[ti:Olive Oil May Protect Our Brain] [by:www.51voa.com] [00:00.00]更多听力请访问51VOA.COM [00:00.12]From VOA Learning English, this is the Health & Lifestyle report. [00:06.12]The health value of a Mediterranean diet is widely known. [00:11.44]Fruits, vegetables and fish are main foods in this diet. [00:17.16]Extra-virgin olive oil is also a major part of the Mediterranean diet. [00:24.24]And new research shows that it may protect the brain [00:28.52]from losing its ability to work properly. [00:32.76]Researchers at Temple University in Philadelphia, Pennsylvania say [00:38.12]extra-virgin olive oil "protects memory and learning ability." [00:44.80]Extra-virgin olive oil, also called EVOO, can reduce the formation of [00:51.20]poisons in the brain that are signs of Alzheimer's disease. [00:57.28]But how does it do it? [00:59.92]Researchers say olive oil reduces inflammation in the brain. [01:05.32]It also activates a cleaning process. [01:09.20]This process is called autophagy. [01:13.12]Autophagy is when cells break down waste and poisons [01:17.24]found between cells and remove them from the body. [01:22.64]There are two substances in the brain [01:25.24]most closely linked to memory loss in Alzheimer's patients: [01:30.44]amyloid plaques and neurofibrillary, or tau tangles. [01:37.16]For definitions of both amyloid plaque and tau tangle, [01:41.88]we go to experts at New Jersey's Rutgers University [01:46.24]and the U.S.-based Alzheimer's Organization. [01:51.40]Amyloid is a protein normally found throughout the body. [01:56.32]However, the experts say when amyloid grows abnormally [02:00.72]it creates a sticky build-up called plaque outside the nerve cells, or neurons. [02:09.40]This abnormal amyloid plaque slowly kills the cells. [02:15.68]Tau proteins are common in the central nervous system. [02:20.72]Tangles form inside dying neurons. [02:25.20]Tangles are twisted fibers of tau protein. [02:29.60]Experts from both organizations explain that, normally, [02:34.36]every neuron contains long fibers made of protein. [02:39.24]These proteins hold the neuron in its proper shape. [02:44.04]They also help to transport nutrients within the neuron. [02:49.96]However, in brains with Alzheimer's disease, [02:53.28]these fibers begin to tangle. [02:56.88]This causes the neuron to lose its shape. [03:00.72]The neuron also becomes unable to transport nutrients. [03:06.20]Over time, it dies. [03:09.20]Domenico Praticò is the lead researcher of the Temple University study. [03:16.60]He says, "brain cells from mice fed diets enriched with extra-virgin olive oil [03:22.36]had higher levels of autophagy" and lower levels of the poisons [03:29.00]-- the amyloid plaques and tau tangles. [03:33.48]For their study, the researchers looked at mice that had three traits of Alzheimer's: [03:39.60]memory loss, amyloid plaques, and tau tangles. [03:45.64]They put the mice into two groups. [03:49.32]Researchers gave one group a diet with extra-virgin olive oil. [03:53.96]They gave the other group a diet without EVOO. [03:59.24]The olive oil was given to the mice when they were only six months old. [04:05.24]This was before any symptoms of Alzheimer's had set in. [04:11.20]At age 9 months and 12 months, the mice in the olive oil group [04:16.76]performed considerably better on tasks [04:19.88]that tested the mice's memory and learning ability. [04:25.40]And, the scientists reported differences in the brain tissues of the two groups. [04:32.16]The brains of the olive oil group showed a great increase in nerve-cell autophagy. [04:39.48]This cell-cleaning process is responsible for the lower levels [04:44.05]of the poisons we talked about earlier [04:46.96]-- the amyloid plaques and tau tangles. [04:51.56]Praticò says that "one thing that stood out immediately [04:55.44]was" the strength of the synapses. [04:58.64]A synapse is the connection between neurons. [05:02.32]It is how they communicate. [05:05.24]The synapses in the mice on the EVOO diet [05:09.04]were stronger than those in the other group. [05:13.16]The researchers say their next step is to see what happens to mice [05:18.20]who are given olive oil at 12 months. [05:22.04]At that time, they will have already begun to show signs of dementia. [05:28.28]Praticò says that patients usually have dementia [05:32.20]when they visit a doctor to investigate signs of the disease. [05:37.56]He says the researchers "want to know whether olive oil [05:41.26]added at a later time in the diet can stop or reverse the disease." [05:47.76]The researchers published their findings online [05:50.92]in the Annals of Clinical and Translational Neurology. [05:55.96]And that's the Health & Lifestyle report. [05:58.36]I'm Anna Matteo. 更多听力请访问51VOA.COM