多吃蔬菜能保大脑年轻

 New research on vegetables and aging gives mothers another reason to say "I told you so." It found that eating vegetables appears to help keep the brain young and may slow the mental decline sometimes associated with growing old.

On measures of mental sharpness, older people who ate more than two servings of vegetables daily appeared about five years younger at the end of the six-year study than those who ate few or no vegetables.

The research in almost 2,000 Chicago-area men and women doesn't prove that vegetables reduce mental decline, but it adds to mounting evidence pointing in that direction. The findings also echo previous research in women only.

Green leafy vegetables including spinach¹, kale and collards appeared to be the most beneficial. The researchers said that may be because they contain healthy amounts of vitamin E, an antioxidant that is believed to help fight chemicals produced by the body that can damage cells.

Vegetables generally contain more vitamin E than fruits. Vegetables also are often eaten with healthy fats such as salad oils, which help the body absorb vitamin E and other antioxidants, said lead author Martha Clare Morris, a researcher at Chicago's Rush University Medical Center. 

The fats from healthy oils can help keep cholesterol² low and arteries³ clear, which both contribute to brain health.

The study was published in this week's issue of the journal Neurology and funded with grants from the National Institute on Aging.

The research involved 1,946 people aged⁴ 65 and older who filled out questionnaires about their eating habits. A vegetable serving equaled about a half-cup chopped or one cup if the vegetable was a raw leafy green like spinach. They also had mental function tests three times over about six years.

 The tests included measures of short-term and delayed memory, which asked these older people to recall elements of a story that had just been read to them. The participants also were given a flashcard-like exercise using symbols and numbers. 

1 spinach   

n.菠菜

参考例句：

• Eating spinach is supposed to make you strong.据说吃菠菜能使人强壮。
• You should eat such vegetables as carrot,celery and spinach.你应该吃胡萝卜、芹菜和菠菜这类的蔬菜。

2 cholesterol   

n.（U）胆固醇

参考例句：

• There is cholesterol in the cell of body.人体细胞里有胆固醇。
• They are determining the serum-protein and cholesterol levels.他们正在测定血清蛋白和胆固醇的浓度。

3 arteries   

n.动脉( artery的名词复数 )；干线，要道

参考例句：

• Even grafting new blood vessels in place of the diseased coronary arteries has been tried. 甚至移植新血管代替不健康的冠状动脉的方法都已经试过。 来自《简明英汉词典》
• This is the place where the three main arteries of West London traffic met. 这就是伦敦西部三条主要交通干线的交汇处。 来自《简明英汉词典》

4 aged   

adj.年老的，陈年的

参考例句：

• He had put on weight and aged a little.他胖了，也老点了。
• He is aged,but his memory is still good.他已年老，然而记忆力还好。