Study finds no additional benefit from (RS) meso-zeaxanthin

A study showed the addition of (RS) meso-zeaxanthin, a non-dietary carotenoid found in many eye health supplements, contributes no additional efficacy for eye health, in people with non-advanced age-related macular degeneration  

The study, co-authored by John Nolan, Macular Pigment Research Group at Waterford Institute of Technology, was presented at the Eighteenth International Symposium on Carotenoids in Lucerne, Switzerland.

The findings from the Central Retinal Enrichment Supplementation Trials (CREST) adds doubt to the need for supplement formulations containing (RS) meso-zeaxanthin.

The CREST study examined the effect of adding (RS) meso-zeaxanthin to the standard National Eye Institute’s Age-Related Eye Disease Study 2 (AREDS2) formula of 10 mg lutein and 2 mg zeaxanthin, plus low zinc.

The study participants were randomly assigned to one of two AREDS2 (with low zinc) treatment groups: with 10 mg (RS) meso-zeaxanthin or no (RS) meso-zeaxanthin. After 24 months of follow-up in 98 participants with non-advanced age-related macular degeneration (early AMD), there were no significant differences in measures of macular pigment or visual function between the treatments.1

Richard Roberts, Kemin Principal Manager at Technical Services, said: “Supplement manufacturers should be aware that all zeaxanthin is not the same. Some products are misrepresented as containing natural and dietary zeaxanthin but contain a non-dietary, synthetic, zeaxanthin stereoisomer—3R, 3’S- zeaxanthin, or (RS) meso-zeaxanthin, which is one of three zeaxanthin stereoisomers.

The findings are important because they build on the available evidence that suggests there is no additional benefit of adding (RS) meso-zeaxanthin to eye health supplements.

(RS) Meso-zeaxanthin contained in dietary supplements is synthetically made from lutein using high heat and a strong alkaline environment.2 Research also indicates (RS) meso-zeaxanthin present in the macula is made from dietary lutein and supplemental (RS) meso-zeaxanthin may actually compete with lutein and zeaxanthin for absorption, keeping these important antioxidants from reaching the macula in the amounts needed for eye health.3,4,5

Ceci Snyder, Global Vision Product Manager, said: “Eye health supplement formulators should ask if all ingredients used in their product formulations are supported by science for safety and effectiveness.”

FloraGLO Lutein, which contains the same dietary forms of lutein and zeaxanthin as found in common foods such as spinach, kale and broccoli, is a quality lutein backed by scientific research. FloraGLO is supported by over 80 human clinical trial publications and is the number one recommended lutein brand by eye doctors.6

Study participants were diagnosed with early AMD. The findings continue to support the National Eye Institute’s AREDS2 formulation with 10 mg of FloraGLO Lutein and 2 mg zeaxanthin as the standard eye health supplement formulation for age-related eye conditions.

The research conducted was possible becuase of a European Research Council grant for CREST. The research was conducted at the Macular Pigment Research Group, which is part of the Nutrition Research Centre Ireland at the School of Health Science, Waterford Institute of Technology in Waterford, Ireland.


  1. Akuffo KO, et al., "The impact of supplemental antioxidants on visual function in non-advanced age-related macular degeneration: a head-to-head randomized clinical trial." Presented at Eighteenth International Symposium on Carotenoids, Lucerne, Switzerland (2017).
  2. R. Bone, et al., Invest Ophthalmol Vis Sci. 34, 2033–2040 (1993).
  3. D. Thurnham and A Howard, Food Chem Toxicol. 59, 455–463 (2013).
  4. DI Thurnham, et. al., Br J Nutr. 100, 1307–1314 (2008).
  5. KA Meagher, et al., Br J Nutr. 110, 289–300 (2013).
  6. Based on the results of the National Disease and Therapeutic Index syndicated report among physicians who recommend a dietary supplement with lutein for eye health (December 2014, December 2015).

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