There is now one more reason to include fish in your diet.

A new study, presented Wednesday at the annual meeting of the Radiological Society of North America, links the consumption of fish to brain structure, while focusing on the risk of contracting Alzheimer's disease.

Apparently, people who eat baked or broiled fish on a weekly basis, are more likely to have a healthier brain and reduced risks of developing Mild Cognitive Impairment and Alzheimer's. The study also noted that eating fried fish did not show any increase in brain volume nor did it protect against cognitive decline.

This is the first study to establish a direct relationship between fish consumption, brain structure and Alzheimer's risk, said Cyrus Raji, 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.

The study explained that gray matter volume is crucial to brain health and shares a direct relationship with the same.

Working memory, which allows people to focus on tasks and commit information to short-term memory, is one of the most important cognitive domains, 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 researcher also noted that eating baked or broiled fish promotes stronger neurons in the brain's gray matter, thereby increasing its resistance to Alzheimer's. Apparently, volumes of the greater hippocampal, posterior cingulate and orbital frontal cortex areas, in relation to fish consumption, reduced the risk for five-year decline to MCI or Alzheimer's by almost five-fold.

The researchers explained it was important that fish be either grilled or baked, to preserve its vital Omega-3 fatty acids which are critical to actually preserving the brain. This in turn enhances blood flow to the brain thus reducing inflammation by limiting the build-up of harmful plaques that cause Alzheimer's.

Studies like this definitely justify trials that will look at Omega-3 fatty acid supplements. Having said that, I would speculate that taking supplements is no substitute for a lifetime of eating fish. We know from other studies that salmon gives the maximum amount of Omega-3 fatty acids so it is very possible, but we did not look at which fish people were eating in the study, Raji added.

The research was conducted with data from 260 cognitively normal individuals, who 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 a3D volumetric Magnetic Resonance Imaging 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 obtained was analyzed to determine if gray matter volume preservation was associated with fish consumption and whether it reduced risks 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.

The study, however, did not take into account lifestyle measures such as impact of diet and exercise on Alzheimer's, apart from the fish consumption data.