以前常聽說心情與糖的關係，據說甜味會讓人快樂。那麼，記憶與糖呢?這二者可存在什麼關係?
Memory and Sugar
Sugar On The Brain
It’s long been understood that there is a connection between memory problems and diabetes, a disorder characterized by excessively high blood sugar. Sugar provides the body with fuel for various processes, including memory processing. In fact, glucose carried in the blood stream supplies the brain with 90 percent of the energy it requires to function properly.
In order to fuel those processes glucose has to get from the blood to the tissues, where it can be broken down and put to work. High blood sugar levels, such as in diabetes, are an indicator that a body is experiencing difficulty moving sugar from the blood to the tissues.
However, some non-diabetics have a less severe form of high blood sugar, a condition called impaired glucose tolerance. And it is this condition that seems to be the cause of memory problems in a significant number of non-diabetic elderly people who experience memory difficulties.
Sweet Nothings
Subjects were given glucose intravenously, and then researchers measured how quickly glucose moved from the blood to the tissues. Next the subjects were tested for overall cognitive functioning and the ability to recall short paragraphs. The results? Subjects who scored lowest on memory recall tests also showed impaired glucose tolerance.
In addition, brain scans demonstrated that these same subjects each had a significantly smaller hippocampus, a brain area important to learning and memory. The researchers hypothesize that impaired glucose tolerance may over time cause damage and atrophy to the hippocampus.
What can a body do to prevent this? A healthy diet and exercise can help maintain good glucose tolerance, perhaps preventing gradual memory decline.
記憶與糖
大腦中的糖
健忘與糖尿病有關，這個人們早就知道。糖尿病是一種以血液中含糖量過高為特徵的`疾病。糖為身體的各項功能提供能量，其中就包括記憶功能。事實上，血液中的葡萄糖為腦部功能正常運作提供了90%的能量。
為了給這些功能提供能量，葡萄糖必需從血液進入到身體組織中，在那裡葡萄糖得到分解併發揮效用。血液中含糖量太高，比如糖尿病就是這樣，表明身體在將糖從血液運輸到身體組織時發生困難。
然而，一些非糖尿病患者，他們體內含糖量高的病症較輕微，這種病叫做葡萄糖耐受性受損。而廣大記憶產生障礙的老年非糖尿病患者會發生記憶衰退就是由該病導致。
"無用武之地"的糖
研究人員向實驗物件進行靜脈注射，然後測量葡萄糖從血液運輸到身體組織中有多快。接下來，研究人員測驗實驗物件總體認知功能及記憶短句的能力。結果如何?在記憶環節得分最低的實驗物件，同時也表現出葡萄糖耐受性受損的症狀。
此外，大腦掃描表明患有該病的此類實驗物件，大腦中對學習記憶非常重要的部位──海馬體，很明顯體積較小。研究人員猜測葡萄糖耐受性衰退可能長期對海馬體造成傷害使其萎縮。
那麼我們該如何預防此類疾病呢?健康的飲食和進行鍛鍊有助於保持良好的葡萄糖耐受性，這也許可以防止記憶衰退。
