來自Sheffield大學研究人員的一項前沿性研究發現,血型在神經係統的發育中起到了一定的作用，而且，血型可能會有高風險引起認知下降。

　　這項研究是與威尼斯的IRCCS San Camillo醫院基金會合作開展的，研究發現，O型血的人與其它血型的人相比，如A、B或AB血型，大腦中有更多的灰質，從而保護他們不易得老年癡呆症。

　　來自Sheffield大學神經科學係的研究人員Matteo De Marco和Annalena Venneri教授，分析了189名健康誌願者的核磁共振成像結果。他們計算了這些誌願者大腦中的灰質含量，並研究了灰質量在不同血型間的差異。

　　研究結果發表在Brain Research Bulletin雜誌上，即O型血的人們在小腦後部有更多的灰質。相比之下，A、B及AB血型的人們，有小量的灰質，在腦的顳部和邊緣區域，包括左海馬，此區域是老年癡呆症最早受損的大腦的部位之一。

　　這些發現提示，小量的灰質是與非O型血相關的。

　　隨著年齡的增長，通常大腦中的灰質量是呈下降趨勢的。但是，血型的差異會加劇由老化引起的灰質量的不同。

　　"這些發現似乎表明，O型血的人們不易得一些由大腦顳部或顳部內側灰質量減少所引起的疾病，例如老年癡呆症，"Matteo DeMarco說。

　　"然而，仍需要其他的檢測和進一步的研究，因為可能有另外的生物機製也包括在內。"

　　Annalena Venneri教授補充道，"我們現在知道了大腦灰質量的明顯差異，我們的發現也證實了臨床上所觀察到的。血型很可能影響了神經係統的發育。現在我們將研究這是如何和為什麼發生的。"

　　推薦英文原文報道: Links found between blood type and risk of cognitive decline

　　推薦的英文原文

　　‘O’ blood type is associated with larger grey-matter volumes in the cerebellum

　　dx.doi.org/10.1016/j.brainresbull.2015.05.005

　　Recent evidence indicated higher incidence of cognitive deficits in ABO blood-type system ‘AB’ individuals. Since this statistical difference might originate from the lack of protective effects exerted by ‘O’ alleles on the brain via vascular or non-vascular routes, this study investigated volumetric differences in grey matter between ‘O’ and non-‘O’ adults to explore the possibility of a structural endophenotype visible in ‘O’ adults without cognitive impairment or neurodegeneration.

　　A large sample of cognitively healthy adults who had previously undergone structural MRI for research purposes were contacted telephonically and enquired about their ABO blood type. Out of the 189 individuals who were able to retrieve and communicate this information, ‘O’ (n = 76) and ‘A’ adults (n = 65) were included in Model 1. In Model 2, all non-‘O’ (n = 113) were instead collapsed in a single group. Voxel-Based Morphometry analyses were carried out on three-dimensional T1-weighted scans, and between-sample t tests were run to compare the maps of grey-matter volumes of the subgroups of interest, controlling for major nuisance variables.

　　In Model 1, ‘O’ adults had larger grey-matter volumes in two symmetrical clusters within the posterior ventral portion of the cerebellum. This was confirmed in Model 2. Additionally, non-‘O’ adults showed lower volume values in temporal and limbic regions, including the left hippocampus.

　　The cerebellar clusters were located in regions previously found to be part of a network responsible for sensorimotor integration. It is speculated that the structural reductions seen in non-‘O’ adults might result in a susceptibility to down-regulation of this network. This occurrence is likely to intensify along the ageing process and may contribute to foster cognitive decline. Although Model 2 seems to suggest that having a ‘O’ blood type might play a role in protection against those conditions in which temporal and mediotemporal volumetric loss is observed (Alzheimer's disease), additional supporting evidence is needed.

　　A number of potential biological processes might sustain these between-group differences, including sensorimotor ontogenesis, hormonal function, and a regional impact of cerebral amyloid angiopathy. These findings identify the cerebellar tissue as a candidate for further studying ABO function, and support a general association between ABO blood type and variance in the development of the nervous system.