Fish diets have been found to lower the risk of dementia according to recent research.

People with diets rich in fish appeared to have a lower risk of dementia and Alzheimer's disease.

DHA or docosahexaenoic acid an ingredient in fish oil is a key factor that is required for the proper functioning of the central nervous system. These findings have been published in this month's issue of the Archives or Neurology.

According to lead researcher Dr. Ernst J. Schaefer, director of the Lipid Metabolism Laboratory at the Human Nutrition Research Center on Aging, "If you have a high level of DHA, a fatty acid found in fish, it reduced your risk of dementia by about half."

Schaefer added, "Just as fish is good for your heart, it's probably good for your brain as well." Mackerel, herring, lake trout, sardines, albacore tuna and salmon are high in DHA.

The research revealed people were at a 47% lower risk of developing dementia and a 39% lower risk of developing Alzheimer's.