Dietary n-6/n-3 Ratio Influences Brain Fatty Acid Composition in Adult Rats

Abstract

There is mounting evidence that diets supplemented with polyunsaturated fatty acids (PUFA) can impact brain biology and functions. This study investigated whether moderately high-fat diets differing in n-6/n-3 fatty acid ratio could impact fatty acid composition in regions of the brain linked to various psychopathologies. Adult male Sprague Dawley rats consumed isocaloric diets (35% kcal from fat) containing different ratios of linoleic acid (n-6) and alpha-linolenic acid (n-3) for 2 months. It was found that the profiles of PUFA in the prefrontal cortex, hippocampus, and hypothalamus reflected the fatty acid composition of the diet. In addition, region-specific changes in saturated fatty acids and monounsaturated fatty acids were detected in the hypothalamus, but not in the hippocampus or prefrontal cortex. This study in adult rats demonstrates that fatty acid remodeling in the brain by diet can occur within months and provides additional evidence for the suggestion that diet could impact mental health.

Use of Active Salmon-Lecithin Nanoliposomes to Increase Polyunsaturated Fatty Acid Bioavailability in Cortical Neurons and Mice

“…The overall brain FA profile in the NL group was similar to those reported in other studies [6,54,55,57]. Here, higher cortical levels of n-6 DPA, along with AA and DHA, contributed to the significant increase in PUFAs in the NL-treated group.…”

“…In this study, we chose to use young mice provided with a standard chow ad libitum during the NL treatment; no n-3 or PUFA deficiency was induced. In other studies, any intergroup difference [55,57] or age difference [6] influenced the effects of increased DHA levels in the treated group, or the effects of low levels of DHA in the brains of the control group. In our study, the significant cortical FA levels in adult mice with normal n-3 levels illustrate the possibility of enriching this brain region with PUFAs.…”

Signature of Circulating Biomarkers in Recurrent Non-Infectious Anterior Uveitis. Immunomodulatory Effects of DHA-Triglyceride. A Pilot Study

“…DHA is an essential structural constituent of cell membranes. DHA is also a precursor for the biosynthesis of a wide variety of substances, among them the series-3 prostaglandins, resolvin D1, neuroprotectin D1, maresin, and others, for the exertion of their anti-inflammatory effects [ 22 , 23 , 24 , 25 ]. Diverse experimental and epidemiological studies showed that eicosanoids derived from arachidonic acid were reduced when experimental animals [ 80 , 81 ] and patients of chronic inflammatory diseases [ 82 ] were supplemented with EPA and/or DHA.…”

“…It has been shown that docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid (ω3 PUFA), and its anti-inflammatory derivatives (series-3 prostaglandins, resolvin D1, neuroprotectin D1, maresin, etc.) exert anti-inflammatory actions in a wide variety of cells and tissues [ 22 , 23 , 24 , 25 , 26 , 27 ]. Epidemiological and experimental studies have demonstrated that the sustained intake of fish containing high amounts of ω3 PUFA benefits the cardiovascular system [ 25 ] and the neurological–neurosensory organs [ 13 , 14 , 15 , 19 , 28 , 29 ].…”

Age-Related Cognitive Decline May Be Moderated by Frequency of Specific Food Products Consumption

“…Lipids are crucial for the development of the central nervous system [ 27 ] and PUFA is an important factor for maintaining brain functioning, e.g., synaptic plasticity or regulation of neurotransmission [ 28 ]. Horman et al (2020) showed that the consumption of diets high in omega-6 PUFA, but with lower omega-3 PUFA, and conversely, changed the PUFA composition in brain structures, such as the hypothalamus, hippocampus, and prefrontal cortex [ 29 ]. Another study showed that even a short-term high-fat diet may increase the levels of corticosterone in the hippocampus and impair memory consolidation in rats [ 30 ].…”