Defeating Depression Through Diet

Lather, rinse, repeat. Sometimes poor eating habits become a vicious cycle. We’re disappointed or sad about something, so we “treat ourselves” to a bag of chips or a big candy bar. We’re not really hungry; we’re just feeding an emotion. But that habit of grabbing processed food when we’re feeling blue may exacerbate those negative feelings, especially depression.

Ultra-Processed Defined

What is processed food? In theory, any food that ends up in the grocery store goes through some processing. According to the Department of Agriculture, processed foods are any foods that are changed from their natural state. This can include cut, washed, heated, pasteurized, canned, cooked, frozen, dried, dehydrated, mixed, or packaged food. It can also include food with added preservatives, nutrients, flavors, salts, sugars, or fats. 1

Ultra-processed food includes foods that are typically the result of intensive manufacturing processes. They’re made from foods plus additives and may not contain much of the original whole food.

These foods usually contain more sugars, oils, fats, and salt. They may also have ingredients extracted from other foods, like casein, lactose, gluten, whey, hydrogenated oils, protein isolate, maltodextrin, invert sugar, and high-fructose corn syrup. They could even have nutritious ingredients added, such as fiber, vitamins, or minerals.1

Processed Food, Disease, and Depression

Too much ultra-processed food has been found to raise the risk of heart disease, obesity, and certain cancers. There are plenty of studies that show this connection.1 A systematic review of the intake of processed food finds an increase in waist circumference, low HDL levels, and increased risk for metabolic syndrome. 3 Most ultra-processed foods are high in saturated fat, sugar, and sodium- the very nutrients the US Dietary Guidelines advise us to limit. 4

More research suggests that the risk for anxiety and depression is linked to poor dietary habits and a Western Diet. This could be related to the gut-brain axis and disruption in gut microbiota or the impact that highly processed foods have on inflammation and blood sugar. 5

A recent Italian study found a relationship between the consumption of ultra-processed foods and symptoms of depression in young adults. The study used food frequency questionnaires in nearly 600 adults aged 18 to 35 years of age and discovered a positive link between intake of ultra-processed food and symptoms of depression. Results were adjusted for adherence to a Mediterranean diet, which has been found to be protective. 6

A meta-analysis of observational studies also supports the association between ultra-processed foods and worse mental health. Higher intake of ultra-processed foods was linked with increased odds of depression and anxiety in 17 observational studies. These associations were seen both together (anxiety and depression) and separately (anxiety or depression) with ultra-processed food intake. 7

Mediterranean Diet and Depression

As mentioned above, a Mediterranean-style diet may put you in a better state of mind. One study in over 150 adults with depression found that individuals attending a 3-month Med-diet cooking class along with the use of fish oil supplements had better fruit, vegetable, legume, nuts, and whole grain intake and reduced intake of red meat and unhealthy snacks. Depressive symptoms were kept at bay for 6 months after the intervention. 8

In addition, a randomized control trial in young men with depression (aged 18 to 25 years) also indicates that a Mediterranean-style diet may alleviate depressive symptoms. A 12-week intervention of a Mediterranean diet or “befriending” (control group), found better adherence to a Mediterranean diet and more change in the Beck Depression Inventory Scale. Quality of life scores was also higher in the Mediterranean group. 9

While vegetables, legumes, and whole grains are a big part of the Mediterranean diet, a vegetarian diet was not correlated with a reduced risk of depression, anxiety, or stress. A recent systematic review and meta-analysis of observational studies found no link between a vegetarian diet and depression or anxiety. Further research is needed in this area. 10

Top 8 Foods to Eat to Improve Mental Health

There are lots of great foods to consume to reduce the risk of depression. Here are my top 10:

1. Whole grains like rolled oats provide complex carbohydrates as well as tryptophan, a neurotransmitter associated with good mood.

2. Fruits and vegetables. Higher intakes of fruits and vegetables have been found to be beneficial in reducing the incidence of depression in middle-aged and older adults in a recent systematic review and meta-analysis. 11

3. Beans and other legumes. Beans contain plenty of dietary fiber, which has been found to reduce the risk of depression. 12

4. Fish- especially fatty fish. Salmon, tuna, and mackerel are sources of omega-3 fatty acids, a healthy fat linked with a reduction in inflammation. A meta-analysis of studies indicates that fish higher fish intake is linked with reduced rates of depression. 13

5. Green leafy vegetables. Leafy greens are a source of folate. One study found that subjects with normal levels of folate and B12 (versus low levels) had lower rates of depression. 14

6. Nuts and seeds, especially walnuts. Walnuts are a plant source of omega-3 fatty acids. A recent study found that nut eaters had lower depression scores than non-nut eaters. The impact was strongest in women. 15

7. Yogurt and other fermented dairy foods. A recent meta-analysis of cohort studies indicated that fermented dairy intake was associated with lower rates of depression. The authors believe this is related to the gut-brain axis. 16

8. Extra virgin olive oil. It’s not just good for your heart. The use of EVOO was found to reduce symptoms of depression in those dealing with severe depression but not mild to moderate depression. It certainly can’t hurt to use it in place of other oils. 17

References:

1.    USDA

2.    Suksatan W, Moradi S, Naeini F, Bagheri R, Mohammadi H, Talebi S, Mehrabani S, Hojjati Kermani MA, Suzuki K. Ultra-Processed Food Consumption and Adult Mortality Risk: A Systematic Review and Dose-Response Meta-Analysis of 207,291 Participants. Nutrients. 2021 Dec 30;14(1):174. doi: 10.3390/nu14010174. PMID: 35011048; PMCID: PMC8747520.

3.    Pagliai G, Dinu M, Madarena MP, Bonaccio M, Iacoviello L, Sofi F. Consumption of ultra-processed foods and health status: a systematic review and meta-analysis. Br J Nutr. 2021 Feb 14;125(3):308-318. doi: 10.1017/S0007114520002688. Epub 2020 Aug 14. PMID: 32792031; PMCID: PMC7844609.

4.    Home | Dietary Guidelines for Americans

5.    Bear TLK, Dalziel JE, Coad J, Roy NC, Butts CA, Gopal PK. The Role of the Gut Microbiota in Dietary Interventions for Depression and Anxiety. Adv Nutr. 2020 Jul 1;11(4):890-907. doi: 10.1093/advances/nmaa016. PMID: 32149335; PMCID: PMC7360462.

6.    Godos J, Bonaccio M, Al-Qahtani WH, Marx W, Lane MM, Leggio GM, Grosso G. Ultra-Processed Food Consumption and Depressive Symptoms in a Mediterranean Cohort. Nutrients. 2023 Jan 18;15(3):504. doi: 10.3390/nu15030504. PMID: 36771211; PMCID: PMC9919031.

7.    Lane MM, Gamage E, Travica N, Dissanayaka T, Ashtree DN, Gauci S, Lotfaliany M, O'Neil A, Jacka FN, Marx W. Ultra-Processed Food Consumption and Mental Health: A Systematic Review and Meta-Analysis of Observational Studies. Nutrients. 2022 Jun 21;14(13):2568. doi: 10.3390/nu14132568. PMID: 35807749; PMCID: PMC9268228.

8.    Parletta N, Zarnowiecki D, Cho J, Wilson A, Bogomolova S, Villani A, Itsiopoulos C, Niyonsenga T, Blunden S, Meyer B, Segal L, Baune BT, O'Dea K. A Mediterranean-style dietary intervention supplemented with fish oil improves diet quality and mental health in people with depression: A randomized controlled trial (HELFIMED). Nutr Neurosci. 2019 Jul;22(7):474-487. doi: 10.1080/1028415X.2017.1411320. Epub 2017 Dec 7. PMID: 29215971.

9.    Bayes J, Schloss J, Sibbritt D. The effect of a Mediterranean diet on the symptoms of depression in young males (the "AMMEND: A Mediterranean Diet in MEN with Depression" study): a randomized controlled trial. Am J Clin Nutr. 2022 Aug 4;116(2):572-580. doi: 10.1093/ajcn/nqac106. PMID: 35441666.

10. Askari M, Daneshzad E, Darooghegi Mofrad M, Bellissimo N, Suitor K, Azadbakht L. Vegetarian diet and the risk of depression, anxiety, and stress symptoms: a systematic review and meta-analysis of observational studies. Crit Rev Food Sci Nutr. 2022;62(1):261-271. doi: 10.1080/10408398.2020.1814991. Epub 2020 Sep 4. PMID: 32885996.

11. Matison AP, Mather KA, Flood VM, Reppermund S. Associations between nutrition and the incidence of depression in middle-aged and older adults: A systematic review and meta-analysis of prospective observational population-based studies. Ageing Res Rev. 2021 Sep;70:101403. doi: 10.1016/j.arr.2021.101403. Epub 2021 Jul 8. PMID: 34246793.

12. Somaye Fatahi, Shakiba Shoaee Matin, Mohammad Hassan Sohouli, Mihnea-Alexandru Găman, Pourya Raee, Beheshteh Olang, Vaani Kathirgamathamby, Heitor O. Santos, Nathalia Sernizon Guimarães, Farzad Shidfar, Association of dietary fiber and depression symptom: A systematic review and meta-analysis of observational studies, Complementary Therapies in Medicine, Volume 56, 2021, 102621

13. Li F, Liu X, Zhang D Fish consumption and risk of depression: a meta-analysis J Epidemiol Community Health 2016;70:299-304

14. Khosravi, M., Sotoudeh, G., Amini, M. et al. The relationship between dietary patterns and depression mediated by serum levels of Folate and vitamin B12. BMC Psychiatry 20, 63 (2020). https://doi.org/10.1186/s12888-020-2455-2

15. Arab L, Guo R, Elashoff D. Lower Depression Scores among Walnut Consumers in NHANES. Nutrients. 2019 Jan 26;11(2):275. doi: 10.3390/nu11020275. PMID: 30691167; PMCID: PMC6413101.

16. Luo Y, Li Z, Gu L, Zhang K. Fermented dairy foods consumption and depressive symptoms: A meta-analysis of cohort studies. PLoS One. 2023 Feb 6;18(2):e0281346. doi: 10.1371/journal.pone.0281346. PMID: 36745637; PMCID: PMC9901789.

17. Foshati S, Ghanizadeh A, Akhlaghi M. Extra-Virgin Olive Oil Improves Depression Symptoms Without Affecting Salivary Cortisol and Brain-Derived Neurotrophic Factor in Patients With Major Depression: A Double-Blind Randomized Controlled Trial. J Acad Nutr Diet. 2022 Feb;122(2):284-297.e1. doi: 10.1016/j.jand.2021.07.016. Epub 2021 Aug 3. PMID: 34358723.