Want to crush it at work? Eat big salads at lunch. Researchers at the Harvard School of Public Health found that men who ate the most vegetables—six servings a day—were 34 percent less likely to develop impaired cognitive function than those who ate the least (two servings).
The study compared diets of 28,000 men over 20 years against tests that measured reasoning, thinking, and memory skills. The green brain gain may be thanks to antioxidant compounds that protect against oxidative stress, which can lead to neurological dysfunction. A cup of raw veg is a serving, so eat a big salad at dinner, too.