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The impact of supplemental macular carotenoids in Alzheimer’s disease: A randomized clinical trial


Nolan, John M., Loskutova, Ekaterina, Howard, Alan, Mulcahy, Riona, Moran, Rachel, Stack, Jim, Bolger, Maggie, Coen, Robert F., Dennison, Jessica, Akuffo, Kwadwo Owusu, Owens, Niamh, Power, Rebecca, Thurnham, David, Beatty, Stephen


Journal of Alzheimer's Disease, Volume: 44, No.: 4, Pages.: 1157-1169

Year of Publication



Background: Patients with Alzheimer’s disease (AD) exhibit significantly less macular pigment (MP) and poorer vision when compared to control subjects. Objective: To investigate supplementation with the macular carotenoids on MP, vision, and cognitive function in patients with AD versus controls. Methods: A randomized, double-blind clinical trial with placebo and active arms. 31 AD patients and 31 age-similar control subjects were supplemented for six months with either Macushield (10 mg meso-zeaxanthin [MZ]; 10 mg lutein [L]; 2mg zeaxanthin [Z]) or placebo (sunflower oil). MP was measured using dual-wavelength autofluorescence (Heidelberg Spectralis®). Serum L, Z, and MZ were quantified by high performance liquid chromatography. Visual function was assessed by best corrected visual acuity and contrast sensitivity (CS). Cognitive function was assessed using a battery of cognition tests, including the Cambridge Neuropsychological Test Automated Battery (CANTAB). Results: Subjects on the active supplement (for both AD and non-AD controls) exhibited statistically significant improvement in serum concentrations of L, Z, MZ, and MP (p < 0.001, for all) and also CS at (p = 0.039). Also, for subjects on the active supplement, paired samples t-tests exhibited four significant results (from five spatial frequencies tested) in the AD group, and two for the non-AD group, and all indicating improvements in CS. We found no significant changes in any of the cognitive function outcome variables measured (p > 0.05, for all). Conclusion: Supplementation with the macular carotenoids (MZ, Z, and L) benefits patients with AD, in terms of clinically meaningful improvements in visual function and in terms of MP augmentation. (PsycINFO Database Record (c) 2015 APA, all rights reserved). (journal abstract)


age differences, agerelated macular degeneration, alzheimer’s disease, catotenoids, clinical trials, cognitive ability, cognitive function, contrast sensitivity, drug therapy, l, lutein, luteinizing hormone, macular, mesozeaxanthin, mg, mz, pigments, problems, randomized clinical trial, vision, visual function, z, zeaxanthin

Countries of Study


Types of Dementia

Alzheimer’s Disease

Types of Study

Randomised Controlled Trial

Type of Outcomes

Cognition, Risk reduction (of dementia and co-morbidities)

Type of Interventions

Pharmaceutical Interventions

Pharmaceutical Interventions

Anti-Alzheimer medications, e.g.: donezepil, galantamine, rivastigmine, memantime