DHA occurs naturally in cold-water fatty fish and seaweed. It is essential for the proper functioning of adult human brains and for the development of our nervous system and vision during the first six months of life. Omega-3 fatty acids are also part of a healthy diet that helps lower risk of heart disease.

"Additionally, we found that the greater the amount of Alzheimer's-related cognitive problems experienced in life by the patients, the lower were their liver DHA levels," Astarita said. "So we do see a connection."

Piomelli added that the results point to new diagnostic and dietary approaches to Alzheimer's: Specific blood lipid profile tests might identify at-risk persons, and dietary supplements with a chemically enhanced form of DHA may benefit early-stage patients.

"Our research isn't advocating that liver metabolism is a key to Alzheimer's," he noted. "The factors causing the disease are many and complex, but we feel this is another piece in the Alzheimer's puzzle."

Source: University of California - Irvine