Healthy brain aging is an important part of wellness, and as the aging population expands, it is important to have a better understanding of the role of different factors on the brain, including diet.
Data from a recent study published in Frontiers in Aging Neuroscience suggest that optimal nutrition preserves cognitive function, slows the progression of aging, and reduces the incidence of debilitating diseases, such as Alzheimer disease, in healthy aging populations. Specifically, the investigators found that patients who consumed more omega-3 polyunsaturated fatty acids (O3PUFAs) performed better on cognitive flexibility tasks than patients who consumed less omega-3 fatty acids.
“This is the first report of a specific and sensitive volumetric mediation between O3PUFA levels and a particular component of the executive functions, and is shown in an at-risk population of cognitively intact older adults,” according to Marta K. Zamroziewicz, BS, Decision Neuroscience Laboratory, University of Illinois, Urbana, and colleagues. Previous research reported the benefits of omega-3 fatty acids on cognitive flexibility, or the link between cognitive flexibility and this specific region of the brain, but research was warranted to link the two.
As part of this cross-sectional study, the investigators enrolled 95 elderly adults who were not cognitively impaired (Mini-Mental State Examination [MMSE] score <26). Criteria for exclusion included diagnoses of mild cognitive impairment, dementia, and psychiatric illness within the past 3 years. Of the initial group enrolled, 40 of the 52 patients who underwent apolipoprotein E (APOE) allele genotyping carried the APOE e4 allele, and were included in the analysis. The investigators measured levels of DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), and performed neuropsychological tests and volumetric brain magnetic resonance imaging.
Overall, the study participants had a mean age of 68.80 years, and 72.5% were women. The mean O3PUFA levels were 102.30 nmol/mL in the low O3PUFA group and 216.00 nmol/mL in the high O3PUFA group. MMSE and Delis-Kaplan Executive Function System Trail Making Test cognitive flexibility scores were 28.83 and 10.30, respectively. Ms Zamroziewicz and colleagues found that only gray matter volume in the left rostral anterior cingulate cortex partially mediated O3PUFA blood levels and cognitive flexibility. They also found individual relationships between O3PUFA levels and cognitive flexibility, O3PUFA levels and left rostral anterior cingulate, and left rostral anterior cingulate and cognitive flexibility.
Previous research focused on other aspects of the brain such as memory, instead of cognitive flexibility and other executive functions such as planning, reasoning, paying attention, problem- solving, impulse control, and task switching, according to the study authors. These results add to the body of evidence pointing to a link between nutritional deficiencies and the incidence of cognitive impairment, as well as the link between cognitive impairment and degenerative neurologic disorders.
Zamroziewicz MK, Paul EJ, Rubin RD, et al. Anterior cingulate cortex mediates the relationship between O3PUFAs and executive functions in APOE e4 carriers. Front Aging Neurosci. 2015 Feb 20 [Epub ahead of print].