HEALTH NEWS

Study Title:

Omega 3 Fatty Acids and Plasma Amyloid Beta

Study Abstract

OBJECTIVE:

The widely reported associations between various nutrients and cognition may occur through many biologic pathways including those of β-amyloid (Aβ). However, little is known about the possible associations of dietary factors with plasma Aβ40 or Aβ42. The aim of the current study was to evaluate the association between nutrient intake and plasma Aβ levels.

METHODS:

In this cross-sectional study, plasma Aβ40 and Aβ42 and dietary data were obtained from 1,219 cognitively healthy elderly (age >65 years), who were participants in a community-based multiethnic cohort. Information on dietary intake was obtained 1.2 years, on average, before Aβ assay. The associations of plasma Aβ40 and Aβ42 levels and dietary intake of 10 nutrients were examined using linear regression models, adjusted for age, gender, ethnicity, education, caloric intake, apolipoprotein E genotype, and recruitment wave. Nutrients examined included saturated fatty acid, monounsaturated fatty acid, ω-3 polyunsaturated fatty acid (PUFA), ω-6 PUFA, vitamin E, vitamin C, β-carotene, vitamin B(12), folate, and vitamin D.

RESULTS:

In unadjusted models that simultaneously included all nutrients, higher intake of ω-3 PUFA was associated with lower levels of Aβ40 (β = -24.7, p < 0.001) and lower levels of Aβ42 (β = -12.3, p < 0.001). In adjusted models, ω-3 PUFA remained a strong predictor of Aβ42 (β = -7.31, p = 0.02), whereas its association with Aβ40 was attenuated (β = -11.96, p = 0.06). Other nutrients were not associated with plasma Aβ levels.

CONCLUSIONS:

Our data suggest that higher dietary intake of ω-3 PUFA is associated with lower plasma levels of Aβ42, a profile linked with reduced risk of incident AD and slower cognitive decline in our cohort.

From press release:

A new study suggests that eating foods that contain omega-3 fatty acids, such as fish, chicken, salad dressing and nuts, may be associated with lower blood levels of a protein related to Alzheimer's disease and memory problems. The research is published in the May 2, 2012, online issue of Neurology®, the medical journal of the American Academy of Neurology.


"While it's not easy to measure the level of beta-amyloid deposits in the brain in this type of study, 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," said study author Nikolaos Scarmeas, MD, MS, with Columbia University Medical Center in New York and a member of the American Academy of Neurology.

For the study, 1,219 people older than age 65, free of dementia, provided information about their diet for an average of 1.2 years before their blood was tested for the beta-amyloid. Researchers 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 that the more omega-3 fatty acids a person took in, the lower their blood beta-amyloid levels. Consuming one gram of omega-3 per day (equal to approximately half a fillet of salmon per week) more than the average omega-3 consumed by people in the study is associated with 20 to 30 percent lower blood beta-amyloid levels.

Other nutrients were not associated with plasma beta-amyloid levels. The results stayed the same after adjusting for age, education, gender, ethnicity, amount of calories consumed and whether a participant had the APOE gene, a risk factor for Alzheimer's disease.

"Determining through further research whether omega-3 fatty acids or other nutrients relate to spinal fluid or brain beta-amyloid levels or levels of other Alzheimer's disease related proteins can strengthen our confidence on beneficial effects of parts of our diet in preventing dementia," said Scarmeas.

Study Information

Gu Y, Schupf N, Cosentino SA, Luchsinger JA, Scarmeas N.
Nutrient intake and plasma β-amyloid
Neurology.
2012 May
Taub Institute for Research in Alzheimer's Disease and the Aging Brain