The influence of n-6 fatty acid supplemented diet on the effect of imipramine in an animal model of depression

The influence of the polyunsaturated fatty acids on body weight and anxiolytic-like behavior in female rats

Some studies have showed the benefits of polyunsaturated fatty acids (PUFAs) as a complement in weight loss diets, even though the results are hardly conclusive. Additionally, anxiety is another relevant factor that influences not only the appetite but the locomotion of the animals as well. This study evaluated the effect of a diet enriched with PUFAs in relation to body weight in an animal model of anxiety (the elevated plus maze). Female Wistar rats were allocated to one of four groups and were fed different diets for 30 days: control diet (commercial chow (Nuvilab(®)); diet enriched with fish oil; diet enriched with linseed oil, and diet enriched with soybean oil. The body weight was not influenced by the kind of diet. The group that received food enriched with linseed oil remained in the open arms for longer periods when compared with the control group. This result suggests an anxiolytic-like effect in that group.

Fatty acids intake and depressive symptomatology in a Greek sample: an epidemiological analysis

BACKGROUND

Depression is associated with an increased risk of cardiovascular disease, but the association with dietary habits is not well understood. The aim of this work was to statistically model the association of depressive symptoms with fatty acids intake in persons free of cardiovascular disease.

METHOD

A random multistage sampling, stratified by gender and age, was performed during 2001-2002. In the present work, psychological and dietary data from 453 men (19-89 years) and 400 women (18-84 years) were analyzed. Depression was assessed with the Zung's Self-rating Depression Scale (ZDRS). After a validation for the investigated population, plasma fatty acids in the form of their methyl esters were determined by gas chromatography, while dietary fatty acids were determined through a semiquantitative food frequency questionnaire and local food composition tables.

RESULTS

Women had significantly higher scores on the ZDRS as compared with men (47 ± 9 vs. 43 ± 10, p < 0.001). Multiadjusted data analysis after adjusting for age, gender, lifestyle, and dietary habits revealed that increased polyunsaturated fatty acid (PUFA) and monounsaturated fatty acid (MUFA) concentrations, and, more specifically, high concentrations of plasma total n-3 fatty acids (b ± SE: -1.9 ± 0.5, p  =  0.03), docosahexaenoic acid (-2.91 ± 1.04, p  =  0.02), eicosapentaenoic acid (-2.54 ± 0.84, p  =  0.03), α-linoleic acid (-16.8 ± 7.3, p  =  0.01), and linoleic acid (-3.97 ± 0.21, p  =  0.03), were associated with lower scores in the depression scale used.

CONCLUSION

These results indicate that increased PUFA and MUFA concentrations are associated with diminished depressive symptomatology among apparently healthy adults.

Effect of fish oil and coconut fat supplementation on depressive-type behavior and corticosterone levels of prenatally stressed male rats

Prenatal stress (PNS) during critical periods of brain development has been associated with numerous behavioral and/or mood disorders in later life. These outcomes may result from changes in the hypothalamic-pituitary-adrenal (HPA) axis activity, which, in turn, can be modulated by environmental factors, such as nutritional status. In this study, the adult male offspring of dams exposed to restraint stress during the last semester of pregnancy and fed different diets were evaluated for depressive-like behavior in the forced swimming test and for the corticosterone response to the test. Female Wistar rats were allocated to one of three groups: regular diet, diet supplemented with coconut fat or with fish oil, offered during pregnancy and lactation. When pregnancy was confirmed, they were distributed into control or stress groups. Stress consisted of restraint and bright light for 45 min, three times per day, in the last week of pregnancy. The body weight of the adult offspring submitted to PNS was lower than that of controls. In the forced swimming test, time of immobility was reduced and swimming was increased in PNS rats fed fish oil and plasma corticosterone levels immediately after the forced swimming test were lower in PNS rats fed regular diet than their control counterparts; this response was reduced in control rats whose mothers were fed fish oil and coconut fat. The present results indicate that coconut fat and fish oil influenced behavioral and hormonal responses to the forced swimming test in both control and PNS adult male rats.

Comparative study between n-6, trans and n-3 fatty acids on repeated amphetamine exposure: a possible factor for the development of mania

In the last decades, foods rich in omega-3 (ω-3) fatty acids (FA) have been replaced by omega-6 (ω-6) and trans FA, which are found in processed foods. The influence of ω-6 (soybean oil--SO), trans (hydrogenated vegetable fat--HVF) and ω-3 (fish oil--FO) fatty acids on locomotor and oxidative stress (OS) parameters were studied in an animal model of mania. Rats orally fed with SO, HVF and FO for 8 weeks received daily injections of amphetamine (AMPH--4 mg/kg/mL-ip) for the last week of oral supplementation. HVF induced hyperactivity, increased the protein carbonyl levels in the cortex and decreased the mitochondrial viability in cortex and striatum. AMPH-treatment increased the locomotion and decreased the mitochondrial viability in all groups, but its neurotoxicity was higher in the HVF group. Similarly, AMPH administration increased the protein carbonyl levels in striatum and cortex of HVF-supplemented rats. AMPH reduced the vitamin-C plasmatic levels of SO and HVF-fed rats, whereas no change was observed in the FO group. Our findings suggest that trans fatty acids increased the oxidative damage per se and exacerbated the AMPH-induced effects. The impact of trans fatty acids consumption on neuronal diseases and its consequences in brain functions must be further evaluated.

Dietary lipids and geriatric depression scale score among elders: the EPIC-Greece cohort

In a prospective epidemiological investigation aiming to identify dietary lipids potentially associated with affective state and depression, 610 healthy men and women aged 60 years or older, participating in the EPIC-Greece cohort and residing in the Attika region had dietary, sociodemographic, anthropometric, medical and lifestyle variables ascertained at enrollment. Six to 13 years later, affective state was evaluated through the 15-point geriatric depression scale (GDS) score along with cognitive function and medical variables. In multivariate linear regression analysis, while adjusting for potential confounders, GDS score was negatively associated with dietary intake of monounsaturated lipids (MUFA) and their main source, olive oil, and positively associated with intake of polyunsaturated lipids (PUFA) and one of their principal sources, seed oils. Intake of calories, total lipids, fish and seafood or saturated lipids did not exhibit significant association with GDS. Potential non-linearities were assessed by quantile multivariate regression analysis: The median GDS score was positively associated with PUFA and seed oils intake, while other lipid groups showed no appreciable associations. The 90th percentile of the GDS score (towards the high end) exhibited significant negative associations with MUFA and olive oil, weaker positive associations with PUFA and seed oils and no appreciable association with other lipid group dietary intakes. We conclude that among Attika elders, lower intake of seed oils and higher intake of olive oil prospectively predict a healthier affective state. Olive oil intake, in particular, predicts a lower chance of scoring in the highest part of the GDS.