Landmark Clinical Zeaxanthin Studies

Use of carotenoids in supplements is the fastest-growing category among dietary supplements due to their antioxidant properties. Emerging science is identifying the specific function of zeaxanthin in preventing certain diseases or disorders for which there is often no cure.

Various studies have found that typical intake of zeaxanthin is less than 0.5 milligrams a day. The adequate amount, however, for the body to reap the benefits of zeaxanthin is between 2 and 4 milligrams. The need to supplement daily dietary intake is even greater in adults over the age of 50, when carotenoid consumption is significantly lower. Research has also shown that women, smokers and overweight people are more at risk of developing AMD than other population groups.

Main clinical studies about the affects of zeaxanthin on eye health

Zeaxanthin & Age-Related Macular Degeneration:
Risk of age-related macular degeneration (AMD) was significantly higher in people with low concentrations of zeaxanthin in their blood. Lutein and Zeaxanthin Status and Risk of Age-Related Macular Degeneration Investigative Ophthalmology & Visual Science, June 2003, Vol. 44, No. 6

Zeaxanthin & Visual Performance Under Bright Light:
Supplementation with 2 mg of zeaxanthin and 10 mg of lutein resulted in an increase in the Macular Pigment that was then directly related to improvements in glare disability and photo stress recovery times.

Supplemented subjects could tolerate 58% more intense glaring light before losing their ability to detect a central target. They also had, on average, 14% faster recovery to photo stress. Macular Pigment and Visual Performance Under Glare Conditions. Optom Vis Sci 2008;85:82–88

Zeaxanthin & Cognitive Function:
It is well recognized that an increase in brain oxidative stress is one of the leading causes of cognitive impairment. High Zeaxanthin concentration in the blood was found to be highly correlated with better performance in a series of cognitive tests (the Digit Symbol Substitution, the Finger Taping Test, the Word Fluency Test and the Trail Making Test Part A). Plasma Carotenoid Levels and Cognitive Performance in an Elderly Population: Results of the EVA Study. Journal of Gerontology. 2007, Vol 62A, No.3, 308-316

Zeaxanthin, AMD & Cataracts:
A study involving over 2,500 participants found that people with high levels of zeaxanthin in their blood have 93% less risk of AMD and 75% less risk of developing a nuclear cataract.

Plasma Lutein, Zeaxanthin, and Other Carotenoids as Modifiable Risk Factors for Age-Related Maculopathy and Cataract: The POLA Study. Invest Ophthalmol VisSci. 2006;47:2329–2335.

Zeaxanthin & Cataracts:
A study involving close to 5,000 participants found high dietary zeaxanthin and lutein intake reduced the risk of developing a cortical cataract by 30 percent.

Dietary Carotenoids and Cataract in the Age-Related Eye Disease Study: ARVO Abstracts, 2006

Zeaxanthin & Diabetic Retinopathy:
Dietary carotenoids are significantly lower in diabetics. Zeaxanthin and lutein significantly inhibit the damage diabetes can cause to the retina.

Beneficial Effect of Zeaxanthin on Retinal Metabolic Abnormalities in Diabetic Rats. Invest Ophthalmol Vis Sci. 2008;49:1645–1651

Zeaxanthin & Blue Light:
Supplementation with zeaxanthin significantly increased macular pigment in the retina and reduced the damaging effects of blue light to the retina.

The effects of supplementation with lutein and/or zeaxanthin on human macular pigment density and color vision. Ophthalmic and Physiological Optics, 2006 26: 137-147

Zeaxanthin & Visual Performance:
Supplementation with zeaxanthin or lutein increases macular pigment at the fovea (the central part of the macula) and can also improve visual acuity.

Supplementation with the carotenoids lutein or zeaxanthin improves human visual performance Ophthalmic and Physiological Optics, 2006 26: 362-371

Zeaxanthin & Visual Acuity and Visibility:
Increased zeaxanthin supplementation improved visual performance due to changes in underlying biology and/or optical changes.