Lack of an association of depression with n-3 polyunsaturated fatty acids in adipose tissue and serum phospholipids in healthy adults

Statement on additional scientific evidence in relation to the essential composition of total diet replacement for weight control

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to revise the Opinion on the essential composition of total diet replacements for weight control (TDRs) regarding the minimum content of linoleic acid (LA) and alpha-linolenic acid (ALA) and the maximum content of magnesium (Mg). Through a comprehensive literature search, human studies were retrieved reporting on LA and ALA concentrations in adipose tissue (AT), on weight loss and gallstone formation following TDR consumption and on diarrhoea after supplemental Mg intake. The distribution of the amount of LA and ALA release from AT during weight loss when consuming TDRs was estimated using statistical simulations. Using the fifth percentile, the coverage of the adequate intake (AI) for both FA was estimated. For the risk of developing diarrhoea when consuming TDRs with an Mg content of 350 mg/day, four cross-over studies using 360-368 mg Mg/day were reviewed. The Panel concludes that (1) there is no need to add LA to TDRs, as the amount released from AT during weight loss when consuming TDRs is sufficient to cover the AI for LA; (2) a minimum of 0.8 g/day ALA is needed in TDRs in order to meet the AI for ALA; (3) the minimum fat content of TDRs of 20 g/day as derived in the Panel's previous opinion is proposed to be maintained until the availability of further evidence, given the considerable uncertainty as to the amount of fat required for reducing the risk of gallstone formation; and (4) the likelihood that Mg-induced diarrhoea occurs at a severity that may be considered of concern for overweight and obese individuals consuming TDRs is low when the total maximum Mg content in TDRs is 350 mg/day.

Association between erythrocyte levels of n-3 polyunsaturated fatty acids and depression in postmenopausal women using or not using hormone therapy

OBJECTIVE

Epidemiologic and clinical studies have suggested that hormone therapy (HT) and n-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), exert antidepressant effects through regulation of the serotonergic pathway. The present study was conducted to evaluate the hypothesis that erythrocyte levels of n-3 PUFAs and depression were negatively associated in postmenopausal women, particularly those using HT.

METHODS

A total of 214 postmenopausal women were divided into groups defined by depression and HT status. Depression was defined as a Beck Depression Inventory score of at least 14, and the types and durations of HT were obtained from medical records.

RESULTS

Erythrocyte levels of EPA, docosapentaenoic acid (DPA), DHA, omega-3 index (sum of EPA + DHA), total n-3 PUFA, and arachidonic acid were significantly higher in women using HT than in those not using HT. There were significant negative correlations between depression and erythrocyte levels of alpha-linolenic acid (r = -0.310), DPA (r = -0.272), DHA (r = -0.209), and total n-3 PUFA (r = -0.234) in women using HT. Multivariate-adjusted logistic regression analysis also showed that depression was negatively associated with the erythrocyte levels of alpha-linolenic acid (P for trend = 0.018), DPA (P for trend = 0.014), and DHA (P for trend = 0.036), only in women using HT.

CONCLUSIONS

Negative associations between erythrocyte levels of n-3 PUFAs and depression were found in Korean postmenopausal women using HT but not in those not using HT, suggesting a synergistic effect of HT and n-3 PUFAs on depression.

Associations of the Ratios of n-3 to n-6 Dietary Fatty Acids With Longitudinal Changes in Depressive Symptoms Among US Women

In the present study, we examined longitudinal changes in self-reported depressive symptoms (and related domains) in relation to baseline intakes of n-3 fatty acids (absolute and relative to n-6 fatty acids). Sex-specific associations were evaluated in a prospective cohort of adults (n = 2,053) from Baltimore, Maryland, who were 30-64 years of age at baseline and were followed for a mean of 4.65 (standard deviation, 0.93) years (2004-2013). Using mean intakes of n-3 and n-6 fatty acids reported on two 24-hour dietary recalls, we estimated the ratios of n-3 to n-6 fatty acids for both highly unsaturated fatty acids (≥20 carbon atoms) (HUFAs) and polyunsaturated fatty acids (≥18 carbon atoms) (PUFAs). Outcomes included total and domain-specific scores on the 20-item Center for Epidemiologic Studies-Depression scale. Based on mixed-effects regression models, among women, both higher n-3 HUFA:n-6 PUFA and n-3 PUFA:n-6 PUFA ratios were associated with a slower rate of increase in total Center for Epidemiologic Studies-Depression scores over time. Higher n-3 HUFA:n-6 HUFA ratios were associated with slower increases in somatic complaints in men, whereas among women, higher n-3 HUFA:n-6 PUFA and n-3 PUFA:n-6 PUFA ratios were both linked to putative longitudinal improvement in positive affect over time. Among US adults, n-3:n-6 dietary fatty acid ratio was associated with longitudinal changes in depressive symptoms, with a higher ratio linked to a slower increase in depressive symptoms over time, particularly among women.

Omega-3 fatty acids and depression: scientific evidence and biological mechanisms

The changing of omega-6/omega-3 polyunsaturated fatty acids (PUFA) in the food supply of Western societies occurred over the last 150 years is thought to promote the pathogenesis of many inflammatory-related diseases, including depressive disorders. Several epidemiological studies reported a significant inverse correlation between intake of oily fish and depression or bipolar disorders. Studies conducted specifically on the association between omega-3 intake and depression reported contrasting results, suggesting that the preventive role of omega-3 PUFA may depend also on other factors, such as overall diet quality and the social environment. Accordingly, tertiary prevention with omega-3 PUFA supplement in depressed patients has reached greater effectiveness during the last recent years, although definitive statements on their use in depression therapy cannot be yet freely asserted. Among the biological properties of omega-3 PUFA, their anti-inflammatory effects and their important role on the structural changing of the brain should be taken into account to better understand the possible pathway through which they can be effective both in preventing or treating depression. However, the problem of how to correct the inadequate supply of omega-3 PUFA in the Westernized countries' diet is a priority in order to set food and health policies and also dietary recommendations for individuals and population groups.

Erythrocyte n-3 polyunsaturated fatty acid and seafood intake decrease the risk of depression: case-control study in Korea

BACKGROUND/AIMS

Low intake or tissue levels of n-3 polyunsaturated fatty acids (PUFA) have been associated with an increased risk of depression, but some studies do not support the association. The purpose of the present study was to evaluate the hypothesis that erythrocyte levels of n-3 PUFA and intake of seafood are negatively associated with the risk of depression in Koreans.

METHODS

We investigated 80 patients diagnosed with a score ≥25 on the Center for Epidemiological Studies Depression Scale, Korean version, and confirmed by a psychiatrist. Eighty-eight controls without a chronic disease were matched to the cases for age and sex.

RESULTS

Multivariate-adjusted regression analysis showed that the risk of depression was significantly and negatively associated with erythrocyte levels of 20:5 n-3, 22:6 n-3, 16:0 and 18:0, but positively associated with erythrocyte levels of 18:2t and 16:1 after adjusting for confounding factors. In addition, the risk of depression was negatively associated with the intake of energy, carbohydrate, seafood and grains, but positively with the intake of fat and meat after adjustment for confounding factors.

CONCLUSIONS

The risk of depression could be decreased with increased erythrocyte levels of n-3 PUFA and saturated fatty acids, as well as seafood intake, but decreased erythrocyte levels of trans fatty acids in Koreans.

Red blood cell fatty acids are associated with depression in a case-control study of adolescents

INTRODUCTION

Epidemiological studies suggest that reduced intakes and/or blood levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are associated with increased risk for depression in adults, but data on adolescents are scarce. The objective of this study was to determine whether red blood cell (RBC) levels of EPA+DHA (the omega-3 index) and/or the overall RBC fatty acid profile differ between depressed adolescents (cases) and non-depressed adolescents (controls).

PATIENTS AND METHODS

We measured the RBC fatty acid composition of cases admitted to the hospital for depression (n=150) and compared it to that of controls (n=161).

RESULTS

Cases and controls had similar ages, gender proportions, and body mass index (BMI) distributions, but there was a significant difference in racial/ethnic composition due to differences in recruitment sites. The unadjusted odds ratio for case status was 0.72 (95% CI; 0.55-0.95) for a 1% absolute increase in the omega-3 index. A multivariable logistic regression model was used to determine which fatty acids were useful in classifying cases and controls; BMI, age, gender, and race/ethnicity were forced into the model. Seven fatty acids were selected (DHA, myristic, stearic, oleic, trans linoleic, trans palmitoleic, and alpha-linolenic acids) to optimize the model fit to the data. In the adjusted model, the odds ratio was 0.67 (95% CI; 0.49-0.93) for a 1 SD increase in DHA. Adding the seven fatty acid profile to the basic model increased the area under the ROC curve by 12.6% (7.5%-17.6%).

DISCUSSION AND CONCLUSION

These findings support the hypothesis that adolescent depression is associated with a perturbed RBC fatty acid pattern which includes a reduced omega-3 index. Intervention studies with EPA and DHA should be conducted in this vulnerable population for which few, safe therapeutic options currently exist.

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.

Type 1 diabetes mellitus and major depressive disorder: evidence for a biological link

AIMS/HYPOTHESIS

A growing body of research suggests that the prevalence of major depressive disorder (MDD) in children and youth with type 1 diabetes mellitus is significantly higher than that of youth without type 1 diabetes and is associated with increased illness severity. The objective of this article is to review the current literature on the pathophysiology of these two common diseases with respect to potential areas of overlapping biological dysfunction.

METHODS

A search of English language articles published between 1966 and 2010 was conducted and augmented with manual review of reference lists from the identified publications.

RESULTS

The evidence suggests plausible mechanisms whereby a biological relationship between type 1 diabetes and MDD may exist. These include the effects of circulating cytokines associated with autoimmune diabetes, the direct impact of insulin deficiency on neurogenesis/neurotransmitter metabolism, the effects of the chronic hyperglycaemic state, occurrence of iatrogenic hypoglycaemia and the impact of basal hyperactivity of the hypothalamic-pituitary-adrenal axis.

CONCLUSIONS/INTERPRETATION

Shared biological vulnerabilities may be implicated in the comorbidity of type 1 diabetes and MDD. Further research is warranted to determine the magnitude of associations and confirm their observation in clinical populations.

Gluteal adipose-tissue polyunsaturated fatty-acids profiles and depressive symptoms in obese adults with obstructive sleep apnea hypopnea syndrome: a cross-sectional study

Biomarkers of Polyunsaturated Fatty Acids (PUFAs) have been related to depressive symptoms in healthy adults. It is also known that depression is high prevalent in Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS) and obesity. The aim of our study was to examine a possible association between PUFAs of the n-6 and n-3 families and depressive symptoms in obese OSAHS patients. Sixty three patients with OSAHS based on overnight attended polysomnography were included. Gluteal adipose tissue biopsies were performed in all participants. Fatty acids were analyzed by gas chromatography. Depressive symptoms were assessed by the Zung Self-rating Depression Scale. The majority of participants had grade II obesity (BMI: 36.2±4.3 kg/m(2)) and moderate to severe OSAHS. Mild depressive symptoms were found to affect 27.8% of the studied patients. No link between symptoms of depression and individual n-6 and/or n-3 PUFAs of gluteal adipose tissue was detected. However, multiple linear regression analysis showed a positive correlation between depressive symptoms and 20:3n-6/18:3n-6 ratio, and a negative association with age and n-6/n-3 ratio. The possible influence of OSAHS and obesity in depression development and the quiescent nature of gluteal adipose tissue may account for the absence of any significant relations between n-6 and/or n-3 PUFAs and depressive symptoms in our sample. The positive relationship between symptoms of depression and the particular fatty acid ratio probably indicates an increase in prostaglandins family although this needs further research.

Fatty acids measured in plasma and erythrocyte-membrane phospholipids and derived by food-frequency questionnaire and the risk of new-onset type 2 diabetes: a pilot study in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk cohort

BACKGROUND

Epidemiologic evidence for the association between types of fatty acid and risk of type 2 diabetes is inconsistent. This may in part be due to the limitations of fatty acid measurement methods.

OBJECTIVE

The objective was to use 3 different measures of fatty acid to estimate the prospective association between fatty acid composition and development of incident diabetes.

DESIGN

We analyzed 199 cases of clinically incident diabetes and 184 noncases aged 40-79 y at baseline in the EPIC (European Prospective Investigation into Cancer and Nutrition)-Norfolk study. Fatty acids were derived from a food-frequency questionnaire (FFQ) and measured in plasma phospholipid (P-FA) and erythrocyte-membrane phospholipid (Ery-FA) fractions by gas chromatography.

RESULTS

There were stronger associations with diabetes risk with the use of objectively measured fatty acids (P-FA and Ery-FA) than with the FFQ in analyses adjusted for age, sex, and potential confounders. Positive associations with diabetes were greater in magnitude with the use of P-FA than with Ery-FA (highest:lowest tertiles): for example, the palmitic acid odds ratios (ORs) were 2.47 (95% CI: 1.37, 4.46) and 1.96 (95% CI: 1.10, 3.49), respectively. Inverse associations with diabetes were also stronger with the use of P-FA than with Ery-FA: for example, the OR for linoleic acid was 0.50 (95% CI: 0.28, 0.91) compared with 0.77 (95% CI: 0.43, 1.37), respectively.

CONCLUSIONS

The objective measurement of fatty acids with the use of either P-FA or Ery-FA identifies important associations with diabetes incidence that may be missed when assessed by FFQ. Fatty acids measured in P-FA appear to be more strongly associated with diabetes incidence. These findings endorse the use of objective measurement of fatty acids for nutritional-epidemiologic studies, and the apparently stronger findings for the plasma fraction should be confirmed in larger studies and in different populations.

A meta-analytic review of polyunsaturated fatty acid compositions in patients with depression

BACKGROUND

On the basis of evidence from studies showing the antidepressant effects of omega-3 polyunsaturated fatty acids and the inverse relation between fish consumption and the prevalence of depression, the phospholipid hypothesis seems promising in ascertaining the etiology and treatment of depression. Although several studies have shown lower levels of omega-3 (n-3) polyunsaturated fatty acids in depressive patients, the results of individual polyunsaturated fatty acids, including docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and the omega-6 (n-6) polyunsaturated fatty acid arachidonic acid (AA), were inconsistent.

METHODS

We conducted the meta-analyses of 14 studies comparing the levels of polyunsaturated fatty acids between depressive patients and control subjects. The effect size of each study was synthesized by using a random effects model.

RESULTS

Compared with control subjects, the levels of EPA, DHA, and total n-3 polyunsaturated fatty acids were significantly lower in depressive patients. There was no significant change in AA or total n-6 polyunsaturated fatty acids.

CONCLUSIONS

The results showed lower levels of EPA, DHA, and total n-3 polyunsaturated fatty acids in patients with depression, thus implying that n-3 polyunsaturated fatty acids play a role in the pathogenesis of depression. Our findings provide further support to the phospholipid hypothesis of depression and a rationale for using n-3 polyunsaturated fatty acids as an alternative treatment for depression. With these results, future studies examining specific roles of DHA and EPA in different clusters of depressive symptoms are warranted.

Fish consumption and omega-3 polyunsaturated fatty acids in relation to depressive episodes: a cross-sectional analysis

High fish consumption and omega-3 polyunsaturated fatty acid (PUFA) intake are suggested to benefit mental well-being but the current evidence is conflicting. Our aim was to evaluate whether a higher level of fish consumption, a higher intake of omega-3 PUFAs, and a higher serum concentration of omega-3 PUFAs link to a lower 12-month prevalence of depressive episodes.We used data from the nationwide Health 2000 Survey (n = 5492) and the Fishermen Study on Finnish professional fishermen and their family members (n = 1265). Data were based on questionnaires, interviews, health examinations, and blood samples. Depressive episodes were assessed with the M-CIDI (the Munich version of the Composite International Diagnostic Interview) and a self-report of two CIDI probe questions, respectively. Fish consumption was measured by a food frequency questionnaire (g/day) and independent frequency questions (times/month). Dietary intake (g/day) and serum concentrations (% from fatty acids) of PUFAs were determined. Fish consumption was associated with prevalence of depressive episodes in men but not in women. The prevalence of depressive episodes decreased from 9% to 5% across the quartiles of fish consumption (g/day) in men of the Health 2000 Survey (p for linear trend = 0.01), and from17% to 3% across the quartiles of fish consumption (times/month) in men of the Fishermen Study (p for linear trend = 0.05). This association was modified by lifestyle; in the Health 2000 Survey a higher level of fish consumption was related to a lower prevalence of depressive episodes in men who consumed the most alcohol, were occasional or former smokers, or had intermediate physical activity. The associations between depressive episodes and the intake or serum concentrations of omega-3 PUFAs were not consistent.In men, fish consumption appears as a surrogate for underlying but unidentified lifestyle factors that protect against depression.

FADS1 FADS2 gene variants modify the association between fish intake and the docosahexaenoic acid proportions in human milk

BACKGROUND

The genes encoding Delta(5)- and Delta(6)-desaturases (FADS1 FADS2 gene cluster) were reported to be associated with n-3 (omega-3) and n-6 (omega-6) fatty acid proportions in human plasma, tissues, and milk. Docosahexaenoic acid (DHA) can be supplied especially by dietary fish or fish oil and synthesized from alpha-linolenic acid through a pathway involving these desaturases.

OBJECTIVE

We evaluated whether FADS gene variants modify the effect of maternal fish and fish-oil intake on plasma and milk DHA proportions.

DESIGN

FADS1 rs174561, FADS2 rs174575, and intergenic rs3834458 single nucleotide polymorphisms were genotyped in 309 women from the KOALA Birth Cohort Study in The Netherlands. Plasma was collected at 36 wk of pregnancy, and milk was collected at 1 mo postpartum. Fish and fish-oil intake was assessed by using a food-frequency questionnaire at 34 wk of pregnancy and updated for the week of milk collection. Gene-diet interactions were tested by linear regression analysis.

RESULTS

DHA proportions were lower in women homozygous for the minor allele than in women who were homozygous for the major allele (DHA proportions in plasma phospholipids: P < 0.01; DHA proportions in milk: P < 0.05). Fish intake ranged from 0 to 2.5 portions of fatty fish/wk, and 12 women took fish-oil supplements during pregnancy. DHA proportions in plasma phospholipids increased with increasing fish and fish-oil intake, irrespective of the genotype. DHA proportions in milk increased only with fish and fish-oil intake in the major-allele carriers.

CONCLUSION

Lower proportions of DHA in milk from women who were homozygous for the minor allele could not be compensated for by increasing fish and fish-oil intake, possibly because of limited incorporation into milk.

Fish consumption and polyunsaturated fatty acids in relation to psychological distress

BACKGROUND

It has been suggested that high fish consumption improves mental well-being. The aim of this study was to assess whether high fish consumption or omega-3 polyunsaturated fatty acid (PUFA) intake was associated with reduced self-reported psychological distress.

METHODS

We used three cross-sectional data sets, the nationwide Health 2000 Survey (n = 5840), the Fishermen Study on Finnish fishermen and their family members (n = 1282) and the Finntwin16 Study on young adults (n = 4986). Data were based on self-administered questionnaires, interviews, health examinations and blood samples. Psychological distress was measured using the 12-item and 21-item General Health Questionnaires (GHQs). Fish consumption was measured by a food frequency questionnaire (FFQ, g/day) and independent frequency questions (times/month). Dietary intake (g/day) and serum concentrations (% from fatty acids) of PUFAs were determined. Relationships were analysed using regression analysis.

RESULTS

Regardless of the measure, fish consumption and omega-3 PUFA dietary intake were not associated with distress in any of the data sets. In contrast to the hypothesis, high serum docosahexaenoic acid was associated with high distress in the Fisherman Study men. Some non-linear associations were detected between serum omega-3 PUFAs or fish consumption (times/month) and distress. In the Fishermen Study, the associations were modified by alcohol consumption, smoking and physical activity.

CONCLUSIONS

Our results do not support the hypothesis that fish consumption or omega-3 PUFA intake are associated with reduced psychological distress in the general population or in a population with high fish consumption.

Paraoxonase 1 R/Q alleles are associated with differential accumulation of saturated versus 20:5n3 fatty acid in human adipose tissue

Serum paraoxonase 1 (PON1) function has been associated with human cardiovascular disease. The projected mechanism postulates interaction of PON1 with lipoproteins and insulin signaling resulting in alterations in lipid homeostasis. Recently, PON2 was shown to directly regulate triglyceride accumulation in macrophages and PON1 was detected in the interstitial space of adipocytes. The aims of the present study were a) to examine the relationship of the PON1 function with serum parameters related to lipid homeostasis, and b) to examine a possible role of PON1 in the regulation of lipid composition in the human adipose tissue. Two important genetic variations with functional impact on PON1 activity in humans are the Q192R and the L55M. The present study evaluated the impact of the Q192R and the L55M polymorphisms in a cross-section of the population on the island of Crete, as regards to PON1 activity, plasma lipids/lipoproteins, parameters of the metabolic syndrome, and the fatty acid composition of the adipose tissue. We detected a significant association of the polymorphisms with blood pressure, fasting blood glucose, triglycerides, apolipoprotein B, serum iron, and homocysteine. Furthermore, a novel function is suggested for PON1 on the fatty acid composition in the adipose tissue through the positive association of the R allele with saturated fatty acid and of the Q allele with 20:5n3 fatty acid deposition.

Nutrition, mood and behaviour: a review

OBJECTIVE

To conduct a critical review of recent empirical research regarding mood, behaviour and nutrition factors including essential fatty acids, macronutrients, micronutrients and food additives.

METHOD

A literature search of databases Medline, PsycInfo, CINAHL and Embase up to October 2008. The search emphasised empirical research published in the last 10 years and also included older literature. Studies in both adults and children were addressed.

RESULTS

Research into omega-3 fatty acids has been substantial but evidence for their potential in treating mood and behaviour is modest. In comparison, there has been much less research into carbohydrate and protein intakes and little evidence for their ability to influence mood and behaviour. Recent trials with food additives suggest their removal from the diet may benefit susceptible children with hyperactivity disorders. Micronutrient supplementation appears to improve mood only in those who were initially deficient in micronutrients.

CONCLUSIONS

More stringent research designs such as longitudinal studies and the use of biologically inert placebos within randomised controlled trials are needed before supplemental use of omega-3 fatty acids to treat disorders of mood and behaviour can be recommended. Caution is advised regarding the indiscriminate use of diets free of artificial food additives in managing hyperactivity disorders, as they may place an undue burden on individuals and their families. Should omega-3 fatty acid supplementation or the elimination of certain food additives be established as effective, they may provide cost-effective, accessible and well-tolerated adjuncts to standard psychiatric treatments for mood and behavioural disturbances.

Long-chain n-3 fatty acid levels in baseline serum phospholipids do not predict later occurrence of depressive episodes: a nested case-control study within a cohort of middle-aged French men and women

The goal of this study was to seek the relations between baseline n-3 PUFA status and the later occurrence of depressive episodes in a French cohort of middle-aged men and women, the SU.VI.MAX study. A nested case-control study was designed within the cohort: cases with at least two depressive episodes during the 8-year follow-up were paired to non-depressed controls, antidepressant prescriptions being taken as markers of depressive episodes. The fatty acid profiles of baseline serum phospholipids have been determined. Results were analyzed using logistic regression and principal component analysis, taking into account depression history and demographic and lifestyle confounders. There was no consistent association of depression risk with any serum fatty acid, and in particular there was no association of depression risk with the long-chain n-3 PUFA eicosapentaenoic, docosapentaenoic and docosahexaenoic acids. This study does not support the hypothesis of a predictive value of n-3 PUFA status for depression in population settings.