Elevated Production of Docosahexaenoic Acid in Females: Potential Molecular Mechanisms

Abstract

Observational evidence suggests that in populations consuming low levels of n-3 highly unsaturated fatty acids, women have higher blood levels of docosahexaenoic acid (DHA; 22:3n-6) as compared with men. Increased conversion of alpha-linolenic acid (ALA; 18:3n-3) to DHA by females has been confirmed in fatty acid stable isotope studies. This difference in conversion appears to be associated with estrogen and some evidence indicates that the expression of enzymes involved in synthesis of DHA from ALA, including desaturases and elongases, is elevated in females. An estrogen-associated effect may be mediated by peroxisome proliferator activated receptor-alpha (PPARalpha), as activation of this nuclear receptor increases the expression of these enzymes. However, because estrogens are weak ligands for PPARalpha, estrogen-mediated increases in PPARalpha activity likely occur through an indirect mechanism involving membrane-bound estrogen receptors and estrogen-sensitive G-proteins. The protein kinases activated by these receptors phosphorylate and increase the activity of PPARalpha, as well as phospholipase A(2) and cyclooxygenase 2 that increase the intracellular concentration of PPARalpha ligands. This review will outline current knowledge regarding elevated DHA production in females, as well as highlight interactions between estrogen signaling and PPARalpha activity that may mediate this effect.

Food for thought: how nutrition impacts cognition and emotion

“…Thus, blueberry juice significantly improved word list recall and paired associate learning in older men and women with agerelated memory decline that consumed it, relative to baseline, with paired associate learning also significantly improved relative to placebo controls. 97 A recent study 98 that measured similar cognitive tasks as those in the rodent studies, showed that freezedried blueberries (24 g/day, equivalent to one cup of fresh blueberries) for 90 days improved two measures of executive function in older adults (ages [60][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75]. Participants in the blueberry group showed significantly fewer repetition errors in the California Verbal Learning test as well as reduced switch cost on a taskswitching test across study visits, relative to controls who consumed placebo powder.…”

“…Higher AA and DHA are reported in women as compared to men, suggesting a gender difference in PUFA levels. 61 These differences could be linked to sex hormones as they differentially influence PUFA metabolism with estrogen stimulating, and testosterone inhibiting, the conversion of both omega-3 and omega-6 precursors into their respective long chain metabolites. However, whether these differences in PUFA have a role in specific brain diseases with a How diet influences cognition and emotion SJ Spencer et al…”

Effect of linseed supplementation of the gestation and lactation diets of dairy ewes on the growth performance and the intramuscular fatty acid composition of their lambs

“…Others found that feeding ewes a n-3-enriched diet in lactation increased the proportion of 18:3n-3 and their longer chain derivatives in suckling lamb muscles (Gómez-Cortés et al, 2014;Mele et al, 2014), whereas Berthelot et al (2012) did not report such effects in their earlier experiment. Some studies in human and laboratory animals suggest that the conversion of ALA into LC-PUFA homologs increases during pregnancy probably due to the agonistic effects of the female sex hormones estrogen and progesterone (Kitson et al, 2010). Similarly, de Quelen et al (2010) reported an increase in LCPUFAn-3 content in the placenta of sows fed ALA-enriched diets during pregnancy, suggesting the synthesis of LC-PUFAn-3 from dietary ALA.…”

Acción de flavonoides sobre la conversión de ácidos grasos poliinsaturados de cadena larga a partir de ácidos grasos esenciales

“…Se postula que la fosforilación y la actividad transcripcional de PPAR-α se incrementa mediante la activación de varios sistemas de protein kinasa, que son activados por receptores de estrógenos ligados a la membrana 57 , estimulando la síntesis de AGPI-CL mediante la inducción de desaturasas y elongasas 58 . En contraste, AMPK reduce la expresión génica de SREBP-1 y de sus genes diana, entre ellos ACC y ácido graso sintasa (FAS), por tanto la activación de AMPK hepática incrementaría la β-oxidación y simultáneamente reduciría la lipogénesis 59,56,13 .…”