G.L. Bowman, L.C. Silbert, D. Howieson, H.H. Dodge, M.G. Traber, B. Frei, J.A. Kaye, J. Shannon, and J.F. Quinn (2011) Neurology 78(4) 241-9. doi: 10.1212/WNL.0b013e3182436598. Epub 2011 Dec 28.
Objective: To examine the cross-sectional relationship between nutrient status and psychometric and imaging indices of brain health in dementia-free elders.
Methods: Thirty plasma biomarkers of diet were assayed in the Oregon Brain Aging Study cohort (n = 104). Principal component analysis constructed nutrient biomarker patterns (NBPs) and regression models assessed the relationship of these with cognitive and MRI outcomes.
Results: Mean age was 87 ± 10 years and 62% of subjects were female. Two NBPs associated with more favorable cognitive and MRI measures: one high in plasma vitamins B (B1, B2, B6, folate, and B12), C, D, and E, and another high in plasma marine ω-3 fatty acids. A third pattern characterized by high trans fat was associated with less favorable cognitive function and less total cerebral brain volume. Depression attenuated the relationship between the marine ω-3 pattern and white matter hyperintensity volume.
Conclusion: Distinct nutrient biomarker patterns detected in plasma are interpretable and account for a significant degree of variance in both cognitive function and brain volume. Objective and multivariate approaches to the study of nutrition in brain health warrant further study. These findings should be confirmed in a separate population.
This study was purely observational, and the data are cross-sectional (i.e. from a single timepoint). So the findings don't provide any direct evidence a cause-and-effect relationship between nutrition and brain aging - although they are of course consistent with this.
And although media headlines allude to Alzheimer's disease, it's also important to note that this particular study involved cognitively healthy older adults.
Having said that - this study makes an important new contribution, showing that statistically derived 'nutrient biomarker' scores (reflecting combinations of different nutrients that 'go together') were related to brain volume in this elderly population.
Brain volume shrinks with age in everyone, but in age-related cognitive impairment or dementia this loss of brain tissue is more rapid.
Of direct relevance to the current findings, a recent controlled clinical trial - i.e. a study design that can provide evidence of causality - found that supplementation with B vitamins significantly reduced brain shrinkage in older adults with mild cognitive impairment. See:
For more information and FAB comment, see the related BBC news article: