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Omega-3 fatty acids may help Alzheimer’s patients

January 6, 2014

According to new research from Sweden, omega 3 fatty acids can cross the blood-brain barrier in people with Alzheimer’s disease, positively affecting markers for the disease itself and inflammation.

In the randomized controlled trial, concentrations of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) as well as disease markers in the fluid surrounding the brain were measured in 33 patients with mild Alzheimer’s disease who received either a daily omega-3 supplement (1.72 g of DHA plus 0.6 g of EPA) or a placebo for six months (1). The study results showed that the supplemented participants had higher con- centrations of DHA and EPA in their cerebrospinal fluid and blood, while no such change was seen in the placebo group. Moreover, higher levels of DHA correlated directly with a slower progression of Alzheimer’s disease and lower concentrations of inflammatory markers in the cerebrospinal fluid.

The researchers commented that earlier studies already indicated that increased intakes of omega-3 fatty acids may protect against Alzheimer’s disease. The new findings suggest that omega-3 fatty acids in dietary supplements can cross the blood-brain barrier and may be used in the treatment of Alzheimer’s disease to halt memory loss. Omega-3 fatty acids and other essential polyunsaturated fatty acids accumulate in the central nervous system (CNS) during gestation. It has been assumed that these acids are continually re- placed throughout life, but little is known about how this occurs and whether a change in diet can affect the transport of important fatty acids across the blood-brain barrier. The blood-brain barrier serves to protect the brain from harmful chemicals existing naturally in the blood, but also blocks the delivery of drug sub- stances to the brain.

Several diseases can affect the fatty acid profile of the CNS. In patients with Alzheimer’s disease, for exam- ple, previous research has observed lower than normal brain concentrations of DHA (2). Higher blood levels of DHA or other omega-3 fatty acids have been correlated with a decreased risk of cognitive loss in normal aging (3) and development of dementia (4). Researchers have long been interested in the link between Alzheimer’s disease and inflammation, but attempts to treat the disease using traditional anti-inflammatory drugs have so far failed to produce any improvements in memory function.

References

  1. Freund Levi Y. et al. Transfer of omega-3 fatty acids across the blood-brain barrier after dietary supplementation with a docosahexaenoic acid (DHA)-rich omega-3 fatty acid preparation in patients with Alzheimer's disease: the OmegAD study. Journal of Internal Medicine. Published online December 2013.
  2. Martín V. et al. Lipid alterations in lipid rafts from Alzheimer's disease human brain cortex. J Alzheimers Dis. 2010; 19:489–502.
  3. Beydoun M. A. et al. Plasma n-3 fatty acids and the risk of cognitive decline in older adults: the Atherosclerosis Risk in Communities Study. Am J Clin Nutr. 2007; 85:1103–1111.
  4. Schaefer E. J. et al. Plasma phosphatidylcholine docosahexaenoic acid content and risk of dementia and Alzheimer disease: the Framingham Heart Study. Arch Neurol. 2006; 63:1545–1550.