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 spinach（菠菜）, kale（甘蓝） 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.