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Flaxseed oil supplementation on severity of depression and brain-derived neurotrophic factor: a randomized, double blind placebo controlled clinical trial


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Emerging clinical studies suggest that flaxseed oil may be an effective intervention for the management of depression. The current trial was conducted to assess the effect of flaxseed oil supplementation on the Brain-derived neurotrophic factor (BDNF), and the psychological status of women with depression. Subjects of 60 depressed women aged 18–45 were randomly divided into two groups. One group was asked to consume a 1000 mg flaxseed oil capsule, twice a day for 10 weeks, while the other consumed a placebo. Serum (BDNF), Beck Depression Inventory-II (BDI-II) questionnaire, and anthropometric indices were measured before and after intervention. This study showed that serum BDNF concentration in the supplementation group increased significantly after 10-week intervention, compared with placebo (1.12 ± 0.6 pg/ml vs. 0.2 ± 0.56 pg/ml; p < .0001). Total BDI-II score was significantly lower after flaxseed oil supplementation, compared with placebo (−16.62 ± 7.03, −8.45 ± 7.8; p < .0001). The present study showed that flaxseed oil supplementation can confer a number of health benefits in depressed women, including increased serum BDNF concentrations, along with improvements in depression status.
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International Journal of Food Properties
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Flaxseed oil supplementation on severity of
depression and brain-derived neurotrophic factor:
a randomized, double blind placebo controlled
clinical trial
Fariborz Poorbaferani , Mohamamd Hoseein Rouhani , Zahra Heidari ,
Maryam Poorbaferani & Sayyed Morteza Safavi
To cite this article: Fariborz Poorbaferani , Mohamamd Hoseein Rouhani , Zahra Heidari ,
Maryam Poorbaferani & Sayyed Morteza Safavi (2020) Flaxseed oil supplementation on
severity of depression and brain-derived neurotrophic factor: a randomized, double blind
placebo controlled clinical trial, International Journal of Food Properties, 23:1, 1518-1526, DOI:
To link to this article:
Published with license by Taylor & Francis
Group, LLC.© 2020 Fariborz Poorbaferani,
Mohamamd Hoseein Rouhani, Zahra
Heidari, Maryam Poorbaferani and Sayyed
Morteza Safavi
Published online: 15 Sep 2020.
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Flaxseed oil supplementation on severity of depression and
brain-derived neurotrophic factor: a randomized, double blind
placebo controlled clinical trial
Fariborz Poorbaferani
, Mohamamd Hoseein Rouhani
, Zahra Heidari
, Maryam Poorbaferani
and Sayyed Morteza Safavi
Department of Clinical Nutrition, School of Nutrition and Food Science, Food Security Research Center, Isfahan
University of Medical Sciences, Isfahan, Iran;
Department of Community Nutrition, School of Nutrition and Food
Science, Food Security Research Center, Isfahan University of Medical Sciences, Isfahan, Iran;
Cardiac Rehabilitation
Research Centre, Cardiovascular Research Institute, Isfahan University of Medical Sciences, Isfahan, Iran;
Care Health for Institute Research Hakim Poursina, Center Research Diseases Hepatobiliary and Gastrointestinal,
Isfahan, Iran;
Committee Research’ Students Medical, Sciences Medical of University Isfahan, Isfahan, Iran
Emerging clinical studies suggest that axseed oil may be an eective
intervention for the management of depression. The current trial was con-
ducted to assess the eect of axseed oil supplementation on the Brain-
derived neurotrophic factor (BDNF), and the psychological status of women
with depression. Subjects of 60 depressed women aged 18–45 were ran-
domly divided into two groups. One group was asked to consume a 1000 mg
axseed oil capsule, twice a day for 10 weeks, while the other consumed
a placebo. Serum (BDNF), Beck Depression Inventory-II (BDI-II) questionnaire,
and anthropometric indices were measured before and after intervention.
This study showed that serum BDNF concentration in the supplementation
group increased signicantly after 10-week intervention, compared with
placebo (1.12 ± 0.6 pg/ml vs. 0.2 ± 0.56 pg/ml; p < .0001). Total BDI-II score
was signicantly lower after axseed oil supplementation, compared with
placebo (−16.62 ± 7.03, −8.45 ± 7.8; p < .0001). The present study showed
that axseed oil supplementation can confer a number of health benets in
depressed women, including increased serum BDNF concentrations, along
with improvements in depression status.
Received 19 May 2020
Revised 14 August 2020
Accepted 16 August 2020
Flaxseed oil; depression;
brain-derived neurotrophic
factor; randomized; clinical
Depression is defined as a common mood disorder, which can affect different aspects of a person’s
health, including eating, feeling, performing daily activities, and sleeping.
Depression is classified as
a mental problem, called an affective or mood disturbance.
It is estimated to affect 350 million
people worldwide, and can inflict significant economic pressure, not only on people with the disorder,
but also on families.
According to a World Health Organization (WHO) 2003 report, depression
was the third most prevalent cause of disease all over the world, and predicted that depression may be
the most prevalent cause of disease by 2030.
A recent study among the Iranian population reported
depression prevalence was 49% among women and 48% among men.
Depression has a variety of
symptoms, such as having a constantly sad mood; feeling guilty, anxious, or worthless; losing interest
or pleasure in hobbies and activities; reduced energy or increased fatigue; feeling restless; sleeplessness
or waking up in the early morning; changes in appetite and weight changes.
CONTACT Sayyed Morteza Safavi Department of Clinical Nutrition, School of Nutrition and Food
Science, Food Security Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
2020, VOL. 23, NO. 1, 1518–1526
© 2020 Fariborz Poorbaferani, Mohamamd Hoseein Rouhani, Zahra Heidari, Maryam Poorbaferani and Sayyed Morteza Safavi. Published with license by
Taylor & Francis Group, LLC.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Various factors are involved in the occurrence of depression, such as genetic, psychological or
environmental agents. One of these environmental agents is nutritional factors.
According to studies,
some nutritional supplementations such as vitamin D, zinc, selenium, and folate have a beneficial effect
on depressed patients.
Another nutritional intervention that has attracted attention from
researchers is omega-3 fatty acid. N-3 polyunsaturated fatty acids (PUFAs) are a derivative of the alpha-
linolenic acid (ALA) found in flaxseed, walnut, canola, and hemp. Among these, flaxseed has the highest
amount of ALA.
ALA is converted to docosahexaenoic acid (DHA) and eicosapentaenoic acid
(EPA), but the efficacy of this conversion is lower than 1% in humans.
In 2009, Blondeau et al.
showed that injection of ALA induced neurogenesis in the hippocampus, increased brain-derived
neurotrophic factor (BDNF) expression in vivo and in vitro, and increased neuronal cell synaptogenesis
(Nsc) in mice.
Flaxseed oil has shown promising effects in pediatric and children with bipolar
Omega-3 can affect depressive symptoms through various mechanisms, such as by
reducing pro-inflammatory cytokines, maintaining the integrity and fluidity of cell membrane (which
is important for the signaling and binding of neurotransmitters), and increasing BDNF levels.
Evidence has shown that omega-3 fatty acids have a profound effect on the nervous system. These fatty
acids affect the levels of neurotrophins, molecules, which promote neuronal growth and survival.
Among neurotrophins, BDNF level has been seen to increase in the brain with an enriched omega-3
There is a body of evidence showing that BDNF is involved in the pathology of depression. The
BDNF system enhances the function and viability of neuronal complexes, and appears to be essential for
maintaining the underlying molecular processes of cognitive function and BDNF.
Thus, BDNF may
act as an indicator of depression, and using substance that induces BDNF concentrations may play
a role as an anti-depressive adjuvant treatment.
Since there is an increasing trend of depressive disorder worldwide, finding a nutritional agent that
improves depression symptoms could offer a very effective solution. According to the researchers’
knowledge, few studies to date has assessed the effect of flaxseed oil supplementation as a major source
of ALA on depressive symptoms. Therefore, this study was designed to investigate the possible
beneficial effects of flaxseed oil supplementation among depressed subjects.
Materials and methods
Ethical approval of the study protocol
This study was performed according to the guidelines established in the Declaration of Helsinki and
the CONOSRT guidelines for clinical trial reporting,
and was approved by the Ethics Committee of
Isfahan University of Medical Sciences (IR. MUI.REC.1398.134). It was also registered at the Iranian
Registry of Clinical Trials (ID: IRCT20130903014551N3). Informed consent was obtained from all
subjects after a full explanation of the trial objectives.
Sixty depressed women were enrolled in this double-blind, randomized, controlled clinical trial from
Heshmatieh Hospital in Isfahan, Iran, between February 2019 and April 2019. Since the prevalence of
depression is higher among women and in order to increase the internal validity of present study, on
women were recruited. The suggested formula for a parallel design randomized controlled trial was
used to compute the sample size, based on α = 0.05, β = 0.15, and a standardized effect size of Δ = 0.8 in
In order to adequately assess the principal outcome, the final figure was established at 30
subjects per group.
Inclusion criteria were as follows: women between 18 and 45 years old; diagnosis of depression
according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV); and received
treatment with antidepressant medications. Subjects were excluded if they had: a history of cardio-
vascular, renal, hepatic disorders; hypertension, diabetes, or cancer; any type of cysts in the breast/
ovary of the patient and/or her family; used multivitamins and/or omega-3 supplementation during
the last year; current smoking or addiction; were pregnant or lactating; used alcohol, herbal drugs or
any other supplements/drug (except antidepressant medications) that could interfere with the study
objective after the beginning of trial. They were also later excluded if they demonstrated low
compliance (consumed <80% of prescribed supplements).
Study design
Participants were matched for age and randomly divided into the two groups of flaxseed oil and
control using the permuted block randomization method and a random number table. Randomization
was performed by a researcher who had no clinical involvement in the trial. Subjects in the treatment
group received two capsules of flaxseed oil, while control group subjects received two placebo capsules
(paraffin), which both groups were required to take twice daily for 10 weeks. Flaxseed supplements, in
the form of a 1000 mg capsule, contained only flaxseed oil. The appearance of the placebo was
indistinguishable in color, shape, size, packaging, and taste from the flaxseed capsule. Flaxseed capsule
supplements and placebos were produced by Barijessence Pharmaceutical Company, Kashan, Iran. All
participants were advised to maintain their usual diet and physical activity during the intervention
period. The subjects were reminded by phone to ensure compliance, and empty bottles of flaxseed
were returned after completion. A checklist was also used to record any possible adverse reactions.
Anthropometric measurements
Anthropometric measurements of height and body weight were made at baseline and end of study.
Height was measured by a wall-mounted stadiometer to the nearest 0.5 cm; weight was measured in
light clothing and barefoot to the nearest 0.1 kg. Body mass index (BMI) was calculated by using the
following formula: BMI = weight (kg)/height (m)
. All measurements were taken by the same person
to decrease the error rate.
Energy intake and physical activity
The energy intake of subjects was recorded using food records three times: at baseline, and in weeks 5
and 10. Food record analysis was performed using Nutritionist 4 software, modified for Iranian foods.
Participants were asked to maintain their level of physical activity during the study. To check this,
participants recorded their physical activity three times: at baseline, and in weeks 5 and 10.
A questionnaire was used with Iranian validity and reliability determined by Klishadi and colleagues.
Records of physical activity were then converted to the metabolic equivalents-hour per day (MET-h/d).
Assessment of depression status
Depression status was assessed in all study participants using a translated version of the Beck’s
Depression Inventory-II (BDI-II), which has been shown to be valid and reliable in the Persian
adult general population.
Briefly, it is a 21-item self-administered questionnaire, where the respon-
dent scores each item based on the severity of emotional experiences over the last week, ranging from 0
to 3. A score of 0 indicates that the item presented “no symptoms at all,” while 3 that indicates the item
was “very severe”. The maximum total score is 63 for a patient, and higher scores indicate greater
severity of depression. The score ranges (1–18), (18–28), (29–35), and (36–63) indicate no depressive
disorder, mild, moderate and severe depression, respectively.
Biochemical assessment
At baseline, and after 10 weeks of supplementation, 5 ml venous blood samples were collected between
8 am and 9 am after 10–12 hours of fasting. Blood samples were centrifuged at 3000 g for 10 minutes,
and the serum was isolated and frozen at −80°C until analysis. Serum level of BDNF was assessed using
the enzyme-linked immunosorbent assay (ELISA) method (Crystal day Biotech, China).
Statistical methods
Normal distributions of variables were assessed using a skewness test and Q–Q plot. All variables were
expressed as mean ± SD or number (percent), as appropriate. The baseline characteristics of participants
were analyzed between groups, using independent sample t-test. Within-group analysis was carried out
using paired t-tests, repeated measure ANOVA, or Friedman test. Analysis of covariance (ANCOVA)
was used to detect any differences between the two groups at the end of the study, adjusting for baseline
value, energy intake, physical activity and BMI. The distribution of depression categories was compared
between the two groups using Pearson’s Chi-square test. P-values less than 0.05 were considered
statistically significant. Statistical analyses were performed using IBM SPSS software version 21.
The flowchart of participants through the trial is shown in Figure 1. After assessment of 327 depressed
adult women against the inclusion and exclusion criteria, 245 participants were excluded due to not
meeting the inclusion criteria (231 participants) and refusal to participate.
Finally, 60 participants
who met the inclusion criteria were randomly assigned into the flaxseed or placebo groups. All 60
subjects successfully completed the trial and were included in the final analysis. The compliance rate
was high in both groups, based on the number of capsules returned by participants (<5%). No adverse
reaction to flaxseed supplementation or placebo was reported by any subject. Table 1 presents the
characteristics of participants in both the flaxseed and placebo groups. There is no significant
difference between the two groups in terms of age and anthropometric indices at baseline.
According to this table, weight and BMI were not significantly different after 10-week intervention
between the two groups and within each of these groups.
Energy intake and physical activity
As shown in Table 2, energy intake and physical activity were not significantly different during the
study in the intervention and control group. Also according to Table 2, physical activity and energy
intake were not significantly different between the two groups at the three assessment times (p = .51,
p = .48, respectively)
Findings in the two groups before and after treatment
After 10 weeks of intervention, a significant increase in BDNF concentration was found in the flaxseed
group (0.63 ± 0.54 vs 1.75 ± 0.68, p < .001), and this increase was significant compared to the placebo
group (1.12 ± 0.6 vs 0.2 ± 0.56; p < .0001). Also, analysis showed a significant reduction in total BDI
score in the flaxseed group (32.96 ± 9.1 vs 16.34 ± 7.42, p < .001) and a significant reduction compared
to the control group (−16.62 ± 7.03 vs −8.45 ± 7.84), as outlined in Table 3. Values remained
significant after adjusting for baseline and BMI (p < .001). Also, the decrease in the total number of
subjects across various depression categories was significant in the flaxseed group, compared to
control group (p = .009) (Table 4).
This study assessed the effect of flaxseed oil supplementation on serum concentration of BDNF and
total BDI score among depressive women. It revealed that flaxseed oil supplementation led to
improved mood status in women with depression disorder, and could increase BDNF concentration,
which is known to play an important role in mood and cognitive function.
According to studies, pathologic conditions in depression disorder (such as inflammation, low
zinc concentration and lipid peroxidation) can lead to decrease in n-3 PUFA levels.
peroxidation occurs following an inflammatory response, possibly making it responsible for reduced
n-3 PUFA levels in depressed populations.
Additionally, reductions in zinc, which acts as an anti-
oxidative factor and a cofactor for the production of alpha-linolenic acid (C18:3 n-3) are also
associated with reduced n-3 PUFA concentrations.
A meta-analysis of 14 studies revealed that
depressive patients had a lower level of EPA, DHA and n-3 PUFA.
The anti-depressive effect of
Figure 1. Flow diagram of the study.
n-3 PUFA consumption may be due to the anti-inflammatory effect of these nutrients. It can also
play a role in regulating dopaminergic and serotonergic neurotransmitters, and it is effective on the
fluidity of CNS (central nervous system) cell membranes.
Another recent meta-analysis showed
a beneficial effect of EPA supplementation or formula with the higher amount of EPA than DHA on
Table 1. General characteristics of the study participants.
Variable Flaxseed oil (N = 30) Placebo (N = 30) P-value
Age (years) 36.37 ± 5.87 37.70 ± 4.92 0.345
Weight (kg)
10 weeks
63.20 ± 11.29
63.29 ± 11.08
68.70 ± 12.71
68.46 ± 12.44
Height (m) 1.6 ± 0.06 1.6 ± 0.08 0.859
BMI (kg/m2)
10 weeks
24.69 ± 4.20
24.75 ± 4.17
26.84 ± 5.59
26.74 ± 5.44
BMI; body mass index.
p-values from independent t test
p-values from pair sample t-test
Table 2. Energy intake and physical activity.
Flaxseed oil (N = 30) Placebo (N = 30)
Time 1 Time 2 Time 3 P-value Time 1 Time 2 Time 3 P-value
0.334 1975.8065
0.155 0.389 0.485
Physical activity 1155.17
0.618 1145.65
1172.58 (107.11)
1156.45 (98.10) 0.521 0.742 0.516
Data reported based on Mean (SD)
P-values obtained from repeated measure ANOVA
Table 3. Effect of flaxseed oil supplementation on BDNF concentrations and total BDI-II score.
Flaxseed oil (N = 30) Placebo (N = 30)
Baseline End Change P-value
Baseline End Change P-value
0.63 ± 0.54 1.75 ± 0.68 1.12 ± 0.60 < 0.001 0.68 ± 0.74 0.89 ± 0.78 0.20 ± 0.56 0.055 <0.001
32.96 ± 9.1 16.34 ± 7.42 −16.62 ± 7.03 <0.001 31.29 ± 11.42 22.83 ± 9.6 −8.45 ± 7.84 <0.001 <0.001
P-value <0.05 was significant
Data reported based on Mean ± Sd
P-value obtained from paired t-test
P-value obtained from ANCOVA, adjusted for baseline, BMI, energy intake and physical activity
Abbreviations: BDI-II, Beck Depression Inventory; BDNF, brain-derived neurotrophic factor
Table 4. Number of subjects in each category of depressive disorder before and after intervention.
Flaxseed oil
Flaxseed oil p-value*
Placebo p-value* p-value**
Normal 1(3.4%) 18(62.1%) <0.0001 3(9.7%) 11(35.5%) <0.0001 0.009
Mild depression 10(34.5%) 10(34.5%) 9(29%) 13(41.9%)
Moderate depression 6(20.7%) 1(3.4%) 9(29%) 3(9.7%)
Severe depression 12(41.4%) 0(0%) 10(32.3%) 4(12.9%)
Median [Q1-Q3] 3 [2–4] 1 [1–2] 3 [2–4] 2 [1–2]
Values are number (percent); *p-value based on Friedman Test; **p-value based on Linear-by-Linear Association after intervention
the clinical symptoms of depressive disorder.
A cross-sectional study regarding n-3 PUFA intake
demonstrated that subjects with higher level of n-3 PUFA consumption had lower odds of depres-
sive disorder. However, the protective effect of n-3 PUFA intake on the incidence of depressive
symptoms could not be proven, since it may be due to folate intake, which also plays a key role in
depressive disorder.
Alpha-linolenic acid (ALA) is an omega-3 essential polyunsaturated fatty
acid from a plant-derived source, and should be provided from dietary intake. The effects of alpha
linoleic acid consumption on some disorders, such as cardiovascular disease and diabetes have been
assessed previously.
A cross-sectional study conducted among depressive subjects showed an
inverse association between serum ALA levels and depressive symptoms.
However, one other
study among healthy women revealed that RBC α-Linolenic acid concentration was inversely
associated with negative mood.
A cross-sectional study among a Japanese population found
protective properties against depression in high alpha-linolenic and linoleic acids concentrations in
Thus, n-3 PUFA may be effective for neuronal protection in depressive disorder. A study
conducted on normal mice showed that a PUFA-enriched diet with a high amount of alpha-
linolenic acid (ALA), linoleic acid, and oleic acid had an anti-depressive effect due to the increased
expression of BDNF, increased cell numbers, and synaptogenesis in the hippocampus.
showed the gene expression or activity of the brain-derived neurotrophic factors (BDNF) to be
abundant in the brain, but decreased in depressive disorder, thus suggesting anti-depressive treat-
ment could try to increase BDNF levels.
The effect of alpha-linoleic acid on increasing BDNF
levels has been shown in a recent study. Thus, it may be effective to treat depression through these
pathways, as the results of the present study are also consistent with these earlier findings.
beneficial effect of ALA on depressive symptoms has previously been shown in a study on mice. The
result of this study revealed that ALA treatment on mice led to decreased depressive behavior, in
comparison with vehicle-treated mice, as well as being effective in compensating for or repairing
neural plasticity.
Many factors contribute to induce depressive disorder (such as a deficiency of
neurotransmitters like serotonin and norepinephrine), but a growing body of evidence has shown
that neural plasticity disruption, stimulated by negative factors such as stress, can occur in
The cause of depression due to the lack of normal content of PUFA in the brain
may be due to: reduced neurotransmitters such as dopamine and serotonin; reduced expression of
Brain Derived Neurotrophic Factor (BDNF); increased inflammatory pathways; and changes in the
structure of the cell membranes.
The present study had some limitations. First, this study was conducted on a female population, so
the current findings are not generalizable to male depressed subjects. Second, plasma BDNF levels are
influenced by menstrual cycle and hormonal status of women.
This important notion was ignored in
our study and could be another limitation, which could be kept in mind when interpreting the findings.
In summary, the results of the present study indicate that consumption of flaxseed oil for 10 weeks can
increase serum BDNF concentrations and improve depressive status in depressed women. The
findings of this study may offer a new perspective for a potential intervention by dietary factors in
depression, and as such, are eagerly awaited by the patient. Further double blind randomized clinical
trials with larger sample sizes and longer follow-up periods are suggested to confirm the effects of
flaxseed oil intake on depression.
The present study is a part of MSc thesis supported by a grant from the Vice-Chancellor for Research, Isfahan University
of Medical Sciences (No.298008). The authors would like to thank all patients who kindly contributed to the study. The
authors declare no potential conflict of interest.
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... A placebo-controlled and randomized study of 25 healthy college students showed that daily drinking apple cider vinegar could reduce the risk of depression, which might be related to inhibit activation of hexosamine pathway and promote metabolism of glycine, serine and threonine [97]. Another double-blind, randomized and controlled clinical trial of 60 women with depressive disorder found that supplement with flaxseed oil twice a day for 10 weeks increased the concentration of serum BDNF and attenuated depressive symptoms [98]. In addition, a randomized controlled pilot study of 143 postpartum women showed that frequently drinking magnolia tea had protective effects against postpartum depression [99]. ...
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Depression and anxiety are severe public health problems and have attracted more and more attention from researchers of food science and nutrition. Dietary natural products and nutrients, such as fish, coffee, tea, n-3 PUFA, lycopene, and dietary fiber, could play a vital role in the prevention and management of these diseases. The potential mechanisms of action mainly include inhibiting inflammation, ameliorating oxidative stress, modulating the microbiota–gut–brain axis, suppressing hypothalamic–pituitary–adrenal axis hyperactivity, and regulating the levels of monoamine neurotransmitters. In this narrative review, we summarize the most recent advancements regarding the effects of dietary natural products and nutrients on depression and anxiety, and their underlying mechanisms are discussed. We hope that this paper can provide a better understanding of the anti-depressive and anxiolytic action of dietary natural products, and that it is also helpful for developing dietary natural products for functional food, dietary supplements, or auxiliary agents for the prevention and management of these diseases.
This trial evaluated the effects of co-supplementing Camelina sativa oil (CSO) and a prebiotic as modulators of the gut microbiota on cardiometabolic risk factors and mental health in NAFLD patients. In all, 44 subjects with NAFLD were allocated to either an intervention (20 g d-1 CSO + resistant dextrin) or a placebo (20 g d-1 CSO + maltodextrin) group and received a calorie-restricted diet (-500 kcal d-1) for 12 weeks. Fasting plasma levels of gucose, insulin, hs-CRP, endotoxin, antioxidant enzyme activity, total antioxidant capacity (TAC), malondialdehyde (MDA), 8-iso-prostaglandin F2α, and uric acid were measured at the baseline and post-intervention. The depression, anxiety and stress scale (DASS) and the general health questionnaire (GHQ) were used to assess mental health. Co-supplementing CSO and resistant dextrin significantly decreased the level of insulin concentration (-0.84 μU ml-1, p = 0.011), HOMA-IR (-0.27, p = 0.021), hs-CRP (-1.25 pg ml-1, p = 0.023), endotoxin (-3.70 EU mL-1, p = 0.001), cortisol (-2.43, p = 0.033), GHQ (-5.03, p = 0.035), DASS (-9.01, p = 0.024), and MDA (-0.54 nmol mL-1, p = 0.021) and increased the levels of TAC (0.16 mmol L-1, p = 0.032) and superoxide dismutase (106.32 U g-1 Hb, p = 0.45) in the intervention group compared with the placebo group. No significant changes were observed in the levels of other biomarkers. Co-supplementing CSO and resistant dextrin in combination with a low-calorie diet may improve metabolic risk factors and mental health in NAFLD patients.
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Epidemiological studies have suggested that there is an association between diet and mental health. The aim of the current study was to explore the association between dietary zinc intake and risk of depression, anxiety, and sleep quality distortion among female students of the Semnan University of Medical Sciences in a cross-sectional study. From January through October 2019, 142 female students were randomly selected from the Department of Nutrition and Food Science at the Semnan University of Medical Sciences by simple random sampling. Food frequency questionnaires (FFQs) were used to assess participants’ dietary intake over the past 12 months. Depression, anxiety, and sleep quality were examined by the Beck Depression Inventory-II (BDI-II), Beck Anxiety Inventory (BAI), and Pittsburgh Sleep Quality Index (PSQI), respectively. In the analysis, the crude model was adjusted for total energy intake (kcal), while the model was adjusted for energy intake (kcal), age, economic status, physical activity level, serum vitamin D level, and body mass index. Dietary zinc intake is significantly associated with depression (odds ratio (OR) (95% confidence interval (CI)): 2.34 (0.38–4.30)) and anxiety (OR (95% CI): 3.43 (2.36–4.50)), sleep disorders (OR (95% CI): 3.65 (2.16–5.13)), sleep duration (OR (95% CI): 2.62 (0.39–4.86)), and daytime dysfunction (OR (95% CI): 5.31 (2.84–7.78)) in the model, as well as sleep delay (OR (95% CI): 1.80 (1.05–2.55)) and mental quality of sleep (OR (95% CI): 1.63 (1.10–2.15)) in the crude analysis. This cross-sectional study supports the inverse association between dietary zinc intake and mood disorders, including depression and anxiety, and some indices of sleep disturbance in the Iranian female students. Further cohort or intervention studies are required to draw a firm link between dietary zinc intake and mental health.
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We conducted this meta-analysis of double-blind randomized placebo-controlled trials to estimate the efficacy of omega-3 polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), in the improvement of depression. We applied a systematic bibliographic search in PubMed and EMBASE for articles published prior to 20 December 2017. This meta-analysis was performed using RevMan 5.3 and R 3.4.3, and means and standard deviations were calculated in fixed- or random-effects models based on the results of the Q-test. A sensitivity analysis was also conducted to evaluate the stability of the results, and publication bias was evaluated by a funnel plot and Egger’s linear regression analysis. Our search resulted in 180 articles; we analyzed 26 studies, which included 2160 participants. The meta-analysis showed an overall beneficial effect of omega-3 polyunsaturated fatty acids on depression symptoms (SMD = −0.28, P = 0.004). Compared with placebo, EPA-pure (=100% EPA) and EPA-major formulations (≥60% EPA) demonstrated clinical benefits with an EPA dosage ≤1 g/d (SMD = −0.50, P = 0.003, and SMD = −1.03, P = 0.03, respectively), whereas DHA-pure and DHA-major formulations did not exhibit such benefits. Current evidence supports the finding that omega-3 PUFAs with EPA ≥ 60% at a dosage of ≤1 g/d would have beneficial effects on depression. Further studies are warranted to examine supplementation with omega-3 PUFAs for specific subgroups of subjects with inflammation, severity of depression, and the dose response for both EPA and DHA supplementation.
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Micronutrient deficiency and depression are major global health problems. Here, we first review recent empirical evidence of the association between several micronutrients—zinc, magnesium, selenium—and depression. We then present potential mechanisms of action and discuss the clinical implications for each micronutrient. Collectively, empirical evidence most strongly supports a positive association between zinc deficiency and the risk of depression and an inverse association between zinc supplementation and depressive symptoms. Less evidence is available regarding the relationship between magnesium and selenium deficiency and depression, and studies have been inconclusive. Potential mechanisms of action involve the HPA axis, glutamate homeostasis and inflammatory pathways. Findings support the importance of adequate consumption of micronutrients in the promotion of mental health, and the most common dietary sources for zinc and other micronutrients are provided. Future research is needed to prospectively investigate the association between micronutrient levels and depression as well as the safety and efficacy of micronutrient supplementation as an adjunct treatment for depression.
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Objective: depression is one of the most serious and prevalent mood disorders. Aging population is an important economic, social, and health challenge of the 21st century. The present study aimed at estimating the prevalence of depression among the Iranian elderly through meta-analysis method. Method: Studies were searched in ISI, Scopus, Pub Med, Google Scholar, and in Iranian databases including Iran Medex, Magiran, SID, and Med Lib using the following keywords: "depression", "prevalence", and "elderly". Data were analyzed using meta-analysis (random effects model). Heterogeneity among the results of the studies was examined by "I²" index. Beck, DASS-21, GHQ-28, and G DS questionnaires were used in this study, and analyses were performed using STATA Ver.11. Results: A total of 26 studies in Iran with a sample size of 5781 individuals had been found during 2001 and 2015. Prevalence of depression among Iranian elderly was estimated to be 43% (95% confidence interval (CI):30% - 55%). The findings showed that the prevalence of depression among Iranians were49% in women, 48% in men, 37% in unmarried, and 45%in the married. In addition, the prevalence of very severe, severe, moderate, and mild depression levels were estimated to be 5%, 19%, 33%, and 38% of the participants, respectively. No significant difference was observed between married and unmarried individuals. Most of Iranian elderly suffered from mild depression. Conclusion: There was high level of depression prevalence among Iranian elderly, and women were more depressed than men. So, policy makers must design and run mental health programs to decrease the prevalence of depression among Iranian elderly.
A number of studies have assessed the association between vitamin D and premenstrual syndrome (PMS) in different populations, but the findings have been inconclusive. Herein, we systematically reviewed available observational and interventional evidence to elucidate the overall relationship between vitamin D and PMS. PubMed, Cochrane Library, ScienceDirect, Scopus, Google Scholar, and ISI Web of Science databases were searched for all available articles until September 2018. The Newcastle-Ottawa quality assessment scale and Jadad scale were used to assess the quality of the observational and interventional studies, respectively. A total of 16 studies out of 196 met our inclusion criteria and were included in the final analysis. Although no significant association between serum 25(OH)D and PMS (weighted mean difference (WMD) = 3.35; 95% confidence interval, −7.80 to 1.11; p = 0.14) was indicated in observational studies, vitamin D supplementation was effective in ameliorating PMS symptoms based upon findings from interventional studies. These results add to the existing literature supporting the fact that nutrition, especially vitamin D, plays an important role in women’s health. Additional well-designed clinical trials should be considered in future research to develop firm conclusions on the efficacy of vitamin D on PMS. • KEY TEACHING POINTS • 5–8% of women experience severe PMS. • Nutrition especially vitamin D plays an important role in the women's health. • Vitamin D could exert significant clinical effects on PMS symptoms. • This is a systematic review and meta-analysis in this regard.
A number of studies have examined the association between diet and mood state, but the findings have been inconclusive. Herein, we conducted a systematic review to assess the association between different diet and mood state. PubMed, Cochrane's library, Science direct, Scopus, Google scholar and ISI web of science databases were searched for all available literature until December 2017 for studies assessing the association between diet and mood state. The Newcastle-Ottawa Scale and Jadad scale for reporting randomized clinical trials were used to assess study quality. A total of 18 studies out of 2857 met our inclusion criteria and included in our systematic review. Although there are not consistent findings between studies, it seems that DASH, vegetable-based, glycemic load-based, ketogenic and Paleo diets could improve mood more than the others. Further studies are needed to assess such relationship in a longer period to draw a firm link between diet and mood.
Major depression is a common illness that severely limits psychosocial functioning and diminishes quality of life. In 2008, WHO ranked major depression as the third cause of burden of disease worldwide and projected that the disease will rank first by 2030. 1 WHO The global burden of disease: 2004 update. World Health Organization, Geneva 2008 • Google Scholar In practice, its detection, diagnosis, and management often pose challenges for clinicians because of its various presentations, unpredictable course and prognosis, and variable response to treatment.
Objective: This article is an overview of epidemiological and treatment studies suggesting that deficits in dietary-based omega-3 polyunsaturated fatty acids may make an etiological contribution to mood disorders and that supplementation with omega-3 fatty acids may provide a therapeutic strategy. Method: Relevant published studies are detailed and considered. Results: Several epidemiological studies suggest covariation between seafood consumption and rates of mood disorders. Biological marker studies indicate deficits in omega-3 fatty acids in people with depressive disorders, while several treatment studies indicate therapeutic benefits from omega-3 supplementation. A similar contribution of omega-3 fatty acids to coronary artery disease may explain the well-described links between coronary artery disease and depression. Conclusions: Deficits in omega-3 fatty acids have been identified as a contributing factor to mood disorders and offer a potential rational treatment approach. This review identifies a number of hypotheses and studies for consideration. In particular, the authors argue for studies clarifying the efficacy of omega-3 supplementation for unipolar and bipolar depressive disorders, both as individual and augmentation treatment strategies, and for studies pursuing which omega-3 fatty acid, eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA), is likely to provide the greatest benefit.
Background: Previous research suggested that folate levels play an important role in the etiology and course of depression. However, the literature has been inconsistent with regard to differences in folate level between individuals with and without depression. The present meta-analysis synthesized the results of previous studies to examine whether individuals with depression had lower levels of folate than individuals without depression. Methods: Meta-analytic procedures were conducted in accordance with PRISMA guidelines. Studies evaluating folate levels in individuals with and without depression via red blood cell folate, serum folate, or dietary intake of folate methods were identified via PsycINFO and PubMed. Random-effects meta-analysis was conducted using Hedge's g, and moderation analysis was used for both folate measurement method and population type. Study heterogeneity was assessed with I(2) and publication bias was qualitatively assessed via funnel plot and quantitatively assessed with the trim-and-fill method and Begg's adjusted rank test. Results: We found a significant, small effect size, such that individuals with depression had lower folate levels than those without depression, Hedge's g = -0.24 (95% CI = -0.31, -0.16), p < 0.001. Study heterogeneity was high (I(2) = 84.88%), and neither folate measurement method nor population accounted for study heterogeneity. Conclusions: Individuals with depression have lower serum levels of folate and dietary folate intake than individuals without depression. Given that previous literature suggested folate supplementation improved the efficacy of traditional antidepressant medications, future research on folate supplementation in depression is warranted and clinicians may wish to consider folate supplementation for patients with depression.