Fast food, the same meals that expand our waistlines, may shrink our brains, according to research conducted at Oregon Health & Science University in Portland. MSN reports that when researchers studied the memory and cognitive abilities of 104 older people (average age 87) they found that those who performed best had diets high in omega 3 fatty acids and levels of C, D, E and B vitamins. And when they measured the brain volume of 42 of those people with and MRI, they found that the omega 3s correlated with less brain shrinkage. The research also suggests that unhealthy trans-fats found in many fast foods are likely to promote brain shrinking. The researchers believe that nutrient biomarkers in the blood accounted for 37 percent of the variation seen in brain volume and 17 percent in test scores, while other factors such as age, number of years of education and high blood pressure accounted for 46 percent of test score variation. Read an abstract of the study in Neurology.