Life Extension Magazine®

Issue: Sep 2019

Improve Visual Acuity

Ingestion of plant carotenoids can lower risk of advanced macular degeneration by 41%. The addition of the spice saffron improves visual acuity as measured on a standard eye chart.

By Michael Downey

Macular degeneration is the leading cause of irreversible vision loss in older adults.1

It happens when the macula loses structural density. The result is blinding damage to the light-sensing retina of the eye.

Primary culprits like smoking and exposure to ultraviolet sunrays can be controlled.2-4 But the single, largest factor in its development is aging.5

Specific plant carotenoids have been shown to protect the macula from UV-light damage and oxidation.6-10

Individuals with the highest levels of the carotenoids lutein and zeaxanthin show a striking 41% lower risk of advanced age-related macular degeneration.11

A corroborating study found that saffron improved visual function in macular degeneration patients within three months. This visual enhancement occurred even among those who were already using lutein and zeaxanthin.11

Putting the brakes on macular degeneration and improved vision have been demonstrated in response to several plant-derived nutrients.11-16

Human Eye Anatomy and Macular Degeneration

Lutein and Zeaxanthin

Two of the best-known nutrients that protect against age-related vision loss are lutein and zeaxanthin.11 They’re found in high concentrations in several parts of the eye, including the lens, retina, and macula.17,18

These yellow carotenoids absorb higher-energy (blue and ultraviolet) light, preventing it from damaging retinal tissues. Lutein and zeaxanthin also scavenge free radicals and reduce their damaging impact on retinal cells.17-20

Several clinical trials have demonstrated their effectiveness. One recent study found a reduced risk of end-stage macular degeneration, which often causes blindness, with moderate consumption of eggs — a naturally rich source of lutein and zeaxanthin.21

Other studies of adults with age-related macular degeneration demonstrated that taking 10 to 12 mg of lutein daily raises the density of protective pigmented cells in the retina by up to 175%, compared with patients taking a placebo.12,13 Increased macular density enhances the ability to protect against eye-damaging ultraviolet and blue light.

In patients with early age-related macular degeneration, 48 weeks of supplementation with either lutein alone or lutein combined with zeaxanthin produced significant increases in electroretinogram signals. This is a measure of the power of light-sensitive cells to produce electrical impulses after stimulation by light.14

A series of large, clinical trials demonstrates that lutein and/or zeaxanthin supplementation can improve retinal function, increase the ability to see contrasting colors and shapes, and improve visual acuity (the sharpness of vision at a distance).9,11,13,14,22-24

One study that lasted over 20 years included more than 102,000 people aged 50 and older. It adjusted for factors like cigarette smoking and eating patterns.

After assessing blood levels of carotenoids, scientists found that those with the highest intake of lutein and zeaxanthin had a remarkable 41% lower risk of progressing to advanced macular degeneration. High intake of lutein and zeaxanthin even protected former smokers, who tend to have a much higher incidence of macular degeneration.11

Meso-Zeaxanthin

Woman getting eyes checked

The damaging effects of UV light are well known. But chronic exposure to blue light, the kind given off by TVs, smart phones, tablets, and computers, is also associated with increased risk of macular degeneration.25-27

Replenishing the pigments in the eye’s protective layer can quench much of the photochemical damage done by this light. In fact, research shows that progression of macular degeneration can be slowed by regular supplementation with lutein, zeaxanthin, and a third pigment, meso-zeaxanthin.28

Meso-zeaxanthin is a carotenoid needed to maintain the density of pigments in the macula. When young people consume lutein in their diet, it readily converts to meso-zeaxanthin.29

The importance of meso-zeaxanthin is reflected in the composition of macular pigments:

  • Lutein 50%
  • Zeaxanthin 25%
  • Meso-zeaxanthin 25%

People with macular degeneration have 30% less meso-zeaxanthin in their macula compared to those with good eye health.30

When taken as a supplement, meso-zeaxanthin is absorbed into the bloodstream and increases macular pigment levels.8

What you need to know

  • Age-related macular degeneration is the leading cause of vision loss in older adults, and it has no cure.
  • Certain carotenoids protect the macula from harmful UV-light damage and oxidation.
  • Lutein, zeaxanthin, meso-zeaxanthin, astaxanthin, saffron, and alpha-carotene have been identified as key nutrients that can protect the eyes and slow the progression of age-related macular degeneration.
  • Cyanidin-3-glucoside enhances night vision, that can be a problem also affecting those with age-related macular degeneration.

Astaxanthin

A reddish carotenoid that can be derived from marine algae, astaxanthin helps protect retinal cells from being damaged by oxidative and physical stress.31-33

In experimental studies astaxanthin prevented the vision-damaging effects of wet macular degeneration that occurs when blood vessels leak fluid into the retina. It can also help prevent cell damage related to increased pressure in the eye, a cause of glaucoma.32,34

The benefits of astaxanthin, particularly for diabetics, could be substantial. Among people who have had diabetes for over 10 years, 80% suffer from diabetic retinopathy, that occurs when high levels of blood sugar cause progressive damage to the retina. Rodent studies have demonstrated that astaxanthin prevents early death of nerve cells in the retina, resulting from excess blood sugar.31

Two human studies demonstrated that the combination of astaxanthin, lutein, and zeaxanthin significantly improved visual clarity in patients, compared with those who were untreated.35,36

Saffron

Woman driving at night

A study published in 2019 found that saffron, a culinary spice derived from the crocus flower, enhances visual function in patients with mild to moderate age-related macular degeneration, including those already supplementing with lutein and zeaxanthin.37

In this study, individuals took 20 mg of saffron or a placebo daily for three months. Subjects who weren’t taking other supplements improved on a standard vision-measuring eye chart by .69 letters, while those already taking lutein or zeaxanthin improved by .73 letters.37

This report validates earlier research demonstrating that, in people with early macular degeneration, saffron improves both visual acuity, and sensitivity of the retina to light.15,16,38

In one study, patients with early age-related macular degeneration took either 20 mg of saffron or a placebo daily. Subjects taking saffron showed stronger electrical responses to light, showing that saffron improved the light-sensing abilities of retinal cells.16

The same study found that saffron-supplemented subjects were able to read one entire additional line on the eye chart after three months, while placebo subjects did not improve. This means that someone whose visual acuity at a distance was 20/40 prior to supplementation, would be able to see with 20/30 vision afterward.16

To determine whether it could produce long-term effects, scientists gave 20 mg of saffron per day to patients with early macular degeneration over an average treatment period of 14 months. Retinal sensitivity remained improved for the entire period, and average visual acuity improved by an astounding two lines on the eye chart, showing that longer supplementation produced even greater improvement.15

Alpha-Carotene

Woman smiling after eye exam

Alpha-carotene protects the pigmented cells of the retina from light-induced oxidative damage.

A large study was conducted on 63,443 women and 38,603 men, aged 50 and older. The results showed that people with the highest dietary intake of alpha-carotene had a 32% reduced risk for developing advanced age-related macular degeneration, compared with those with the lowest consumption.11

This yellow-orange carotenoid has even been shown to provide protection for smokers.

In a recent study, scientists evaluated the dietary intake of carotenoids in 1,414 men aged 65 and over and their incidence of age-related macular degeneration. Current smokers who ate the most foods containing alpha-carotene (like pumpkin and carrots) were found to have a significantly reduced risk of developing macular degeneration.39

Protect Against Night Blindness

Many individuals with age-related macular degeneration experience difficulties when performing activities at night and under low light, such as driving or reading at night.40

A flavonoid found in many berries,41,42 cyanidin-3-glucoside enhances the quality and function of rhodopsin, a light-sensitive protein found in the rod cells of the retina, and actually boosts the ability of rhodopsin to regenerate.41,43-45 Rod cells are the eye’s most sensitive cells, allowing us to see in very dim light. Loss of rod cells is associated with night blindness or reduced vision in low light.46

A study of healthy volunteers showed that a berry extract concentrate containing cyanidin-3-glucoside improved night vision, allowing aging individuals to see better in darkness after just 30 minutes.47

Summary

Macular degeneration is a major threat to aging individuals.

Several plant compounds have been shown to protect against many of the underlying causes of compromised vision.

Saffron has been shown to provide protection against early macular degeneration.15,16,38

Alpha-carotene can help protect against advanced macular degeneration.11

Supplementing with an array of these plant compounds including lutein, zeaxanthin, and meso-zeaxanthin provides complementary eyesight protection.

If you have any questions on the scientific content of this article, please call a Life Extension® Wellness Specialist at 1-866-864-3027.

References

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