Lecithin for dementia and cognitive impairment

  • Review
  • Intervention

Authors


Abstract

Background

Alzheimer's disease sufferers have been found to lack the enzyme responsible for converting choline into acetylcholine within the brain. Lecithin is a major dietary source of choline, so extra consumption may reduce the progression of dementia.

Objectives

To determine the efficacy of lecithin in the treatment of dementia or cognitive impairment.

Search methods

The Cochrane Dementia and Cognitive Improvement Group's Specialized Register was searched on 6 May 2004 using the terms lecithin and phosphatidylcholine. This register contains records from all major databases and many trials databases and is updated regularly. Reference lists and relevant books have been examined.

Selection criteria

All unconfounded, randomized trials comparing lecithin with placebo in a treatment period longer than one day, in patients with dementia of the Alzheimer type, vascular dementia, mixed vascular and Alzheimer's disease, unclassified or other dementia or unclassified cognitive impairment not fulfilling the criteria for dementia are eligible for inclusion.

Data collection and analysis

Data were extracted independently by two reviewers and cross-checked. Meta-analyses were performed when more than one trial provided data on a comparable outcome on sufficiently similar patients. Random effects analyses were performed whenever heterogeneity between results appeared to be present. Standardised differences in mean outcome measures were used due to the use of different scales and periods of treatment. Odds ratios for dichotomous data were pooled using the Mantel-Haenszel or DerSimonian and Laird methods.

Main results

Twelve randomized trials have been identified involving patients with Alzheimer's disease (265 patients), Parkinsonian dementia (21 patients) and subjective memory problems (90 patients). No trials reported any clear clinical benefit of lecithin for Alzheimer's disease or Parkinsonian dementia. Few trials contributed data to meta-analyses. The only statistically significant result was in favour of placebo for adverse events, based on one trial, which appears likely to be a spurious result. A dramatic result in favour of lecithin was obtained in a trial of subjects with subjective memory problems.

Authors' conclusions

Evidence from randomized trials does not support the use of lecithin in the treatment of patients with dementia. A moderate effect cannot be ruled out, but results from the small trials to date do not indicate priority for a large randomized trial.

摘要

背景

使用卵磷酯治療失智跟認知損傷

阿茲海默症患者大腦中缺乏可以將膽鹼轉變為乙醯膽鹼的酵素,飲食中的卵磷酯是膽鹼的主要來源,因此額外攝取可以減少失智形成。

目標

本研究的主要目的在於評估使用卵磷酯治療失智跟認知損傷的療效。

搜尋策略

在2004年5月6號使用「lecithin and phosphatidylcholine」等關鍵字針對Cochrane Dementia and Cognitive Improvement Group's Specialized Register資料庫進行檢索,此資料庫包含從主要資料庫到臨床資料庫並且有進行規律的更新,並檢視參考文獻跟相關書籍。

選擇標準

選擇標準如下: 1.未受干擾、隨機分配試驗。 2.採用lecithin與安慰劑進行比較,治療期間需超過1天。 2.病人為阿茲海默症、血管型失智症、混合以上兩種、未區分失智症種類、或其他失智症或是認失損傷不過還不符合認定為失智症者。

資料收集與分析

2位作者獨立摘錄數據,並且進行交叉比對。 若有超過1個研究提供充足、種類相似病人的可比較數據,則進行統合分析(Metaanalyses)。若研究結果有異質性,則進行隨機效果分析。由於各研究所使用的評量尺度及進行時間不一,因此使用平均結果標準差。二分項數據的勝算比使用MantelHaenszel 或 DerSimonian及Laird 方法合併。

主要結論

找到了12個隨機分配的試驗,共有265未阿茲海默患者、21位帕金森失智患者以及90位主觀記憶有問題患者。沒有一個試驗指出lecithin對於阿茲海默症或帕金森症有臨床療效。少數試驗的數據可以進行統合分析, 而唯一顯著的結果指出在不良反應方面較偏好使用安慰劑,不過該研究結果很可能是虛構的。 不過我們在1個試驗當中,發現戲劇化的結果顯示主觀記憶問題的患者較偏好使用lecithin。

作者結論

隨機分配試驗的證據不能支持使用卵磷脂治療失智病人,一個適當結果並不能被排除,不過來自小型試驗的結果並沒有指出未來大型試驗應該要優先進行的項目。

翻譯人

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

卵磷脂用於治療失智的結果令人懷疑的,卵磷脂是飲食中膽鹼主要來源,理論上它具有改善失智或相似問題(阿茲海默症)人大腦的功能,此篇文章並沒有發現卵磷脂可以對阿茲海默症或失智的病人有幫助的證據。然而,小型試驗可觀察到卵磷脂對患有主觀性記憶問題的人有顯著的益處,但並沒有相似的試驗可以去比較。

Plain language summary

Doubtful effect of lecithin as a treatment for dementia

Lecithin is a major dietary source of choline, a substance that may theoretically improve brain functioning in people with dementia or similar problems (including Alzheimer's disease). This review did not find any evidence that lecithin does have a benefit for patients with Alzheimer's disease or other forms of dementia. However, one small study has observed a dramatic benefit of lecithin in people with subjective memory problems, but there are no similar studies with which to compare it.

Laički sažetak

Učinak lecitina u liječenju demencije je upitan

Lecitin je glavni izvor kolina koji se uzima putem hrane. Kolin je tvar koja teoretski može poboljšati moždanu funkciju u ljudi s demencijom ili sličnim problemima (uključujući Alzheimerovu bolest). Ovaj Cochrane sustavni pregled nije našao dokaze o koristi lecitina kod bolesnika s Alzheimerovom bolesti ili drugim oblicima demencije. Međutim, jedna mala studija opazila je izrazitu korist lecitina u ljudi sa subjektivnim problemima pamćenja, ali nema sličnih studija s kojima bi se ona usporedila.

Bilješke prijevoda

Hrvatski Cochrane
Prevela: Katarina Vučić
Ovaj sažetak preveden je u okviru volonterskog projekta prevođenja Cochrane sažetaka. Uključite se u projekt i pomozite nam u prevođenju brojnih preostalih Cochrane sažetaka koji su još uvijek dostupni samo na engleskom jeziku. Kontakt: cochrane_croatia@mefst.hr