image of omega-3 fish oil capsules

The omega-3 fatty acid DHA (docosahexaenoic) is found in high concentrations in the retina. Research has shown that it plays an important role in the integrity of retinal blood vessels and nerves to maintain ocular health. Omega-3 is also a  potent anti-inflammatory.

Omega-3 is one of many fatty acids which are essential building blocks of cell membranes of the brain and nervous system. There are three main omega-3 fatty acids:

  1. Alpha-linoleic acid (ALA)
  2. Eicosapentaenoic acid (EPA)
  3. Docosahexaenoic acid (DHA)

The omega-3 fatty acids have been studied extensively regarding their role in cardiovascular health and neurological development.  From these studies, researchers have noted  improvement in the blood vessel and neurological health.

How does omega-3 affect the eyes?

The 3 main topics that researchers have evaluated on the effect of omega-3 on the eyes are:

1. Age-related macular degeneration (AMD),

2. Diabetic retinopathy, and

3. Dry eye disease (DED.)

Does omega-3 help with AMD?

fundus photo of drusen in the macula
Mild AMD,drusen in the macular area

What we know about the omega-3 effect on blood vessels and it’s anti-inflammatory property suggests a possible protective role. 

The most cited research on AMD and nutritional supplementation is the Age-Related Eye Disease Study 2 (AREDS 2).

Omega-3 fatty acids were included in the study, but are not a part of the commercially available AREDS2 eye vitamin formula.  Why?  Because the researchers concluded that it had no effect in preventing the progression of AMD to advanced AMD.  What the study did not evaluate is omega-3 as either protecting against or preventing AMD.

A much smaller study, the Nutritional AMD Treatment 2 (NAT2) found similar results: No effect on reducing the rate of progression to advanced AMD or reducing significant visual loss.  It did however suggest a protective role.

The NAT2 found that those with higher blood levels of  EPA + DHA had a substantial and significantly lower risk of neovascular AMD.  Neovascular AMD can lead to the ‘wet’ form of macular degeneration. (Ref; article comparing  AREDS2 and NAT2 study)

Researchers agree that more studies need to be done to better understand the protective role of omega-3 fatty acids.

Learn about macular degeneration: The 7 Truths About AMD

Are the omega-3 fatty acids good for diabetic retinopathy?

diabetic retinopathy image of eye
Diabetic retinopathy

Studies have shown that those with Type 2 diabetes, who consume two servings of oily fish per week or take omega-3 supplements, have a ‘significantly decreased risk of developing sight-threatening diabetic retinopathy.’ (Ref: JAMA Network )

The cause of diabetic eye disease is chronic inflammation of the leaky blood vessels of the retina.  This inflammation begins a cascade of blood vessel alterations, fibrosis, free radical formation, and the release of vascular endothelial growth factor (VEGF).  This process is diabetic retinopathy, which results in neovascularization with bleeding,  retinal cell death, and vision loss.

The benefits of omega-3 fatty acids for the prevention of cardiovascular disease have been studied.  This ‘good’ fat is known to be anti-inflammatory.  It also protects the diabetic retina by decreasing new blood vessel formation and has antioxidant activity.  Omega-3 fatty acids have the potential to decrease the complications of diabetic retinopathy.

Can omega-3 help with dry eyes?

Studies have shown improvement in dry eye symptoms for those who increase their omega-3 fatty acid intake.  They help reduce DED symptoms and signs by modulating ocular surface inflammation and improving tear-lipid profiles. 

The benefit of omega-3s for dry eyes is controversial.  Doctors have long recommended to their dry eye patients that they supplement omega-3 fatty acids to reduce inflammation and promote healthy eyelid glands that produce moisture.  It is thought to be most effective when used in conjunction with other treatments  like lubricating eye drops, warm compresses, and anti-inflammatory eye drops.

What are food sources for Omega-3 Fatty Acids?

image of salmon filets

DHA and EPA omega-3 fatty acids are found in fish oils (Ex: salmon, herring, sardines, trout, mackerel.)  ALA omega-3 is found in nuts, flaxseed, and vegetable oils.

Omega-3 is what is called unsaturated fat.  Unsaturated fats from vegetables and fish are liquid at room temperature.  (Saturated fats tend to be solid at room temperature and are usually found in animal fat and dairy products, like cheese and butter.)

For those with fish allergies or for those who are vegans, flaxseed and flax oil are a source of the ALA form of omega-3 and there are commercially available DHA sources derived from yeast and microalgae.

Which omega-3 is best for the eyes?

While there are many fatty acids, the most important dietary omega-3 fatty acids are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).

ALA is termed an “essential” nutrient meaning it must be ingested because we cannot make it in our bodies.  EPA and DHA can be formed from ALA.

There have been many studies on the benefits of omega-3 fatty acids for cardiovascular, brain, eye, and joint health. When trying to decide on their benefits, you may find that  studies are contradictory to one another.  Studies do differ on whether it is DHA and EPA supplements or if it is omega-3 fatty acids ingested by dietary fish and fish oils.

Nutritionists will say that eating oily fish is the best source.  If you choose to supplement, purchase supplements from a manufacturer who has done third-party testing for purity and consistency. 

How much omega-3 is recommended daily?

The USDA has not established a Recommended Daily Allowance for omega-3 fatty acids.  It is suggested a dietary intake of 2 to 3 servings of omega-3 rich fish per week (8 ounces, approx. 1000 mg omega-3 per serving. This varies depending on the type and quality of the fish.)

Studies of AMD and omega-3 are inconclusive as to daily dosages.  Researchers of cardiovascular disease and dry eye therapy recommend  1000 mg ( 1 gram) fish oil capsules per day as beneficial.  The dosage upper limit is 3000 mg/day.  Higher dosages may lead to toxicity.

Cod liver oil  is a source of omega-3 fatty acids, but is also high in Vitamin A and D at levels that could be toxic for some individuals.

Take fish oil capsules with food to offset the fishy after-taste.   Some find the fish oil bothers their stomach causing belching and heart-burn.  There are enteric-coated capsules that may reduce the unpleasant stomach upset.

Who should not take omega-3?

Those with allergies to fish should take plant-based omega-3 supplements: flaxseed, walnuts, and soybeans.

Those who are on blood thinners, like warfarin, Plavix, apixaban (Eliquis), and aspirin therapy, because DHA/EPA have a blood thinning effect.  Hemophiliacs should also be aware.

It is advised to consult with a physician before starting high-dose supplementation of omega-3 if you are hypotensive, on blood thinners, scheduled for surgery, or chemotherapy to ensure the powerful effects of omega-3 are not contraindicated. 

How long does it take for omega-3 to work for the eyes?

It may take 2 to 3 months for a noticeable effect.  

Fish, flaxseed, and omega-3 supplement capsules are ‘natural’ treatments.  Natural nutritional supplements take longer for benefits than a pharmaceutical therapies.  

How do I check my omega-3 levels?

image of OmegaQuant test packet

There is an at-home test kit produced by OmegaQuant. (Use coupon code I3URD3NZSK for 5% off at check out.)

You can purchase a test kit to get your DHA and EPA blood levels.  They have additional test kits for testing other omega fatty acids and trans fats.

The test requires a drop of blood as the test sample, which is mailed off to the OmegaOuant lab.  The lab generates a report on your omega profile.

This is a good option to determine if your diet is sufficient in omega-3s, or if you have a deficiency.

This company also has test kits for Vitamin D, B12, Prenatal DHA, HbA1C, and even your pet’s omega-3 index.

In the end..

Omega-3 fatty acids are the ‘good’ fats, essential for their anti-inflammatory activity and their role as components of cell membrane structure and function.  DHA is the predominant omega 3 concentrated in retinal cell membranes.  This suggests an important role for vision and nerve function.

More research is needed to fully understand the role of the omega-3 fatty acids  in preventing and/or protecting against the development of eye disease.

Learn more about ocular health: What is the Best Supplement to Preserve Eye and Brain Health?