Plasma Antioxidant Status in Patients with Alzheimer's Disease and Cognitively Intact Elderly: A Meta-Analysis of Case-Control Studies

source extracted confidence: high 2026-04-09
#aging #alzheimer-disease #antioxidants #biomarkers #humans

Plasma Antioxidant Status in Patients with Alzheimer's Disease and Cognitively Intact Elderly: A Meta-Analysis of Case-Control Studies

Mullan et al., 2018 | J Alzheimers Dis | Meta Analysis

Citation

Mullan Kathryn, Cardwell Chris R, ... McKay Gareth J. Plasma Antioxidant Status in Patients with Alzheimer's Disease and Cognitively Intact Elderly: A Meta-Analysis of Case-Control Studies. J Alzheimers Dis. 2018;62(1):305-317. doi:10.3233/JAD-170758

Abstract

Serum antioxidants may afford neuroprotection against Alzheimer's disease (AD) via correction of the pro-oxidative imbalance but findings reported have been inconsistent. We compared the pooled mean difference in serum levels of ten dietary antioxidants between patients with AD and cognitively intact controls from 52 studies in meta-analyses using random-effects models. Patients with AD had significantly lower plasma levels of α-carotene, β-carotene, lycopene, lutein, vitamin A, C, and E, and uric acid. No significant difference was observed for plasma levels of β-cryptoxanthin and zeaxanthin. Considerable heterogeneity was detected across studies. The lower serum levels of dietary antioxidants from the carotene and vitamin subclasses observed in individuals with AD suggest reduced systemic availability of these subclasses in this prevalent form of dementia. To our knowledge, these are the first meta-analyses to demonstrate lower serum lycopene and to evaluate β-cryptoxanthin, lutein, and zeaxanthin levels in AD. In light of the significant heterogeneity detected across studies, caution should be exercised in the interpretation of the data and therapeutic intervention approaches considered through supplementation measures. Our data may better inform interventions to improve antioxidant status in a condition of major public health importance.

Key Findings

Our data may better inform interventions to improve antioxidant status in a condition of major public health importance.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population ad and cognitively intact
Sample Size 52
Age Range See abstract
Condition cognitive

MeSH Terms

  • Aging
  • Alzheimer Disease
  • Antioxidants
  • Biomarkers
  • Humans
  • Serum

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Journal Article, Meta-Analysis
  • Vertical: vitamin-e

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09