Low Xanthophylls, Retinol, Lycopene, and Tocopherols in Grey and White Matter of Brains with Alzheimer’s Disease

Abstract

Background: Oxidative stress contributes to pathogenesis and progression of Alzheimer’s disease (AD). Higher levels of the dietary antioxidants— carotenoids and tocopherols— are associated with better cognitive functions and lower risk for AD, and lower levels of multiple carotenoids are found in serum and plasma of patients with AD. Although brains donated by individuals with mild cognitive impairment had significantly lower levels of lutein and beta-carotene, previous investigators found no significant difference in carotenoid levels of brains with AD and cognitively normal brains. Objective: This study tested the hypothesis that micronutrients are significantly lower in donor brains with AD than in healthy elderly brains. Methods: Samples of donor brains with confirmed AD or verified health were dissected into grey and white matter, extracted with organic solvents analyzed by HPLC. Results: AD brains had significantly lower levels of lutein, zeaxanthin, anhydrolutein, retinol, lycopene, and alpha-tocopherol, and significantly increased levels of XMiAD, an unidentified xanthophyll metabolite. No meso-zeaxanthin was detected. The overlapping protective roles of xanthophylls, carotenes, α- and γ-tocopherol are discussed. Conclusion: Brains with AD had substantially lower concentrations of some, but not all, xanthophylls, carotenes, and tocopherols, and several-fold higher concentrations of an unidentified xanthophyll metabolite increased in AD (XMiAD).

Association of dietary and nutritional factors with cognitive decline, dementia, and depressive symptomatology in older individuals according to a neurogenesis-centred biological susceptibility to brain ageing

“…Contrary to some previous studies [ 58 , 59 ], we also found a positive association between plasma lycopene concentrations—a carotenoid biomarker—and AD risk, but only in individuals with a neurogenesis-centred biological susceptibility. However, overall, there is insufficient evidence to draw firm conclusions or tease apart direct effects of lycopene on future dementia risk [ 60 ], so it is presently unclear what this finding represents in the wider context of AD.…”

Plant Pigments in Psychiatry and Neurology: Historical and Modern Uses. Part Ii. A Literature Review With a Clinical Case Presentation

“…Кроме того, было также показано, что как в сером (нейрональном), так и в белом (глиальном) веществе головного мозга (ГМ) пациентов с болезнью Альцгеймера (БА) или с до-клиническими лёгкими когнитивными нарушениями (КН) -значительно снижено содержание ликопина, ретинола, ксантофиллов (в частности, лютеина и зеаксантина), токоферолов [12].…”