People whoeat baked or broiled fish on a weekly basis may be improving their brain healthand reducing their risk of developing mild cognitive impairment (MCI) and Alzheimer'sdisease , according to a study presented at the annual meeting of theRadiological Society of North America (RSNA).
"This is the first study to establish a direct relationship between fishconsumption, brain structure and Alzheimer's risk," said Cyrus Raji, M.D.,Ph.D., from the University of Pittsburgh Medical Center and the University ofPittsburgh School of Medicine. "The results showed that people whoconsumed baked or broiled fish at least one time per week had betterpreservation of gray matter volume on MRI in brain areas at risk forAlzheimer's disease."
Alzheimer's disease is an incurable, progressive brain disease that slowlydestroys memory and cognitive skills. According to the National Institute onAging, as many as 5.1 million Americans may have Alzheimer's disease. In MCI,memory loss is present but to a lesser extent than in Alzheimer's disease. Peoplewith MCI often go on to develop Alzheimer's disease.
For the study, 260 cognitively normal individuals were selected from theCardiovascular Health Study. Information on fish consumption was gathered usingthe National Cancer Institute Food Frequency Questionnaire. There were 163patients who consumed fish on a weekly basis, and the majority ate fish one tofour times per week. Each patient underwent 3-D volumetric MRI of the brain.Voxel-based morphometry, a brain mapping technique that measures gray mattervolume, was used to model the relationship between weekly fish consumption atbaseline and brain structure 10 years later. The data were then analyzed todetermine if gray matter volume preservation associated with fish consumptionreduced risk for Alzheimer's disease. The study controlled for age, gender,education, race, obesity , physical activity, and thepresence or absence of apolipoprotein E4 (ApoE4), a gene that increases therisk of developing Alzheimer's.
Gray matter volume is crucial to brain health. When it remains higher, brainhealth is being maintained. Decreases in gray matter volume indicate that braincells are shrinking.
The findings showed that consumption of baked or broiled fish on a weekly basiswas positively associated with gray matter volumes in several areas of thebrain. Greater hippocampal, posterior cingulate and orbital frontal cortexvolumes in relation to fish consumption reduced the risk for five-year declineto MCI or Alzheimer's by almost five-fold.
"Consuming baked or broiled fish promotes stronger neurons in the brain'sgray matter by making them larger and healthier," Dr. Raji said."This simple lifestyle choice increases the brain's resistance toAlzheimer's disease and lowers risk for the disorder."
The results also demonstrated increased levels of cognition in people who atebaked or broiled fish.
"Working memory, which allows people to focus on tasks and commitinformation to short-term memory, is one of the most important cognitivedomains," Dr. Raji said. "Working memory is destroyed by Alzheimer'sdisease. We found higher levels of working memory in people who ate baked orbroiled fish on a weekly basis, even when accounting for other factors, such aseducation, age, gender and physical activity."
Eating fried fish, on the other hand, was not shown to increase brain volume orprotect against cognitive decline