Does Diet Affect Our Mood?

The expansion of mental health awareness has been more prevalent in recent years. It is talked about on the news, social media, and we have an entire month dedicated to it every year. All of this is with good reason too. Depression is the leader of disability worldwide, with an estimated 264 million people affected by depression (1). Strategies to help prevent and treat depression and other mental health disorders are varied, as they are driven by social, economic, and environmental factors. But what about our food? Does what we put into our bodies every day influence our mood and the risk for developing depression? Well, research has shown that this may be the case and that nutrition can play a role in our moods. Outlined below are a few areas of research that look to be promising in dietetics:

Key Nutrients

Regarding nutrients in the food we eat, most of the deficiencies seen in those with mental health disorders include omega-fatty acids, B vitamins, minerals, and amino acids (2). A recent meta-analysis on dietary patterns and depression risk states that a high intake of antioxidant-rich food (as found in fruits and vegetables) may have beneficial protective effects against depression (3). This means that dietary patterns rich with foods that offer these benefits can possibly prevent or offset symptoms of depression. This falls in line with this study’s findings that higher intake of fruit, vegetables, whole grains, fish, olive oil, and low-fat dairy products lowers the probability or risk for depression (3). On the flip side, a higher consumption of red and/or processed meat, refined grains, sweets, and high-fat dairy products increase this risk.  

Pathways to a better mood

There are several biological mechanisms of action that modulate our mood. The effects that nutrition has on these pathways may be the reason that food plays an important role. 

Inflammation: Mental health disorders are associated with heightened inflammation. This is marked by an increase in pro-inflammatory markers, such as IL-1 and IL-6 (4). Dietary patterns rich in polyphenols, antioxidants, and polyunsaturated fatty acids, such as found in the Mediterranean diet, are associated with lower levels of inflammatory markers (5). 

Oxidative stress: An increase in reactive nitrogen and oxygen species is also associated with depression, affecting antioxidant defense and other important cellular processes (6). These processes are influenced by our diet by strengthening our antioxidant capacity and protecting against cell damage. Dietary sources of vitamins A, C, and E can protect against the effects of oxidative stress. Additionally, minerals such as selenium, copper, and zinc play important roles as cofactors in oxidative pathways (7). This confirms that a diet offering a diverse array of nutrients can be nourishing for both our bodies and minds. 

Neurotransmitter pathways: Neurotransmitters are important for brain health because they act as chemical messengers for our brain’s activity (8). Disturbances in this activity are seen in many mood disorders. Specific amino acids are precursors that play a role in the synthesis of neurotransmitters (7). Together with other nutrients, such as vitamin B6, amino acid metabolism forms epinephrine, norepinephrine, serotonin, and γ-amino butyric acid (7). Neuron development also relies heavily on EPA and DHA, derived from omega-3-fatty acid, an essential fatty acid (7). This means that there may be a role in our brain function from foods like fish, legumes, nuts, seeds, cereals, and fresh fruit and vegetables. 

Dietary Patterns or Nutraceuticals?

With all this being said, is it better to focus on our overall dietary pattern, or would the general population benefit from taking supplements of the specific nutrients (like an omega-3 supplement) missing from their diet? Nutraceuticals, which is an expansive area of nutrition research, may be effective in targeting specific pathways in mental illness. However, the research is largely mixed and not consistent enough to prescribe to those with specific mental illnesses. In addition, not enough clinical trials have been done for those with diagnosed mental illness (9). Dietary interventions have provided a lot of consistent evidence that there are associations between dietary patterns and mental illness (9). So, our focus may be more beneficial on eating a colorful plate filled with fruits, vegetables, protein, whole grains, and healthy fats, to cover all our bases. It’s important to note that many studies on dietary patterns are observational, so we also need more clinical trials to confirm these findings. As previously mentioned, several factors play a role in the development of mental disorders. Diet alone can be a source of stress for some that may be dealing with food insecurity, economic distress, and social factors that can affect our mental well-being. There is still a lot to learn, but we are moving in the right direction in terms of the positive effect that nutrition can have on our mood. 

Edited by PreRD intern, Lauren Gatto

Written by Vanessa Chiriboga: Hi, my name is Vanessa. I received my Master of Science in Nutrition degree from Hunter College in May 2021. I am currently taking the year off before completing my dietetic internship in the 2022-2023 school year. I am so excited for my future in the dietetics field and the impact I can have on others to prevent and treat chronic diseases. I’m also interested in sports nutrition and would love to work with dancers on the importance of fueling properly and finding balance with their busy schedules. I love to cook, write, and do lots of yoga!

References 

1. Mental disorders. Accessed October 18, 2021. https://www.who.int/news-room/fact-sheets/detail/mental-disorders

2. Rao TSS, Asha MR, Ramesh BN, Rao KSJ. Understanding nutrition, depression and mental illnesses. Indian J Psychiatry. 2008;50(2):77-82. doi:10.4103/0019-5545.42391

3. Li Y, Lv M-R, Wei Y-J, et al. Dietary patterns and depression risk: A meta-analysis. Psychiatry Research. 2017;253:373-382. doi:10.1016/j.psychres.2017.04.020

4. Berk M, Williams LJ, Jacka FN, et al. So depression is an inflammatory disease, but where does the inflammation come from? BMC Medicine. 2013;11(1):200. doi:10.1186/1741-7015-11-200

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

6. Moylan S, Berk M, Dean OM, et al. Oxidative & nitrosative stress in depression: Why so much stress? Neuroscience & Biobehavioral Reviews. 2014;45:46-62. doi:10.1016/j.neubiorev.2014.05.007 

7. Parletta N, Milte CM, Meyer BJ. Nutritional modulation of cognitive function and mental health. The Journal of Nutritional Biochemistry. 2013;24(5):725-743. doi:10.1016/j.jnutbio.2013.01.002 

8. Sheffler ZM, Reddy V, Pillarisetty LS. Physiology, Neurotransmitters. In: StatPearls. StatPearls Publishing; 2021. Accessed October 21, 2021. http://www.ncbi.nlm.nih.gov/books/NBK539894/

9. Marx W, Moseley G, Berk M, Jacka F. Nutritional psychiatry: the present state of the evidence. Proceedings of the Nutrition Society. 2017;76(4):427-436. doi:10.1017/S0029665117002026