BOSTON, MASSACHUSETTS. Docosahexaenoic acid (DHA), a major component of fish oils, is the most important fatty acid in the brain and retina and makes up more than 30% of the structural lipid (fat) in neurons. There is ample evidence that a deficiency of DHA is associated with depression, attention deficit hyperactivity disorder, and dementia. Clinical studies have shown that an increased intake of DHA may benefit patients with Alzheimer's disease and dyslexia.
Researchers at Boston University and Tufts University School of Medicine now report that they have found a clear association between low blood levels (in the phosphatidylcholine fraction of serum) of DHA and Alzheimer's disease risk. Their study involved 1188 elderly Americans (mean age of 75 years) who had blood samples drawn and analyzed for DHA in 1985. Sixteen of the participants had clinically diagnosed Alzheimer's at the time of blood sampling. The researchers noted that 11 of the 16 (69%) had DHA levels in the lower half of the DNA distribution. The remaining 1172 participants were followed for 10 years. The relationship between DHA and Alzheimer’s Disease were determined to be as follows: The researchers noted that participants with DHA levels in the lower half of the distribution had a 67% greater risk of developing Alzheimer's disease. The researchers suggest that maintaining adequate levels of DHA through the consumption of fish or dietary supplements (such as fish oil) rich in DHA may be particularly important for the elderly.
Kyle, D.J., et al. Low serum docosahexaenoic acid is a significant risk factor for Alzheimer's dementia. Lipids, Vol. 34 (suppl), 1999, p. S245