Nutrition and health

Objectives:
There is an ongoing debate on the involvement of systemic copper (Cu) dysfunctions in Alzheimer's disease (AD) and clinical studies comparing Cu levels in serum, plasma and cerebrospinal fluid (CSF) of AD patients with those of healthy controls have delivered non-univocal and often conflicting results. Therefore, this review article has been conducted.

Does blood level of copper increase in Alzheimer’s disease?

Study design:
This review article included 26 studies including a pooled total of 761 AD subjects and 664 controls for serum Cu studies, 205 AD subjects and 167 controls for plasma Cu and of 116 AD subjects and 129 controls for CSF Cu.

Results and conclusions:
The investigators found Alzheimer's disease patients have higher levels of serum copper than healthy controls. Plasma data did not allow conclusions, due to their high heterogeneity, but the meta-analysis of the combined serum and plasma studies confirmed higher copper levels in Alzheimer's disease patients. 

The investigators found the analysis of CSF data revealed no difference between Alzheimer's disease patients and controls.

The investigators concluded Alzheimer's disease patients have higher levels of serum and plasma copper than healthy controls.

Original title:
Copper in Alzheimer's disease: a meta-analysis of serum, plasma, and cerebrospinal fluid studies by Bucossi S, Ventriglia M, […], Squitti R.

Link:
http://www.ncbi.nlm.nih.gov/pubmed/21187586

Additional information of El Mondo:
Find more information/studies on copper and dementia right here.

Objectives:
Lutein and zeaxanthin are thought to have beneficial effects on protecting the lens against cataract formation, but findings from epidemiologic studies have been inconsistent. Therefore, this review article has been conducted.

Does dietary lutein and zeaxanthin intake reduce age-related cataract risk?

Study design:
This review article included 6 prospective cohort studies, involving 4416 cases and 41999 participants.

Results and conclusions:
The investigators found for comparing the highest with the lowest categories of dietary lutein and zeaxanthin intake, a significant reduced risk for nuclear cataract of 25% [RR = 0.75, 95% CI = 0.65-0.85], but the reduced risk was not significant for cortical cataract [RR = 0.85, 95% CI = 0.53-1.17] and for posterior subcapsular cataract [RR = 0.77, 95% CI = 0.40-1.13]. Significant means, there is an association with a 95% confidence.

The investigators found in dose-response analysis that every 300 μg/d increment in dietary lutein and zeaxanthin intake was significantly associated with a 3% [RR = 0.97, 95% CI = 0.94-0.99] reduction in the risk of nuclear cataract.

The investigators found in dose-response analysis that every 300 μg/d increment in dietary lutein and zeaxanthin intake was non-significantly associated with a 1% [RR = 0.99, 95% CI = 0.95-1.02] reduction in the risk of cortical cataract. Non-significantly means, there is no association with a 95% confidence.

The investigators found in dose-response analysis that every 300 μg/d increment in dietary lutein and zeaxanthin intake was non-significantly associated with a 3% [RR = 0.97, 95% CI = 0.93-1.01] reduction in the risk of posterior subcapsular cataract. Non-significantly because RR of 1 was found in 95% CI of 0.93 to 1.01. RR of 1 means no risk.

The investigators concluded dietary lutein and zeaxanthin intake (at least 300 μg/d) is associated with a reduced risk of age-related cataract, especially nuclear cataract in a dose-response manner, indicating a beneficial effect of lutein and zeaxanthin in age-related cataract prevention.

Original title:
A dose–response meta-analysis of dietary lutein and zeaxanthin intake in relation to risk of age-related cataract by Ma L, Hao ZX, [...], Pan JP.

Link:
http://link.springer.com/article/10.1007/s00417-013-2492-3

Additional information of El Mondo:
Find more studies/information on elderly right here.