Eating vegetables, but not fruits, can help slow the rate of mental decline in older adults. Researchers studied more than 3,700 Chicago seniors, who completed food frequency questionnaires and two or more cognitive tests over the course of six years.
Those who ate 2.8 servings of vegetables a day or more slowed their rate of cognitive decline by roughly 40 percent, the equivalent of about five years. Green leafy vegetables had the strongest effect, and the older the person, the greater the slowdown in mental decline.
Fruit consumption was not associated with cognitive change, which may be due to the fact that vegetables contain higher amounts of vitamin E. Vegetables are also often consumed with fats such as salad dressings that increase the absorption of vitamin E.