top of page

Food and Mood: Can Diet Affect How We Feel?

Given the impact that poor mental health has on us as individuals and as a society, there has been much research regarding the potential impact of diet on altering our mood.

Now, I’m sure most of us can agree that when we eat better, we feel better, but this goes beyond that. Asking whether our diet can play either a protective role or be a risk in developing mental health conditions and further, if changing our diet can work as a complementary therapy in mental health conditions, particularly depression.

Well, the evidence is very promising. Not only for depression, but also general low mood. Researchers have looked at the impact of individual nutrients or components of food, dietary patterns, inflammation and gut health. The evidence in its totality speaks to incorporating a varied, wholefood diet, rich in fruits, vegetables, whole grains, good fats and lean proteins but also reducing added sugars, saturated fats and processed foods.

It’s a growing area of interest and has been personally a rewarding and beneficial consideration in my practice thus far. So, let’s have a look at why diet many be so useful in improving our mood…


This study is definitely one of the most exciting studies regarding diet and mental health at the moment. The study, published in 2017, was a randomised controlled trial looking to see whether what we eat could improve depressive symptoms.

All participants had been diagnosed with major depression. The participants were split into two groups. The first group received dietary intervention with a dietitian and advised to follow a modified Mediterranean diet (rich in whole grains, fruit and vegetables, good fats and reducing discretionary foods). The second group were in what is called the ‘control’ group, who participated in social support meetings at the same frequency as the other group saw the dietitian.

The study found that after 12 weeks, the dietary intervention group had significant changes in their depressive symptoms compared to the control. So much so, that 32% went into clinical remission, which is huge. Moreover, results were still seen in those who did not completely adhere to the diet, still finding improvement in their symptoms. All participants remained on any prescriptive medications, this is important to note too.

A similar 3 week study in young adults found improvement with depressive symptoms with diet improvement, and a recent systematic review also advocates for similar dietary intervention to aid in improving our mental health.

Moreover, a 2016 study found that increased fruit and vegetable consumption was predictive of increased happiness, satisfaction and well-being across over 12,000 Australians!

Specific Nutrients

Generally speaking, a poor diet will be lacking in many essential nutrients. These nutrients play an important role in the optimal functioning of our body, and so, the idea that having an inadequacy of any of these may impact our mental health, doesn’t seem outrageous.

A note about supplementation: when it comes to evidence regarding nutrients or foods like this, it doesn’t always translate to supplement use. Always consult a health professional if you are seeking advice regarding supplementation as it may not only not be useful for your goals, but could be detrimental to your health if it interferes with medications, health conditions or just has horrible side effects.


Antioxidants fight free radicals in our body. Free radicals can cause harm to our cells when too high in our body, so the theory is that a diet rich in antioxidants may be protecting us from depression, along with many other health conditions.

Where to find them: They are easily found in fruits, vegetables, nuts, seeds and whole grains, for example. Some you may have heard of before are vitamin C, zinc, selenium, vitamin E and lycopene.

B vitamins, particularly folate.

Folate is a vitamin required for DNA synthesis, cell division and is important for the healthy maintenance of our brain throughout life. Folate and all other B vitamins, are required for deriving energy from food and to generate neurochemicals (chemicals related to our nervous system function, also impacting our thoughts and emotion) and signalling molecules.

Symptoms of deficiency in the B vitamins include irritability and depression, however, this is particularly strong for folate, and visa versa, those with depression are more likely have lower levels of folate. Additionally, those with low folate levels have also been found to be more likely to have low serotonin levels, also called the ‘happy hormone’, involved in mood regulation.

Where you’ll find them: wholegrains, dark leafy greens, fortified cereals, fruit and vegetables, legumes and B12 will only be found in animal products (or supplementation for vegans), though some of the other B vitamins will be there too. Also, high alcohol consumption will reduce your absorption of folate.


Zinc is an essential mineral, and understandably so, over 300 enzymes rely on this guy to ensure bodily functions including DNA and protein production and is required for optimal immune and hormone function. Part of the role of zinc also includes Individuals with depression have been found to have lower levels of zinc, than those without.

One theory is that the relationship between zinc and a chemical called BDNF (brain-derived neurotrophic factor), which helps by promoting brain development and recovery. A deficiency in zinc, may impact BDNF levels and so, result in depressive symptoms (this is still being understood).

When in times of stress or trauma, we don’t hold on to zinc so well, either.

Where you’ll find it: oysters, lean meat, legumes, seeds, egg yolk, wholegrains and bran.


Magnesium is another essential mineral involved in over 300 different functions in the body, including: nerve and muscle function, energy production, bone health, management of stress, and many processes in the brain which are related to the development of depression. Like many of the other nutrients mentioned, low levels of magnesium have been associated with depression and anxiety.

Where you’ll find it: Pumpkin seeds, dark chocolate/cacao, almonds, bananas, wholegrains, legumes.


Selenium plays an important role in our reproductive, thyroid and immune health. It is key in many antioxidant pathways, protecting us from oxidative damage. An association between low levels of selenium and mood has also been found, potentially increasing symptoms of depression, anxiety and fatigue.

Where you’ll find it: Brazil nuts, meat and fish, nuts and seeds, wholegrains, legumes.


Omega-3 fatty acids are polyunsaturated fats that come in the forms EPA + DHA in marine oils, namely fish, and ALA found in plant oils. These types of fatty acids are used to make hormone-like substances, especially important as anti-inflammatories in our body. They are also important for hearth health, health of our nervous systems and brain and eye development and functioning.

The current idea is that these fatty acids are required for the synthesis of chemicals needed for the brain to function optimally. Regarding intake, higher levels of fish in one’s diet has been associated with a reduced risk of depression, while poor intake of fish has been associated with a higher risk of depression.

Where you’ll find it: oily fish such as sardines, mackerel and herring are good sources, though you can also source plant-based algal supplements for those who don’t consume fish. The ALA in plant foods is not as well converted to EPA + DHA, though they have plenty of health benefits either way, so good sources include chia seeds, flaxseeds, hemp seeds and tofu.


Tryptophan is an essential amino acid. This means we cannot make it ourselves; we must consume it in food. Tryptophan is involved in the synthesis of the ‘happy hormone’, serotonin, which is linked to feelings of happiness and well-being. It is also involved in the regulation of our sleep.

The evidence regarding tryptophan and it’s effects on mood aren’t solid, however the theory is that with the consumption of tryptophan-containing foods, and so, increase of tryptophan in our body, this may increase the amount of serotonin created in our brain. The consumption of carbohydrates may also increase levels of serotonin, by making tryptophan more available to us, and this is often associated with carbohydrate cravings as “comfort foods”.

Where you’ll find it: meat, eggs, tofu, cheese, nuts and seeds, and legumes.

The takeaway: There are many individual nutrients or components of food that have been found to play an important role in our mental health and functioning, these can be easily sourced through food and align with eating a varied, wholefood diet and not removing any foods groups if not necessary.


Carbohydrates, once digested, provide our body with glucose- our preferred source of energy. This energy is used for the functioning of all our organs, including the brain to keep up working our best each day.

When the glucose provided by a meal has been used up, our blood glucose levels drop. When this happens, our brain function and irritability worsen. So, the idea of being “hangry” isn’t so crazy after all- that isn’t to say there can’t be other factors in this situation.

However, providing our body with a steady, reliable source of energy has been associated with mood improvements, while lower glucose levels are associated with irritability, nervousness and anxiety.

The takeaway: The best way to consider this information for your daily habits is to opt for less refined carbohydrates, which are typically lower GI than their processed counterparts. So, choices like wholemeal/wholegrain bread, brown rice, barley, quinoa, whole fruits etc. Also, aiming to have balanced meals including protein, fibre and fats will aid in reducing the GI, providing the nutrients discussed above and, maybe help improve your mood!

Western Diet and inflammation

Okay, so the term inflammation is REALLY thrown around lately. It isn’t nearly as scary, clear cut or terrible as it sounds. However, it is a real response that occurs in our body. When our body feels we are at risk or injured, our immune cells and cytokine production increases in order to protect us.

Long-term, “chronic” inflammation can be harmful to our body and increase of risk of diseases such as diabetes, heart disease and arthritis, for example.

Far more research is still required, though a typical Western diet high in refined sugars, saturated fat and salt, but low in poly- and monounsaturated fats, antioxidants and fibre may increase our risk of this long-term inflammation in our body. Please consider, this is not the same as saying have one discretionary food will cause these immediate effects. This is not the case, it is the pattern and style of eating, long-term.

It is thought that when we have prolonged, higher levels of inflammation in our body, we may be more at risk of depression. One way this may occur is the changes to signalling with inflammation reducing chemicals like serotonin.

Another way inflammation may be linked to mental health that a typical Western diet, lacking foods like fruits and vegetables, then also potentially low in antioxidants, may cause an imbalance of free radicals in our body that then leads to inflammation. This is referred to as ‘oxidative stress’. Again, this isn’t always a bad thing- you’ll find oxidative stress when building muscle, for example. However, when this process is not balanced, our production of energy can be affected, impacting brain function and so, making us feel tired and irritable.

The takeaway: Just to be sure it’s heard, inflammation and oxidative stress are normal, healthy processes in our body. An imbalance is what can cause concern and a typical “Western diet” high in refined sugars, saturated fat and processed foods may increase long-term inflammation. Though, you don’t need to throw out everything in your pantry. Instead, including a varied, wholefood diet with lots of fruit and veg, whole grains and omega-3s is a good start.

Our Gut

While the term ‘gut health’ has many different uses, from a variety of health professionals and non-health professionals, we still have so much to learn about it. For example, we still don’t know what a “healthy gut” looks like. It likely varies individually. However, this space is rapidly growing on the quest to find out more.

Of particular importance to our mental health is the gut-brain axis. This refers to the communication between our brain and our gut…or more interestingly, our gut bacteria and our brain. I’m sure we are all familiar with feeling like we have “butterflies in our stomach”, or how feeling nervous might impact our gut function, though the interaction between the bacteria in our gut and our brain is something we are still learning about every day.

The collective term used to describe all the microorganisms in our gastrointestinal tract, is the microbiome. There are three mechanisms proposed to facilitate the communication between the microbiome and our brain. They are via the vagus nerve, which reaches all the way from the gut to the brain, through our microbiome triggering our immune system (of which >70% lives in our gastrointestinal tract), and by the chemicals produced by the microbiome that passes into our blood system and may cross the blood-brain barrier.

The last of this has been particularly popular in discussion of late, as different types of bacteria can produce different types of chemicals that are associated with mood including serotonin and dopamine. In fact, over 90% of our serotonin is produced in the gut. The imbalance of some of these chemicals are also associated with mental health conditions, though researchers are still trying to understand this process and whether these gut-produced chemicals can impact our brain. Similarly, stress, anxiety and trauma have been found the affect the diversity (variety of types) of our gut bacteria.

The takeaway: There’s still so much to learn about our microbiome and it’s influence on our health, as well as what a “healthy gut” looks like. Though, we do know that diversity is key in keep your gut in tip-top shape, whatever that may look like for you. The best way to encourage diversity is through eating a diet rich in plant foods, as they feed our gut bugs too, and the diversity of our food can change the presence of the bacteria surviving in our gut.

I’m nearly done!

Diet and mood have a really promising link, and I’m really excited for where this may go. Though, it is important to note that mental health conditions, and general low mood are multi-faceted. There are many things than contribute to our mental well-being and our ability to feel we can manage our own health and this is not looking to ignore that.

If this appeals to you, you are not alone but it can feel like a daunting task! Rather than feeling overwhelmed by trying to change every aspect of your diet, or not knowing where to start, I’d strongly advise working with a Dietitian as a complementary therapy to help you on your way and guide you to make changes that work for you, as an individual.

There’s even more you can read…


  • Francis, H., Stevenson, R., Chambers, J., Gupta, D., Newey, B., & Lim, C. (2019). A brief diet intervention can reduce symptoms of depression in young adults – A randomised controlled trial. PLOS ONE, 14(10), e0222768. doi: 10.1371/journal.pone.0222768

  • Jacka, F.N., O’Neil, A., Opie, R. et al. A randomised controlled trial of dietary improvement for adults with major depression (the ‘SMILES’ trial). BMC Med 15, 23 (2017).

  • Ljungberg, T., Bondza, E., & Lethin, C. (2020). Evidence of the Importance of Dietary Habits Regarding Depressive Symptoms and Depression. International journal of environmental research and public health, 17(5), 1616.

Specific nutrients

  • Alhassan, A., Young, J., Lean, M., & Lara, J. (2017). Consumption of fish and vascular risk factors: A systematic review and meta-analysis of intervention studies. Atherosclerosis, 266, 87-94. doi: 10.1016/j.atherosclerosis.2017.09.028

  • Appleton K, Rogers P, Ness A. Updated systematic review and meta-analysis of the effects of n-3 longchain polyunsaturated fatty acids on depressed mood. Am J Clin Nutr. 2010;91:757-770. 71.

  • Appleton KM, Sallis HM, Perry R, Ness AR, Churchill R. Omega-3 fatty acids for depression in adults. Cochrane Database Syst Rev. 2015;2015(11):CD004692. Published 2015 Nov 5. doi:10.1002/14651858.CD004692.pub4

  • Astorg P, Couthouis A, de Courcy G, et al. Association of folate intake with the occurrence of depressive episodes in middle-aged French men and women. Br J Nutr. 2008;100:183-187. 75.

  • Boyle, N. B., Lawton, C., & Dye, L. (2017). The Effects of Magnesium Supplementation on Subjective Anxiety and Stress-A Systematic Review. Nutrients, 9(5), 429.

  • Casper R. Diet and mental health: an up-to-date analysis. World Rev Nutr Diet. 2011;102:98-113. 72.

  • Dfarhud, D., Malmir, M., & Khanahmadi, M. (2014). Happiness & Health: The Biological Factors- Systematic Review Article. Iranian journal of public health, 43(11), 1468–1477.

  • Eby G, Eby K. Rapid recovery from major depression using magnesium treatment. Med Hypotheses. 2006;67.

  • Forsyth A, Williams P, Deane F. Nutrition status of primary care patients with depression and anxiety. Aust J Prim Health. 2012;18:172-176. 78.

  • Goren J, Tewksbury A. The use of omega-3 fatty acids in mental illness. J Pharm Prac. 2011;24:452- 471. 73. Lakhan S, Vieira K. Nutritional therapies for mental disorders. Nutr J. 2008;7:2 (doi:10.1186/1475- 2891-7-2).

  • Gosney MA, Hammond MF, Shenkin A, Allsup S. Effect of micronutrient supplementation on mood in nursing home residents. Gerontology. 2008;54(5):292-299. doi:10.1159/000131886

  • Hallahan B, Hibbeln JR, Davis JM, Garland MR. Omega-3 fatty acid supplementation in patients with recurrent self-harm. Single-centre double-blind randomised controlled trial. Br J Psychiatry. 2007 Feb;190:118-22. Abstract available from:


  • Kennedy D. O. (2016). B Vitamins and the Brain: Mechanisms, Dose and Efficacy--A Review. Nutrients, 8(2), 68.

  • Lakhan SE, Vieira KF. Nutritional therapies for mental disorders. Nutr J. 2008;7:2. Published 2008 Jan 21. doi:10.1186/1475-2891-7-2

  • Lakhan, S.E., Vieira, K.F. Nutritional therapies for mental disorders. Nutr J 7, 2 (2008).

  • Li F, Liu X, Zhang D. Fish consumption and risk of depression: a meta-analysis. J Epidemiol Community Health. 2016;70(3):299-304. doi:10.1136/jech-2015-206278

  • Liao, Y., Xie, B., Zhang, H. et al. Efficacy of omega-3 PUFAs in depression: A meta-analysis. Transl Psychiatry 9, 190 (2019).

  • McGarel, C., Pentieva, K., Strain, J., & McNulty, H. (2015). Emerging roles for folate and related B-vitamins in brain health across the lifecycle. Proceedings of the Nutrition Society, 74(1), 46-55. doi:10.1017/S0029665114001554

  • Nanri A, Mizoue T, Poudel-Tandukar K, Noda M, Kato M, Kurotani K, et al. Dietary patterns and suicide in Japanese adults: the Japan Public Health Center-based Prospective Study. Br J Psychiatry. 2013 Dec; 203(6):422-7. doi: 10.1192/bjp.bp.112.114793. Epub 2013 Oct 10. Abstract available from:

  • Okereke, O. I., Cook, N. R., Albert, C. M., Van Denburgh, M., Buring, J. E., & Manson, J. E. (2015). Effect of long-term supplementation with folic acid and B vitamins on risk of depression in older women. The British journal of psychiatry : the journal of mental science, 206(4), 324–331.

  • Okereke, O. I., Cook, N. R., Albert, C. M., Van Denburgh, M., Buring, J. E., & Manson, J. E. (2015). Effect of long-term supplementation with folic acid and B vitamins on risk of depression in older women. The British journal of psychiatry : the journal of mental science, 206(4), 324–331.

  • Petrilli, M. A., Kranz, T. M., Kleinhaus, K., Joe, P., Getz, M., Johnson, P., Chao, M. V., & Malaspina, D. (2017). The Emerging Role for Zinc in Depression and Psychosis. Frontiers in pharmacology, 8, 414.

  • Poudel-Tandukar K, Nanri A, Iwasaki M, Mizoue T, Matsushita Y, Takahashi Y, et al. Long chain n-3 fatty acids intake, fish consumption and suicide in a cohort of Japanese men and women--the Japan Public Health Center-based (JPHC) prospective study. J Affect Disord. 2011 Mar;129(1-3):282-8. doi: 10.1016/j.jad.2010.07.014. Epub 2010 Aug 9. Abstract available from:

  • Rao, T. S., Asha, M. R., Ramesh, B. N., & Rao, K. S. (2008). Understanding nutrition, depression and mental illnesses. Indian journal of psychiatry, 50(2), 77–82.

  • Richard J Wurtman, Judith J Wurtman, Meredith M Regan, Janine M McDermott, Rita H Tsay, Jeff J Breu, Effects of normal meals rich in carbohydrates or proteins on plasma tryptophan and tyrosine ratios, The American Journal of Clinical Nutrition, Volume 77, Issue 1, January 2003, Pages 128–132,

  • Sarris J, Mischoulon D, Schweitzer I. Adjunctive nutraceuticals with standard pharmacotherapies in bipolar disorder: a systematic review of clinical trials. Bipolar Disord. 2011;13(5-6):454-465. doi:10.1111/j.1399-5618.2011.00945.x

  • Sarris J, Mischoulon D, Schweitzer I. Omega-3 for bipolar disorder: meta-analyses of use in mania and bipolar depression. J Clin Psychiatry. 2012 Jan;73(1):81-6. Abstract available from:

  • Sarris J, Schoendorfer N, Kavanagh DJ. Major depressive disorder and nutritional medicine: a review of monotherapies and adjuvant treatments. Nutr Rev. 2009;67(3):125-131. doi:10.1111/j.1753-4887.2009.00180.x

  • Sullican LE, Fiellin DA, O’Connor PG. The prevalence and impact of alcohol problems in major depression: a systematic review. Am J Med. 2005 Apr 118(4):330-41. Abstract available from:

  • Szewczyk B, Kubera M, Nowak G. The role of zinc in neurodegenerative inflammatory pathways in depression. Prog Neuropsychopharmacol Biol Psychiatry. 2011;35(3):693-701. doi:10.1016/j.pnpbp.2010.02.010

  • Tamlin S Conner, Aimee C Richardson, Jody C Miller, Optimal Serum Selenium Concentrations Are Associated with Lower Depressive Symptoms and Negative Mood among Young Adults, The Journal of Nutrition, Volume 145, Issue 1, January 2015, Pages 59–65,

  • Taylor M, Carney S, Geddes G, et al. Folate for depressive disorders. Cochrane Database System Rev. 2003;2:CD003390. 76.

  • Taylor M, Carney S, Goodwin G, et al. Folate for depressive disorders: systematic review and meta-analysis of randomized controlled trials. J Psychopharmacol. 2004;18:251-256.

  • Tsai AC, Lucas M, Okereke OI, O'Reilly EJ, Mirzaei F, Kawachi I, et al. Suicide mortality in relation to dietary intake of n-3 and n-6 polyunsaturated fatty acids and fish: equivocal findings from 3 large US cohort studies. Am J Epidemiol. 2014 Jun 15;179(12):1458-66. Available from:

  • Wu S, Ding Y, Wu F, Xie G, Hou J, Mao P. Serum lipid levels and suicidality: a meta-analysis of 65 epidemiological studies. J Psychiatry Neurosci. 2016 Jan 14(1):56-69. Abstract available from: https://

  • Young SN. Folate and depression--a neglected problem. J Psychiatry Neurosci. 2007;32(2):80-82.


  • Benton, D. (2002). Carbohydrate ingestion, blood glucose and mood. Neuroscience & Biobehavioral Reviews, 26(3), 293-308. doi: 10.1016/s0149-7634(02)00004-0

  • Gangwisch, J. E., Hale, L., Garcia, L., Malaspina, D., Opler, M. G., Payne, M. E., Rossom, R. C., & Lane, D. (2015). High glycemic index diet as a risk factor for depression: analyses from the Women's Health Initiative. The American journal of clinical nutrition, 102(2), 454–463.

  • Rausch, Joseph. (2010). Measures of Glycemic Variability and Links with Psychological Functioning. Current diabetes reports. 10. 415-21. 10.1007/s11892-010-0152-0.

  • Salari-Moghaddam A, Saneei P, Larijani B, Esmaillzadeh A. Glycemic index, glycemic load, and depression: a systematic review and meta-analysis. Eur J Clin Nutr. 2019;73(3):356-365. doi:10.1038/s41430-018-0258-z

  • Sünram-Lea SI, Foster JK, Durlach P, Perez C. Glucose facilitation of cognitive performance in healthy young adults: examination of the influence of fast-duration, time of day and pre-consumption plasma glucose levels. Psychopharmacology (Berl). 2001;157(1):46-54. doi:10.1007/s002130100771


  • 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.

  • Sarandol A, Sarandol E, Eker SS, Erdinc S, Vatansever E, Kirli S. Major depressive disorder is accompanied with oxidative stress: short-term antidepressant treatment does not alter oxidative-antioxidative systems. Hum Psychopharmacol. 2007;22(2):67-73. doi:10.1002/hup.829

  • Gut health

  • Carabotti, M., Scirocco, A., Maselli, M. A., & Severi, C. (2015). The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems. Annals of gastroenterology, 28(2), 203–209.

  • Christ, A., Lauterbach, M., & Latz, E. (2019). Western Diet and the Immune System: An Inflammatory Connection. Immunity, 51(5), 794-811. doi: 10.1016/j.immuni.2019.09.020

  • Estruch R. Anti-inflammatory effects of the Mediterranean diet: the experience of the PREDIMED study. Proc Nutr Soc. 2010;69(3):333-340. doi:10.1017/S0029665110001539

  • Estruch, R. (2010). Anti-inflammatory effects of the Mediterranean diet: The experience of the PREDIMED study. Proceedings of the Nutrition Society, 69(3), 333-340. doi:10.1017/S0029665110001539

  • Le Port A, Gueguen A, Kesse-Guyot E, et al. Association between dietary patterns and depressive symptoms over time: a 10-year follow-up study of the GAZEL cohort. PLoS One. 2012;7(12):e51593. doi:10.1371/journal.pone.0051593

  • O'Neil, A., Quirk, S. E., Housden, S., Brennan, S. L., Williams, L. J., Pasco, J. A., Berk, M., & Jacka, F. N. (2014). Relationship between diet and mental health in children and adolescents: a systematic review. American journal of public health, 104(10), e31–e42.

  • Osadchiy V, Martin CR, Mayer EA. Gut Microbiome and Modulation of CNS Function. Compr Physiol. 2019;10(1):57-72. Published 2019 Dec 18. doi:10.1002/cphy.c180031

  • Pellissier S, Dantzer C, Mondillon L, et al. Relationship between vagal tone, cortisol, TNF-alpha, epinephrine and negative affects in Crohn's disease and irritable bowel syndrome. PLoS One. 2014;9(9):e105328. Published 2014 Sep 10. doi:10.1371/journal.pone.0105328

  • Tolkien K, Bradburn S, Murgatroyd C. An anti-inflammatory diet as a potential intervention for depressive disorders: A systematic review and meta-analysis. Clin Nutr. 2019;38(5):2045-2052. doi:10.1016/j.clnu.2018.11.007

  • I really enjoyed this podcast:

94 views0 comments

Recent Posts

See All


bottom of page