The new study – published in Neurology – suggests that consumption of foods that contain high levels of omega-3 fatty acids may be associated with lower blood levels of the protein, which has been implicated in the onset of Alzheimer's disease and memory problems.
Led by Dr Nikolaos Scarmeas, of Columbia University Medical Center in New York, USA, the research team noted that previous research has shown ‘increasing evidence’ that diet could play an important role “in preventing or delaying the onset of Alzheimer disease.”
Scarmeas revealed that consumption of one additional gram of omega-3 per day – above the average omega-3 consumed by people in the study – was associated with 20% to 30% lower blood beta-amyloid levels.
“We found that higher dietary omega-3 polyunsaturated fatty acid intake was associated with lower plasma beta-amyloid42 level, suggesting that the potential beneficial effects of omega-3 PUFA intake on Alzheimer’s disease and cognitive function in the literature might be at least partly explained by an amyloid-beta-related mechanism.”
Commenting on the study, Harry Rice, PhD, VP of regulatory and scientific affairs for the Global Organization for EPA and DHA Omega-3 (GOED) told NutraIngredients that whilst the research has limitations, “the results are exciting given that they provide support for what many scientists have been speculating for a number of years.”
Rice said that one the next steps would be to determine to what extent, if any, plasma beta-amyloid proteins reflect amyloid levels in the brain.
Scarmeas noted that while it is not easy to measure levels of beta-amyloid deposits in the brain, “it is relatively easy to measure the levels of beta-amyloid in the blood, which, to a certain degree, relates to the level in the brain."
The researchers examined the blood plasma levels of 1,219 people aged over 65 in a cross-sectional study that aimed to to examine the association between dietary intake of nutrientsand plasma levels of beta-amyloid. All participants were free of dementia and provided information about their diet for an average of 1.2 years before blood was tested for beta-amyloid levels.
Scarmeas and his team looked specifically at 10 nutrients, including saturated fatty acids, omega-3 and omega-6 polyunsaturated fatty acids, mono-unsaturated fatty acid, vitamin E, vitamin C, beta-carotene, vitamin B12, folate and vitamin D.
The study found participants with very high omega-3 intake had low beta-amyloid levels – with levels of beta-amyloid falling by between 20% and 30% for those people who consumed more than one additional gram of omega-3 per day (compared to the average consumption of omega-3).
Scarmeas said further research should aim to determine whether omega-3 – or other nutrients – relate to spinal fluid or brain beta-amyloid levels, or levels of other Alzheimer's disease related proteins.
Published online ahead of print, doi: 10.1212/WNL.0b013e318258f7c2
“Nutrient intake and plasma β-amyloid”
Authors: Y. Gu, N. Schupf, S.A. Cosentino, J.A. Luchsinger, N. Scarmeas