Effects of Varied Omega-3 Fatty Acid Supplementation on Postpartum Mental Health and the Association between Prenatal Erythrocyte Omega-3 Fatty Acid Levels and Postpartum Mental Health.

We investigated the postpartum mental health of women who had consumed perilla oil or fish oil containing various omega-3 fatty acids for 12 weeks starting in mid-pregnancy. The association between fatty acids in maternal erythrocytes and mental health risk factors was also examined. Healthy Japanese primiparas in mid-pregnancy (gestational weeks 18-25) were randomly divided into two groups and consumed approximately 2.0 g/day of omega-3 fatty acids in either perilla oil (the ALA dose was 2.4 g/day) or fish oil (the EPA + DHA dose was 1.7 g/day) for 12 weeks. Maternal mental health was assessed using the Edinburgh Postnatal Depression Scale (EPDS) as the primary measure and the Mother-to-Infant Bonding Scale (MIBS) as the secondary measure. Data from an observational study were used as a historical control. Maternal blood, cord blood, and colostrum samples were collected for fatty acid composition analysis. In addition, completers of the observational studies were enrolled in a case-control study, wherein logistic regression analysis was performed to examine the association between maternal fatty acids and EPDS score. The proportion of participants with a high EPDS score (≥9) was significantly lower in the perilla oil group (12.0%, p = 0.044) but not in the fish oil group (22.3%, p = 0.882) compared with the historical control (21.6%), while the proportions between the former groups also tended to be lower (p = 0.059). No marked effect of omega-3 fatty acid intake was observed from the MIBS results. In the case-control study of the historical control, high levels of α-linolenic acid in maternal erythrocytes were associated with an EPDS score of <9 (odds ratio of 0.23, 95% confidence interval: 0.06, 0.84, p = 0.018 for trend). The results of this study suggest that consumption of α-linolenic acid during pregnancy may stabilize postpartum mental health.

Changes in behavior and fatty acid composition induced by long-term reduction in murine Δ6-desaturation activity.

Polyunsaturated fatty acids (PUFAs), especially arachidonic acid (ARA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), play an important role in biological regulation. In our previous study using mice deficient in Δ6 desaturase (D6D), we reported that ARA is required for body growth, while DHA is necessary for functional development. In mammals, ARA and DHA are supplied directly or by synthesis from linoleic acid (LA) and α-linolenic acid (ALA). However, as desaturase enzyme activity is immature or low in newborns, and humans with minor alleles of the gene encoding desaturase, respectively, they require dietary supplementation with ARA and DHA. To investigate how the body reacts to a long-term reduction in fatty acid synthesis, we measured behavioral changes and fatty acid composition in mice heterozygous for the D6D null mutation with reduced D6D activity fed a diet containing only LA and ALA as PUFAs. During the growth-maturity period, heterozygous mice showed a slightly change in interest and curiosity compared with the wild-type group. ARA levels were decreased in the brain and liver in the heterozygous group, especially during the growth-maturity period, whereas DHA levels were decreased in the liver only in the old age period, suggesting that there are differences in the synthesis of and demand for ARA and DHA during life. For newborns, and humans with minor alleles with low desaturase activity, direct ARA intake is particularly important during the growth-maturity period, but they may need to be supplemented with DHA in the old age period. Further research is needed to determine the optimal intake and duration of these fatty acids.

Breast milk alkylglycerols sustain beige adipocytes through adipose tissue macrophages.

Prevalence of obesity among infants and children below 5 years of age is rising dramatically, and early childhood obesity is a forerunner of obesity and obesity-associated diseases in adulthood. Childhood obesity is hence one of the most serious public health challenges today. Here, we have identified a mother-to-child lipid signaling that protects from obesity. We have found that breast milk-specific lipid species, so-called alkylglycerol-type (AKG-type) ether lipids, which are absent from infant formula and adult-type diets, maintain beige adipose tissue (BeAT) in the infant and impede the transformation of BeAT into lipid-storing white adipose tissue (WAT). Breast milk AKGs are metabolized by adipose tissue macrophages (ATMs) to platelet-activating factor (PAF), which ultimately activates IL-6/STAT3 signaling in adipocytes and triggers BeAT development in the infant. Accordingly, lack of AKG intake in infancy leads to a premature loss of BeAT and increases fat accumulation. AKG signaling is specific for infants and is inactivated in adulthood. However, in obese adipose tissue, ATMs regain their ability to metabolize AKGs, which reduces obesity. In summary, AKGs are specific lipid signals of breast milk that are essential for healthy adipose tissue development.