Trial reportPloS one2014
A double-blind, placebo-controlled study on the effects of lutein and zeaxanthin on neural processing speed and efficiency.
Trial report in PloS one, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 50 papers, 3 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
50 citing papers in PubMed, 3 syntheses or guidelines pooled it, 99 citations in OpenAlex.
- The Effect of Lutein/Zeaxanthin Intake on Human Macular Pigment Optical Density: A Systematic Review and Meta-Analysis.Advances in nutrition (Bethesda, Md.) · 2021Pooled it
- Dietary Lutein and Cognitive Function in Adults: A Meta-Analysis of Randomized Controlled Trials.Molecules (Basel, Switzerland) · 2021Pooled it
- Pooled it
- The effect of macular carotenoids and omega-3 supplementation on performance in precision sports: the sport nutrition intervention in performance exercise (SNIPE) study.Frontiers in nutrition · 2026Trial
- Randomized, Placebo-Controlled, Single-Blind Study of Lutein Supplementation on Carotenoid Status and Cognition in Persons with Multiple Sclerosis.The Journal of nutrition · 2023Trial
- Goji Berry Intake Increases Macular Pigment Optical Density in Healthy Adults: A Randomized Pilot Trial.Nutrients · 2021Trial
- Trial
- Cognitive Function and Its Relationship with Macular Pigment Optical Density and Serum Concentrations of its Constituent Carotenoids.Journal of Alzheimer's disease : JAD · 2015Trial
- International Society of Sports Nutrition position stand: effects of dietary antioxidants on exercise and sports performance.Journal of the International Society of Sports Nutrition · 2026Review
- Lutein and Zeaxanthin: Source, Extraction, Stability, Bioactivity, and Functional Food Applications.Current pharmaceutical biotechnology · 2026Review
- Article
- Macular Pigment Carotenoid Supplementation for the Preservation of Visual Structure and Function Following a Collegiate Rugby Season.Eye and brain · 2025Article
- Review
- Effect of supplementation with lutein, zeaxanthin, and omega-3 fatty acids on macular pigment and visual function in young adults with long-term use of digital devices: study protocol for a randomized double-blind placebo-controlled study.Frontiers in nutrition · 2024Article
- Review
- Low Xanthophylls, Retinol, Lycopene, and Tocopherols in Grey and White Matter of Brains with Alzheimer's Disease.Journal of Alzheimer's disease : JAD · 2023Review
- Early Childhood Lutein and Zeaxanthin Intake Is Positively Associated with Early Childhood Receptive Vocabulary and Mid-Childhood Executive Function But No Other Cognitive or Behavioral Outcomes in Project Viva.The Journal of nutrition · 2022Article
- Carotenoids improve the development of cerebral cortical networks in formula-fed infant macaques.Scientific reports · 2022Article
- Sex Differences Across the Life Course: A Focus On Unique Nutritional and Health Considerations among Women.The Journal of nutrition · 2022Article
- Dietary antioxidants associated with slower progression of parkinsonian signs in older adults.Nutritional neuroscience · 2022Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Lutein and zeaxanthin are major carotenoids in the eye but are also found in post-receptoral visual pathways. It has been hypothesized that these pigments influence the processing of visual signals within and post-retina, and that increasing lutein and zeaxanthin levels within the visual system will lead to increased visual processing speeds. To test this, we measured macular pigment density (as a biomarker of lutein and zeaxanthin levels in brain), critical flicker fusion (CFF) thresholds, and visual motor reaction time in young healthy subjects (n = 92). Changes in these outcome variables were also assessed after four months of supplementation with either placebo (n = 10), zeaxanthin only (20 mg/day; n = 29) or a mixed formulation containing 26 mg/day zeaxanthin, 8 mg/day lutein, and 190 mg/day mixed omega-3 fatty acids (n = 25). Significant correlations were found between retinal lutein and zeaxanthin (macular pigment) and CFF thresholds (p<0.01) and visual motor performance (overall p<0.01). Supplementation with zeaxanthin and the mixed formulation (considered together) produced significant (p<0.01) increases in CFF thresholds (∼12%) and visual motor reaction time (∼10%) compared to placebo. In general, increasing macular pigment density through supplementation (average increase of about 0.09 log units) resulted in significant improvements in visual processing speed, even when testing young, healthy individuals who tend to be at peak efficiency.
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What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.