藍莓汁可能加速老年人的記憶
作者：Emma Hitt, PhD
出處：WebMD醫學新聞
January 26, 2010 — 一項新研究結果顯示，每日攝取市面上販賣的藍莓汁可以改善初期記憶力下降老年人的神經認知功能。
在這第一項補充藍莓汁對老年人神經認知功能的人類研究中，俄亥俄州辛辛那提大學學術健康中心的研究者們發現每日攝取2杯到2杯半野藍莓汁12週後，相較於飲用安慰劑飲料的對應配對受試者，喝藍莓汁的受試者在記憶與學習測試上都有顯著改善。
Robert Krikorian博士寫到，這項初期研究結果顯示，攝取一點藍莓可以轉化為神經認知功能的好處，且建立更詳盡人類臨床試驗的基礎，以研究預防性潛力與神經機轉。
這項研究線上發表於1月4日的農業與食物化學期刊。
【評估抗憂鬱作用】
研究者們指出，過去在實驗室動物的研究顯示，食用藍莓可能協助加速老年人的記憶。然而，直到現在，很少有針對人類補充藍莓效應的科學研究。
為了評估攝取藍莓對老年人記憶力可能有益的假說，研究者們進行了一項為期12週的研究，對象包括9位70歲以上、有輕度、後天記憶力下降的受試者（5位男性與4位女性），他們每天飲用野藍莓汁。
這項研究的主要終點為記憶功能評量，包括口頭配對聯想力測試（the Verbal Paired Associate Learning Test）與加州口頭學習測試（the Verbal Paired Associate Learning Test）。
試驗前以及最終12週的訪談，輪替使用這些記憶測試減輕與使用同樣測試兩次的學習效應。
研究者們也以老年憂鬱指數評估藍莓汁對情緒的影響，也測量體重與腰圍，透過取得空腹血液樣本測量血糖以及胰島素值。
【預防性介入？】
研究者們報告，在12週時，觀察到配對聯想學習力（P=0.009）以及文字回憶能力（P=0.08）改善。他們也指出有憂鬱症狀降低及血糖下降的趨勢。
雖然這項研究的樣本數目很小，研究者們表示，試驗主要與次要終點的效應大小是中度到很大的。
研究作者們寫到，這些初期研究結果令人激勵，且提供補充藍莓可能是阻止或減輕神經退化的一個方法。
他們附帶表示，總體來說，這項起始研究建立了未來補充藍莓作為預防性介入對於認知老化人類研究的基礎。
這項研究由北美藍莓協會及國家衛生研究院贊助。作者們表示已無相關資金上的往來。
Blueberry Juice May Boost Memory in Older Adults
By Emma Hitt, PhD
Medscape Medical News
January 26, 2010 — Daily consumption of commercially available wild blueberry juice improves neurocognitive function in older adults with early memory decline, new research suggests.
In the first human trial to assess blueberry supplementation on neurocognitive function in older adults, investigators at the University of Cincinnati Academic Health Center in Ohio found that after 12 weeks of consuming 2 to 2? cups of wild blueberry juice daily, study subjects showed significant improvement on memory and learning tests compared with their matched counterparts who consumed a placebo beverage.
"The findings of this preliminary study suggest that moderate-term blueberry supplementation can confer neurocognitive benefit and establish a basis for more comprehensive human trials to study preventive potential and neuronal mechanisms," the study authors, led by Robert Krikorian, PhD, write.
The study was published online January 4 in the Journal of Agriculture and Food Chemistry.
Antidepressant Effect Assessed
The investigators point out that previous studies in laboratory animals suggest that eating blueberries may help boost memory in elderly individuals. Until now, however, there has been little scientific work aimed at testing the effect of blueberry supplementation in humans.
To assess the hypothesis that blueberry consumption may have a beneficial effect on memory in older adults, the investigators conducted the 12-week trial, which involved daily supplementation with wild blueberry juice in 9 subjects (5 men and 4 women) 70 years and older who had mild, acquired memory decline.
The study's primary outcomes were measures of memory function, including the Verbal Paired Associate Learning Test and the California Verbal Learning Test.
Alternate forms of these memory tests were used at baseline and at the final 12-week visit to mitigate practice effects associated with using the same test twice.
The investigators also assessed the potential impact of blueberry juice on mood using the Geriatric Depression Scale and also measured weight and waist circumference and assessed serum glucose and insulin values by obtaining fasting blood samples.
Preventive Intervention?
"At 12 weeks, improved paired associate learning (p = 0.009) and word list recall (p = 0.08) were observed," the study authors report. They also noted trends toward reduced depressive symptoms and lower glucose levels.
Although the sample size was small, the investigators note that the effect sizes were moderate to large for both the primary and secondary outcomes.
"These preliminary memory findings are encouraging and suggest that consistent supplementation with blueberries may offer an approach to forestall or mitigate neurodegeneration," the study authors write.
"On balance," they add, "this initial study establishes a basis for further human research of blueberry supplementation as a preventive intervention with respect to cognitive aging."
The study was supported by the Wild Blueberry Association of North America and the National Institutes of Health. The authors have disclosed no relevant financial relationships.
J Agric Food Chem. Published online January 4, 2010.
