30 November 2011

Alzheimer's Disease Risk Minimized by Eating Fish

A weekly diet of baked or broiled fish may improve brain health and reduce risk of developing mild cognitive impairment (MCI) and Alzheimer's disease. This is according to a study presented at the annual meeting of the Radiological Society of North America (RSNA).

"This is the first study to establish a direct relationship between fish consumption, brain structure and Alzheimer's risk," said Cyrus Raji, M.D., Ph.D., from the University of Pittsburgh Medical Center and the University of Pittsburgh School of Medicine. "The results showed that people who consumed baked or broiled fish at least one time per week had better preservation of gray matter volume on MRI in brain areas at risk for Alzheimer's disease."

Alzheimer's disease is an incurable, progressive brain disease that slowly destroys memory and cognitive skills. According to the National Institute on Aging, 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. People with MCI often go on to develop Alzheimer's disease.

For the study, 260 cognitively normal individuals were selected from the Cardiovascular Health Study. Information on fish consumption was gathered using the National Cancer Institute Food Frequency Questionnaire. There were 163 patients who consumed fish on a weekly basis, and the majority ate fish one to four times per week. Each patient underwent 3-D volumetric MRI of the brain. Voxel-based morphometry, a brain mapping technique that measures gray matter volume, was used to model the relationship between weekly fish consumption at baseline and brain structure 10 years later. The data were then analyzed to determine if gray matter volume preservation associated with fish consumption reduced risk for Alzheimer's disease. The study controlled for age, gender, education, race, obesity, physical activity, and the presence or absence of apolipoprotein E4 (ApoE4), a gene that increases the risk of developing Alzheimer's.

Video: The Causes and Symptoms of Alzheimer's disease

Gray matter volume is important and crucial to brain health. At high levels, the health of the brain is stable and maintained. Decreases in gray matter volume indicate that brain cells are shrinking.

According to the study, a weekly diet of fish positively positively associated with gray matter volumes in several areas of the brain. Areas such as the greater hippocampal, posterior cingulate and orbital frontal cortex had a positive effect on the grey matter volumes with relation to fish consumption. This reduces the risk for five-year decline to MCI or Alzheimer's by almost a factor of five.

"Consuming baked or broiled fish promotes stronger neurons in the brain's gray matter by making them larger and healthier," Dr. Raji said. "This simple lifestyle choice increases the brain's resistance to Alzheimer's disease and lowers risk for the disorder."

The results also showed increased levels of cognition in people who ate fish.

Video: NIH - Unraveling the Mystery of Alzheimer's Disease

"Working memory, which allows people to focus on tasks and commit information to short-term memory, is one of the most important cognitive domains," Dr. Raji said. "Working memory is destroyed by Alzheimer's disease. We found higher levels of working memory in people who ate baked or broiled fish on a weekly basis, even when accounting for other factors, such as education, age, gender and physical activity."

The study noted changes only on baked or broiled fish, eating fried fish, on the other hand, has no effect on cognitive decline. Scientists are looking into other areas such as stem cell research to find a cure for the disease.

News via: Eureaklert!