry eye symptoms.

But there is good reason for that. More on why later.

Blue Light Damage

As a result of evolving technology, more and more blue light has been introduced into our homes and work environments. Our reliance on devices with LED-lit screens has further increased our exposure to blue light and the health impact it may have on our lives.

The negative influence blue light can have on our circadian rhythms, including a direct link to sleep disturbances, is well known. Numerous studies have also identified damaging effects of blue light, either short-term or chronic, on the retina of our eyes, our primary light sensor.

Having sufficient amounts of DHA in the cell membranes of the light receptors helps to regulate the production of the potent antioxidants that reduce the potential for damage. (9)

Whilst children and young people whose eyes do not fully filter blue light may be particularly sensitive, older eyes are more susceptible to damage. Long-term exposure to blue light has been identified as a contributing factor to the oxidative damage to the most sensitive area of the retina, the macula, in age-related macular degeneration (AMD) alongside low grade inflammation over many years.

Macular Degeneration

Age-Related Macular Degeneration (AMD) is the fourth leading cause of blindness worldwide. It is the result of damage to the macula, the central region of the retina, making it hard to read, recognise faces and carry out many everyday tasks.

Because DHA is the major structural and most important fatty acid of the retina (making up around 20% of its weight), it is not surprising that studies have shown a correlation between low Omega-3 intake and increased risk of AMD [5,6]

The antioxidative and antiangiogenic properties of Omega-3 DHA assist in reducing growth of abnormal blood vessels that occur in AMD and other retinal diseases.

To maintain eye health, the retina requires continuous renewal and a constant supply of Omega-3 fatty acids. Diets rich in DHA therefore, may greatly improve retinal function, even where damage has already occurred.

Building and maintaining a high level of DHA in the blood appears to provide a level of protection after the first signs of AMD appear [7], and very high dose Omega-3 could have some therapeutic benefit in partially restoring vision [8].

Glaucoma

Glaucoma is the leading cause of irreversible vision loss worldwide, and multiple risk factors influence its progression, including age, increased intraocular pressure (IOP), low-grade inflammation, oxidative stress, and ocular blood flow deficits. Maintaining high levels of DHA in our bodies may be beneficial for glaucoma patients as they act to decrease intraocular pressure, increase optic blood flow, and improve optic neuroprotective function, reducing the risk of glaucoma [3].

Interestingly, glaucoma patients have been shown to have lower Omega-3 fatty acid blood levels, especially DHA in their systems.

Dr Nguyen, Head of the Ocular Biomarker Laboratory in the Department of Optometry and Vision Sciences in the University of Melbourne stated ‘We found that increasing dietary consumption of Omega-3 fatty acids decreased intraocular pressure by about 25 to 30 per cent, a magnitude comparable to many topical glaucoma medications,’

‘We also found that this diet improved how well retinal ganglion cells function under normal conditions and even more so when they were under high intraocular pressure stress. Therefore Omega-3 appeared to have beneficial effect on two key aspects of glaucoma.’

Fish oil supplements not the answer

Fish oil supplements are a convenient source of Omega-3 and are often the first thing people reach for. Although research suggests that a diet rich in Omega-3 fatty acids may help reduce eye health problems, fish oil supplements were shown to be not very helpful in relieving dry eye symptoms and other ocular conditions.

The reason for that is most fish oils, due to their processing are in an unnatural synthetic ethyl ester form which is very different from the natural triglyceride form of Omega-3 found in unprocessed sea food and non-genetically engineered Algae Oil. Triglyceride forms are considered to have superior ability to be digested and absorbed by our bodies compared to ethyl ester forms [10].

Understanding these differences can affect the choices you make in selecting Omega-3 supplementation and can determine how much your overall health, as well as the health of your eyes will benefit.

• In whole fish, Omega-3 fatty acids are available in phospholipid and triglyceride forms = natural.
• In algae oil that is non-genetically engineered, Omega-3s are present in triglyceride form = natural.
• In processed fish oils found in supplements, as a result of the Omega-3s are in synthetic ethyl ester form resulting from the refining process that causes the triglycerides to convert to ethyl esters = unnatural. This further allows food chemists to unnaturally adjust the concentrations of DHA and EPA.

The absorption by the body of Omega-3’s in ethyl ester form is not as efficient as in the triglyceride form. Therefore, Algae Oil Omega-3 in the triglyceride form is the preferred choice for optical treatment.

Sources:

1. 10. Rand, A.L.; Asbell, P.A. Nutritional supplements for dry eye syndrome. Curr. Opin. Ophthalmol. 2011, 22, 279–282.
   
2. 11. SanGiovanni, J.P.; Chew, E.Y. The role of omega-3 long-chain polyunsaturated fatty acids in health and disease of the retina. Prog. Retin. Eye Res. 2005, 24, 87–138. [
   
3. Saccà, S., Cutolo, C., Ferrari, D., Corazza, P. & Traverso, C. The Eye, Oxidative Damage and Polyunsaturated Fatty Acids. Nutrients 10, 668 (2018).
   
4. 12. Stapleton, F.; Alves, M.; Bunya, V.Y.; Jalbert, I.; Lekhanont, K.; Malet, F.; Na, K.S.; Schaumberg, D.; Uchino, M.; Vehof, J.; et al. TFOS DEWS II Epidemiology Report. Ocul. Surf. 2017, 15, 334–365. [CrossRef]
5. Wu, J. et al. Dietary Intakes of Eicosapentaenoic Acid and Docosahexaenoic Acid and Risk of Age-Related Macular Degeneration. Ophthalmology 124, 634–643 (2017).
   
6. Merle, B. M. J. et al. Circulating omega-3 Fatty acids and neovascular age-related macular degeneration. Invest. Ophthalmol. Vis. Sci. 55, 2010–2019 (2014).
   
7. Souied, E. H. et al. Oral docosahexaenoic acid in the prevention of exudative age-related macular degeneration: the Nutritional AMD Treatment 2 study. Ophthalmology 120, 1619–1631 (2013).
   
8. Georgiou, T. & Prokopiou, E. The New Era of Omega-3 Fatty Acids Supplementation: Therapeutic Effects on Dry Age-Related Macular Degeneration. J. Stem Cells 10, 205–215 (2015).
   
9. Lafuente, M., Rodríguez González-Herrero, M. E., Romeo Villadóniga, S. & Domingo, J. C. Antioxidant Activity and Neuroprotective Role of Docosahexaenoic Acid (DHA) Supplementation in Eye Diseases That Can Lead to Blindness: A Narrative Review. Antioxidants 10, 386 (2021).
   
10. Dyerberg,J.;Madsen,P.;Moller,J.M.;Aardestrup,I.;Schmidt,E.B.Bioavailabilityofmarinen-3fattyacid formulations. Prostaglandins Leukot. Essent. Fat. Acids 2010, 83, 137–141.