手機(jī)版
It's official. That tub of ice-cream really can control your brain and say "eat me."
A U.S. study by UT Southwestern Medical Center at Dallas has found that fat from certain foods such ice-cream and burgers heads to the brain.
Once there, the fat molecules trigger the brain to send messages to the body's cells, warning them to ignore the appetite-suppressing signals from leptin and insulin, hormones involved in weight regulation -- for up to three days.
"Normally, our body is primed to say when we've had enough, but that doesn't always happen when we're eating something good," said researcher Deborah Clegg in a statement.
"What we've shown in this study is that someone's entire brain chemistry can change in a very short period of time. Our findings suggest that when you eat something high in fat, your brain gets "hit" with the fatty acids, and you become resistant to insulin and leptin.
"Since you're not being told by the brain to stop eating, you overeat."
The researchers also found that one particular type of fat -- palmitic acid which is found in beef, butter, cheese and milk, -- is particularly effective at instigating this mechanism.
The study was performed on rats and mice but the scientists say their results, published in The Journal of Clinical Investigation, reinforced common dietary recommendations to limit saturated fat intake as "it causes you to eat more."
The study was conducted by exposing rats and mice to fat in different ways -- by injecting various types of fat directly into the brain, infusing fat through the carotid artery or feeding the animals through a stomach tube three times a day.
The animals received the same amount of calories and fat and only the type of fat differed. The types included palmitic acid, monounsaturated fatty acid and unsaturated oleic acid which is found in olive and grapeseed oils.
"The action was very specific to palmitic acid, which is very high in foods that are rich in saturated-fat," said Clegg.
官方的研究表明：一杯冰激凌確實(shí)能夠控制你的大腦活動(dòng)。它說(shuō)：吃了我吧。
美國(guó)達(dá)拉斯UT西南醫(yī)學(xué)中心的一項(xiàng)研究發(fā)現(xiàn)，某些食物，如冰激凌和漢堡包，其中所含的脂肪直接刺激人的大腦。
當(dāng)人攝入了哪些食物，脂肪分子就開(kāi)始刺激大腦向體細(xì)胞發(fā)送消息，警告它們忽略那些由瘦素、胰島素以及用于體重控制的荷爾蒙所產(chǎn)生的控制食欲的信號(hào)，這種刺激可長(zhǎng)達(dá)三天的時(shí)間。
研究者Deborah Clegg在一次陳述中說(shuō)道，"正常來(lái)說(shuō)，當(dāng)我們飽食時(shí)，我們的身體最先有反應(yīng)。但是，當(dāng)我們正在吃一些好的食物時(shí)，情況往往就不是那樣了。
"在這項(xiàng)研究中，我們所要表明的是一個(gè)人大腦的全部化學(xué)成分能夠在非常短暫的時(shí)間內(nèi)發(fā)生變化。我們的發(fā)現(xiàn)成果表明，當(dāng)你攝入了富含脂肪的食物時(shí)，你的大腦受到脂肪酸的刺激，隨之你的身體也開(kāi)始抵制胰島素和瘦素。
"因?yàn)榇竽X沒(méi)有告訴你停止攝入食物，你就會(huì)過(guò)量飲食。"
研究者們也發(fā)現(xiàn)了一種富含于牛肉、黃油、干酪和牛奶的特殊脂肪--棕櫚酸，對(duì)促成這種機(jī)制有專(zhuān)門(mén)的功效。
這項(xiàng)研究是用白鼠和黑鼠做實(shí)驗(yàn)的，而這些科學(xué)家說(shuō)，他們的科研成果被刊登在《臨床研究期刊》上，該成果證實(shí)了公認(rèn)的飲食規(guī)定建議來(lái)限制飽和脂肪攝入量，因?yàn)轱柡椭究梢宰屇愠缘酶唷?/p>
研究者們是通過(guò)用不同途徑給白鼠和黑鼠攝入脂肪來(lái)進(jìn)行這項(xiàng)研究的。他們直接把不同種類(lèi)的脂肪注射進(jìn)大腦里，或通過(guò)解剖頸動(dòng)脈注入脂肪，或者通過(guò)胃管給動(dòng)物喂食物，一日三次。
這些動(dòng)物攝入了等量的卡路里和脂肪，并且其中只有一種脂肪是不同的。這些脂肪種類(lèi)中包括棕櫚酸、單不飽和脂肪酸和富含于橄欖油和葡萄油中的不飽和油酸。
Clegg說(shuō)："這項(xiàng)研究可以具體到棕櫚酸，這種酸在富含飽和脂肪的食物中含量非常高。"
