Fish Oil for Vision

Fish oil supplies fundamental omega-3 fatty acids that help to nourish both eye health and vision performance.

Fish oil maintains one of the highest portions of healthy omega-3 fatty acids that are vital ingredients in our diet. It is consumed for many wellness benefits, and may support healthy eyesight by its ability to:

• Stabilize photoreceptors. Some of fish oil’s omega-3’s are crucial parts of the photoreceptor cell membrane and may aid in retinal regeneration.
• Maintain healthy retinal vasculature. The fatty acids in fish oil help to keep blood vessels flexible and healthy, potentially supporting microcirculation that nourishes the retina and macula.
• Enhance tear film stability. Taking fish oil has been shown to support hydrated, healthy eyes, and may assist with dry eye syndrome.

Overview

Omega-3 fatty acids form an essential component of our diet because the body does not naturally produce them, and much of our food intake is lacking in them. The good news is that fish oil can be drawn from cold-water fish like sardines, tuna, and salmon that consume microalgae containing profuse portions of omega-3 fatty acids, including docosahexanoic acid (DHA) and ecosapentaenoic acid (EPA). These fatty acids can also be found in a variety of other fish sources, like krill oil or calamari extract; and non-fish sources, like flaxseed oil and vegan supplements.

Fish oil’s active health-promoting ingredients — the healthy Omega-3 fats DHA and EPA — are highly regarded for general well-being. Such bio-activities as inflammation modulation, blood vessel flexibility promotion, and circulatory support are upshots of eating fish oil that benefit our heart, cardiovascular, neuronal, skeletal and immune systems in a variety of ways.

• As a nootropic and nerve-health nutrient, the omega-3 fatty acids that are so abundant in fish oil assist in the formation of neural cell membranes while maintaining membrane fluidity and proper function.

These bio-activities, which drive the development of infant brains both in the womb and throughout childhood, play a part in eye health as well.

The significance of DHA in eye health and vision performance is highlighted in stages of fetal development, during which DHA amasses in the brains and retinas of embryos. Such accumulation of the omega-3 fatty acid points to its seemingly critical impact on retinal maturation. In a particular study of Inuit infants, researchers identified that higher concentrations of DHA in the umbilical cord is associated with better visual, cognitive, and motor coordination.¹

Not only are omega-3 fatty acids plentiful in the retina – DHA is the principal fatty acid found in retinal rod outer segments (ROS)² – but they may farther be essential pieces in visual progression.³

Good Fats, Bad Fats

DHA appears to continue supporting suitable eye health even into adulthood, with the most noteworthy advantage tying in to age-related vision issues due to:

• Unsaturated “good” fats like DHA and other omega-3’s, which according to research, reduce the risk of acute macular degeneration (AMD).
• Saturated fats, commonly found in the omega-6’s of animal products, that have been associated with AMD risk.

Skipping out on DHA has been linked to an assortment of health complications, like AMD, especially when it comes to neurodegeneration of ocular neurons⁴, and retinitis pigmentosa⁵, for instance. Beyond this, DHA additionally seems to carry promise in regards to vision performance.

How Fish Oil May Help with Vision Performance

Optimizing photoreceptor cell membranes

Tissue DHA status affects retinal cell signaling mechanisms that are involved in phototransduction. Specifically, DHA may operate in signaling cascades to enhance the activation of membrane-bound retinal proteins, like M(II)-transducin⁶, and may also be involved in rhodopsin regeneration due to its role in transporting vital rhodopsin elements through interphotoreceptor retinal binding proteins.⁷

Increasing oxidative stress endurance in the retina

Oxidative stress, combined with the accumulation and aggregation of misfolded proteins in the retina, can eventually lead to the loss of photoreceptor cells and central vision. With doses of DHA, however, the oxidative response regulator NFE2/NRF2 is activated and may accordingly rescue cells from the cell cycle arrest induced by oxidative stress. Moreover, after applying DHA, human retinal cells appeared to accumulate intracellular protein aggregates integrated with SQSTM1/p62 (sequestosome 1) alongside a transient increase in autophagy, which in effect, mobilizes the cleansing of misfolded proteins.¹⁰

Assisting in the biosynthesis of photoreceptor cells

DHA is an essential constituent of the phospholipids that form the disk membranes of photoreceptor outer segments and synaptic terminals, which suggests its importance in the establishment of photoreceptor cells.¹¹ Conversely, drops in DHA levels in the retina may thus consequence in photoreceptor cell degeneration.

Maintaining structure and function of vascular retina

DHA and EPA suppress the expression of a number of angiogenic factors, such as VEGF, which may in turn minimize inflammation, excessive cell growth, and microangiopathy in order to stabilize ocular blood flow.¹² Diminishing the occurrence of negative effects in the retina may help keep the eye in first-rate condition.

Fish Oil Vision Performance Benefits & Uses

The ability to limit undesirable cases of dry eye and early AMD are practical long-term benefits of regularly consuming fish oil or its equivalent of omega-3 fatty acids.

Potential uses of fish oil in enhancing vision stem from its inherent and critical position as a member of the retina family. There is evidence supporting its potency in tear film stability, reducing oxidative stress and inflammation in the eye, and assisting in the cultivation of photoreceptor cells while optimizing function, all of which may help to improve vision performance.

It is further used in a collection of vision health stacks, usually combined with carotenoid antioxidants – where polyunsaturated fatty acids in fish oil may serve as a means of reducing the likelihood of AMD development (which may progress to blindness if left unchecked), while antioxidant carotenoids handle managing existing AMD.

Research

Animal Research

Research is heavily based on the necessary presence of fish oil fatty acids like DHA in photoreceptor cells and the positive effects that follow. Fish oil helps vision health through:

• Protecting against retinal light damage. Photorecepter damage in the retinas of rats that consumed dietary fish oil displayed a reduction in damage at the base of the ROS.¹³
• Facilitating in the formation of retinal cells. An examination of frog photoreceptor cells revealed that DHA is released from rod outer segments, when they are ready to be renewed, and then rapidly incorporated into retinal pigment epithelial cellular lipids, which suggests their immediate need in the configuration of retinal cells.¹⁴¹⁵
• Aiding photoreceptor cells. A steady reservoir of DHA is consistently sustained in the membrane of photoreceptor cells of frogs and mice to facilitate its rapid assembly when required.¹⁶

Human Research

In vivo human trials present somewhat of a mixed display of findings. Some research studies demonstrate encouraging results after taking fish oil, while others conclude that taking some of the active ingredients of fish oil under certain conditions may not actually have much of an impact:

Fish consumption (> 4 servings per week) may lower risk of AMD

Harvard Medical School researchers analyzed the food intakes of over 72,000 male and female nurses and doctors, aged 50 or older. Over the course of nearly a decade, the prospective study ascertained that those who ate more than four servings of DHA and EPA-rich fish per week had 35% less development of AMD than those who ate three or fewer servings per month.

• The research study determined that “a high intake of fish may reduce the risk of AMD.”¹⁷

Fish oil supplements containing DHA (350 mg) & EPA (650 mg) might not reduce risk of AMD progression

In this government approved multicenter, randomized, double-masked, placebo-controlled phase 3 study with a 2 × 2 factorial design, 4203 participants aged 50 to 85 years that were at risk for progression to advanced AMD were offered DHA (350 mg) & EPA (650 mg) supplements. In comparison to the development of AMD in people who took the placebo (31%; 493 eyes; 406 participants), a very slightly smaller number of those who took a combination of DHA & EPA along with the carotenoids lutein & zeaxanthin came out with AMD (30%; 472 eyes; 387 participants) over the course of 5 years.

• The research study determined that “addition of lutein + zeaxanthin, DHA + EPA, or both to the AREDS formulation in primary analyses did not further reduce risk of progression to advanced AMD.”¹⁸

Fish oil supplements containing DHA (12oo mg) might not resolve retinitis pigmentosa 

In this randomized, controlled, double-masked trial of 221 people with retinitis pigmentosa between the ages of 18 – 55 years were given DHA capsules at 1200 mg per day over a 4-year interval. There were no significant alterations observed in loss of visual sensitivity for people who took the supplementation when compared to those who did not.

• The research study determined that “docosahexaenoic acid supplementation over a 4-year interval did not, on average, slow the course of disease in patients with retinitis pigmentosa.”¹⁹

Fish oil supplements containing DHA (400 mg) may reduce rod functional loss but not affect vision performance

In this 4-year, prospective, randomized study, males with X-linked retinitis pigmentosa (XLRP) received DHA capsules at 400 mg per day. Full-field cone electroretinograms (ERG) displayed preservation of cone ERG function with decreased change in fundus appearance in those who took DHA, but visual acuity and visual fields, concurrent with the rate of cone ERG functional loss, was not significantly altered.

• The research study determined that “DHA supplementation was beneficial in reducing rod ERG functional loss…and preserving cone ERG function in patients,” although “neither visual acuity nor visual fields were changed.”²⁰

Fish (≥ 5 servings of tuna) may decrease the presence of dry eye syndrome in women

1546 women with dry eye syndrome (DES) between the ages of 45 – 84 years took either ≤ 1 serving, 2 to 4 servings, or ≥ 5 servings of tuna fish per week. Using logistic regression modeling, the researchers calculated that the odds ratio (OR) decreased in proportion with increased servings of tuna fish, such that a higher dietary intake of n-3 fatty acids, or omega-3, is associated with a decreased presence of DES in women.

• The research study determined that “increasing dietary intake of n-3 FA may reduce the risk of DES, an important and prevalent cause of ocular complaints.” ²¹

While a couple of studies indicate that fish oil may not directly rectify retinitis pigmentosa or prevent the risk of advanced AMD progression, these results do not necessarily negate the value of fish oil, but rather point out its potential minor limitations in states of already concerning health. The effectiveness of fish oil in relation to vision enhancement seems to be relevant for people looking to either preserve current healthy eye function or enhance vision performance.

Dosage for Vision Performance

Fish oil may be ingested in the form of:

• A serving of fish, 900 mg (tuna) – 3890 mg (atlantic salmon) of omega-3s, daily
• As a fish oil supplement, most commonly as a softgel, minimum of 1,000 mg of omega-3s daily

References