Fish Consumption and Depression (2016)

Nutritional Status of Older Adults and Health (2017)

Tryptophan & Emotional Processing (2006)

This study assessed  tryptophan & emotional processing. It explored whether tryptophan (TRP) induces cognitive changes opposite to the negative biases found in depression and characteristic of those induced by serotonergic antidepressants in healthy volunteers. Thirty eight healthy volunteers were randomised to receive 14 days double-blind intervention with TRP (1g for 3x a day) or placebo. On the final day, emotional processing was assessed using four tasks: facial expression recognition, emotion-potentiated startle, attentional probe and emotional categorisation and memory. The results showed that TRP increased the recognition of happy facial expressions and decreased the recognition of disgusted facial expressions in female, but not male, volunteers. TRP also reduced attentional vigilance towards negative words and decreased baseline startle responsivity in the females. It concludes that these findings provide evidence that TRP supplementation in women induces a positive bias in the processing of emotional material that is reminiscent of the actions of serotonergic antidepressants. This highlights a key role for serotonin in emotional processing and lends support to the use of TRP as a nutritional supplement in people with mild depression or for prevention in those at risk.

Murphy SE et al. ‘Tryptophan supplementation induces a positive bias in the processing of emotional material in healthy female volunteers’. Psychopharmacology (Berl). 2006 Jul;187(1):121-30. Epub 2006 May 4

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Vitamin D & Depression (2008)

Dutch researchers compared vitamin D levels with mood in a study of 1,282 elderly people. They found that vitamin D levels were 14% lower in those with depression. Measures of parathyroid hormone showed that this hormone was 5-33% higher in elderly individuals with depression. Depression severity was also observed to be associated with serum vitamin D levels and parathyroid hormone levels.

Vitamin D is known as the ‘sunshine vitamin’ because the primary source of it is from the action of the sun on your skin.

Hoogendijk W J G et al. ‘Depression Is Associated With Decreased 25-Hydroxyvitamin D and Increased Parathyroid Hormone Levels in Older Adults.’ Arch Gen Psychiatry. 2008;65(5):508-512

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Vitamin D linked with depression in elderly. W J G Hoogendijk et al., Arch Gen Psychiatry. 2008;65(5):508-512

Omega 3, Depression & Bipolar (2007)

This study investigated omega 3, depression and bipolar. A meta-analysis (review of studies to date) by scientists in Taiwan suggests that omega-3 fatty acids have significant antidepressant effects in patients with depression and bipolar disorder. The researchers interpret the results cautiously, however, and recommend large-scale, well-controlled trials are conducted to determine who would benefit most from fish oils, what level of dose is required and specific composition of fish oils that should be used .

Lin PY and Su KP. ‘A meta-analytic review of double-blind, placebo-controlled trials of antidepressant efficacy of omega-3 fatty acids’  J Clin Psychiatry, 2007 Jul;68(7):1056-61

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Omega 3 & Depression (2007)

The study investigated omega 3 & depression. In a small study, specific areas of the brains of deceased patients who had suffered from Major Depressive Disorder (MDD) were compared with the brains of ‘age-matched normal controls’. The omega-3 fatty acid DHA was significantly different (-22%) in the brains of the individuals with depression, compared to the normal controls. Interestingly, there was a greater difference when comparing the female brains than when comparing the male brains. This study suggests that DHA deficiency may be a contributory factor in depressive disorders, particularly in females.

McNamara RK et al., Selective deficits in the omega-3 fatty acid docosahexaenoic acid in the postmortem orbitofrontal cortex of patients with major depressive disorder. Biol Psychiatry. 2007 Jul 1;62(1):17-24.

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Chromium & Depression (2003)

This study investigated chromium & depression. In a placebo-controlled, double-blind pilot study of 15 subjects, chromium picolinate was observed to improved the moods of 70% of those taking chromium compared with 0% on placebo. Two hypothesised mechanisms of actions with relation to the observed results include 5HT2A downregulation and increased insulin sensitivity. However, due to the small sample number further studies are warranted including a greater number of participants to explore this area further.

Davidson et al., ’Effectiveness of chromium in atypical depression: a placebo-controlled trial’, Biol Psychiatry, 53(3):261-4, 2003

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Microbiome, Anxiety & Depression (2011)

This study investigated the microbiome, anxiety & depression. It is understood that there is constant communication between the gut and the brain (the gut-brain axis). In this study, mice were fed a strain of probiotic (gut bacteria) or placebo. The mice who received the probiotics showed significantly fewer stress, anxiety and depression-related behaviours than the unsupplemented mice (controls).  Not only was their behaviour different, but their levels of stress hormones were lower too. The researchers also observed altered GABA activity in the brains of the supplemented mice, suggesting a direct effect on brain chemistry.

Bravo JA, Forsythe P, Chew MV, Escaravage E, Savignac HM, Dinan TG, Bienenstock J, Cryan JF. (2011) Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. Proc Natl Acad Sci U S A. Aug 29. [Epub ahead of print]

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Breakfast & Cognition (2006)

This study examined the relationship between consumption of breakfast  & cognition. Subjects included 7,343 10th grade students from Oslo, Norway who completed a questionnaire assessing these variables. The main finding from this study was that eating breakfast regularly is associated with less mental distress and improved academic performance. The association was stronger for boys, than girls.

Lien, L., ‘Is breakfast consumption related to mental distress and academic performance in adolescents?’, Public Health Nutrition, 10(4), 422-428, 2006 July

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Depression & Processed Foods (2009)

This study investigated depression & processed foods. Eating a diet high in processed food increases the risk of depression, according to a recent study.  Data on diet among 3,500 middle-aged civil servants was compared with self reported depression five years later. Those in the ‘whole food’ (plenty of vegetables, fruit and fish) group had a lower risk of depression compared with those who had a high consumption of processed foods, the University College London team found.  The team said the study was the first to look at the UK diet and depression.

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Akbaraly, T. N., Brunner, E. J., Ferrie, J. E., Marmot, M. G., Kivimaki, M., & Singh-Manoux, A. (2009). Dietary pattern and depressive symptoms in middle age. The British journal of psychiatry : the journal of mental science, 195(5), 408–413. https://doi.org/10.1192/bjp.bp.108.058925