A new study from the Netherlands reveals that people that eat a diet primarily of vegetables, fruit, nuts and fish have larger brains than those eating less of those healthy foods.
The study’s senior author, Dr. Meike Vernooij explained the results:
“Adhering to an overall healthy diet quality supports brain health and might be a suitable preventive strategy to maintain and augment cognition [thinking and memory] in healthy older adults,” she said.
Dr. Vernooij is a professor of population imaging at Erasmus University Medical Center in Rotterdam.
The research followed over 4,200 subjects over 45 years old. The average age of the study subjects was 66. The subjects filled out a survey looking into the kinds of food and how much they ate over the previous month, with the survey including close to 400 different food items.
The investigators judged the quality of the diet based on Dutch recommendations for a healthy diet, and then measured on a scale from zero to 14, with 14 considered the healthiest. The best diets were those full of fruits, vegetables, nuts, whole grains, dairy and fish. Sugary drinks were minimal. The average diet got a score of 7.
The subjects also had MRI scans to ascertain the size of their brains, and information was collected about other factors which might have an affect on brain size, like blood pressure, smoking and physical activity.
The researchers adjusted the data to take into consideration the other factors and concluded that a higher diet score was linked to a larger brain size. The difference was about 2 milliliters larger for those eating the healthiest foods.
The researchers believe that 2 ml is enough to make a difference in cognitive skills.
“It is known that the risk of cognitive decline increases with advancing age. Moreover, with increasing age our brain volume decreases,” Vernooij said.
“In our population, a one-year increase in age was associated with a decrease in total brain volume of 3.66 mL, so the difference in brain volume we found is in the same order of magnitude as approximately six months’ increase in age [for those with the less healthy diet],” she explained.
The researchers point out that the study does not prove what caused the larger brain is the better diet; only that the two are associated. One scientist thinks that a healthy diet could enhance blood flow, which would be of benefit to the brain.
“We think what’s good for the heart is good for the brain. If your heart is working well and getting good blood flow to the brain, the brain will be working better,” said director of global science initiatives at the Alzheimer’s Association, James Hendrix.
“One hypothesis of Alzheimer’s is that amyloid and tau proteins build up because they’re not being cleared properly. It may be that the brain needs good blood flow to clear out those proteins,” he suggested.