目前,一項納入250000例觀察對象並發表在American Journal of Clinical Nutrition雜誌上的最新研究"Dietary magnesium intake and risk of stroke: a meta-analysis of prospective studies"表明:常吃富含鎂的食物如綠葉蔬菜、堅果和豆類可以降低卒中風險,但文章作者表示研究結果是從含鎂豐富的食物中得出的,可能會受食物中其他成分的影響。
該項研究的主要作者——瑞典斯德哥爾摩卡羅林斯卡研究所的Susanna Larsson教授認為膳食中鎂的攝入量與卒中(特別是缺血性卒中)風險呈負相關,這項研究結果式建議人們常吃富含鎂的食物如綠葉蔬菜、堅果、豆類和全麥,養成健康飲食的習慣。
Larsson和她的同事檢索了過去45年鎂的攝入量和卒中風險的相關研究文章。其中,在過去14年中發表的七項相關研究,共納入了近250,000例來自美國、歐洲和亞洲的觀察對象,平均隨訪了11.5年。其中有3%(約6500例)的觀察對象在隨訪期間發生了卒中。每日鎂攝入量每增加100mg,缺血性卒中的風險相應降低9%(缺血性卒中是最常見的卒中類型,通常由血凝塊堵塞引起)。該研究所納入的來自美國的觀察對象平均鎂攝入量為242毫克/日。而事實上,美國政府建議,31歲以上的男性和女性每日鎂的攝入量應分別為420毫克和320毫克。在大多數納入的研究中,研究人員能夠排除其他因素的幹擾,如家族史。
但Larsson認為尚不能排除研究結果受觀察者食物中其他成分的影響。想要得出「鎂確實可以降低卒中風險」這一結論之前還需要更多深入的研究。另外其他一些專家認為:該研究結果與飲食推薦指南相一致。北卡羅萊納州杜克大學醫學中心的卒中研究所主任,Larry Goldstein 認為「鎂在水果、蔬菜和穀物中含量豐富,而這些食物均具有低鈉,高鉀和高鎂的特徵。這或許是飲食中各成分的綜合效應,而並不僅僅是某個單一成分的功效。(生物谷Bioon.com)
Dietary magnesium intake and risk of stroke: a meta-analysis of prospective studies
Susanna C Larsson, Nicola Orsini, and Alicja Wolk
Background: Prospective studies of dietary magnesium intake in relation to risk of stroke have yielded inconsistent results.
Objective We conducted a dose-response meta-analysis to summarize the evidence regarding the association between magnesium intake and stroke risk.
Design: Relevant studies were identified by searching PubMed and EMBASE from January 1966 through September 2011 and reviewing reference lists of retrieved articles. We included prospective studies that reported RRs with 95% CIs of stroke for ≥3 categories of magnesium intake. Results from individual studies were combined by using a random-effects model.
Results: Seven prospective studies, with 6477 cases of stroke and 241,378 participants were eligible for inclusion in the meta-analysis. We observed a modest but statistically significant inverse association between magnesium intake and risk of stroke. An intake increment of 100 mg Mg/d was associated with an 8% reduction in risk of total stroke (combined RR: 0.92; 95% CI: 0.88, 0.97), without heterogeneity among studies (P = 0.66, I2 = 0%). Magnesium intake was inversely associated with risk of ischemic stroke (RR: 0.91; 95% CI: 0.87, 0.96) but not intracerebral hemorrhage (RR: 0.96; 95% CI: 0.84, 1.10) or subarachnoid hemorrhage (RR: 1.01; 95% CI: 0.90, 1.14).
Conclusion: Dietary magnesium intake is inversely associated with risk of stroke, specifically ischemic stroke.