This study included 4,213 participants from the Netherlands who did not have dementia with the average age of 66. Questionnaires were filled out by the participants on how much they had consumed of close to 400 items over the past month. Diet quality was examined based on Dutch dietary guidelines for intakes of fruit, vegetables, dairy, whole grain products, nuts, legumes, tea, alcohol, salt, sugary beverages, red and processed meats, unsaturated fats and oils of total fats, and fish. Quality of diet was ranked from 0-14 for each person, with the average diet score being. Best diets consisted of fruit, vegetables, whole grains, nuts, fish, and diary, with limited sugary intakes.
To determine brain volume, numbers of brain white matter lesions and small brain bleeds all participants had brain scans with magnetic resonance imaging. Average total brain volume was 932 milliliters. Researchers collected information on factors such as high blood pressure, smoking, and physical activity which could affect brain volumes.
After adjusting for education, age, sex, physical activity, and smoking it was found that higher diet scores were linked to larger total brain volume, with head size differences being taken into account. Participants with better diets had on average 2 millimeters greater total brain volume. Having a brain volume that is 3.6 millimeters is the equivalent to one year of aging for comparison.
Mediterranean diet plans were also assessed for comparison, and it was found that brain volume results were similar to those participants who had adhered closely to Dutch dietary guidelines.
Single specific food groups did not drive links between better overall quality of diet and larger total brain volume, rather several food groups together due to the many complex interactions that occur across the different food components and nutrients, combinations of healthier foods promote larger brain tissue volumes according to this study.
Limitations were that diet was self reported and relied on memory; it was conducted using Dutch standards and populations so results may vary; and it was a snapshot in time not proving better diets result in larger brain volume only that it is associated.
