Depression is becoming one of the leading causes of morbidity and mortality. According to the World Health Organization, depression is the second leading cause of disease and injury after ischemic heart disease (1).
Food is vital for mental health. Certain foods can improve brain function by promoting elements like BDNF crucial for brain plasticity.
Food can also influence the inflammatory status in the body that affects brain functioning. Finally, food greatly influences the microbes in our bodies that are important for brain health (2).
A drastic change in the western diet from whole foods(traditional foods) to fast food is correlated with an increase in the incidence of reported depression cases.
Research shows that traditional foods that include vegetables, fruits, fish meat, and grains reduce the risk of major depression compared to a western diet that has processed, refined grains, and surgery products (3).
It is also true that highly processed food that lacks vital micronutrients is also the cause of many health problems. These micronutrients are present in copious amounts in whole foods.
Specific micronutrients have been shown to improve symptoms of depression and anxiety in population or controlled clinical studies. Their deficiency has been linked to depression and anxiety.
These include
- Omega-3
- Vitamin D
- Magnesium
- Zinc
- Vitamin B
- Selenium
1) Omega-3
The omega-3 polyunsaturated fatty acid (PUFA) are essential building blocks of our brains. DHA, omega-3 type makes up 10-15% of the total fatty acids.
The change in food in the western world from unsaturated to saturated fatty acids has reduced the total intake of PUFAs.
EPA has shown to be more potent in reducing the symptoms of depression compared to DHA in patients with major depression and unipolar depression (4,5).
People with anxiety and depression have low levels of omega-3’s in their blood and supplementation improves psychiatric symptoms (6).
It is worth mentioning that some studies have found no significant effect of omega-3 supplementation in the treatment of depressive disorders. These differences are due to study design and parameters differences (7, 8).
Omega-3 may provide benefits in lessening the symptoms of depression.
Fatty fish is rich in omega-3
Fatty fish such as Salmon, Anchovy, mackerel, tuna, herring, and sardines are great sources of omega-3.
One serving of these fatty fish provides between 1.5 to 3.5g of omega-3 fatty acids (9).
Other sources of omega-3: Chia seeds, flaxseeds, tofu, eggs, and soybeans are sources of omega-3 and are also vegetarian friendly. American Heart Association recommends 2 servings of fatty fish to account for 250 to 500 mg of omega-3 per day (10).
More information on omega-3 can be obtained here.
2) Vitamin D
The role of vitamin D is implicated in depression and anxiety. The active form of vitamin D,(1,25-dihydroxyvitamin D3), or simply vitamin D3 has an immunomodulatory and anti-inflammatory function which is considered one of the ways vitamin D can impact depression and anxiety (11).
Increased inflammation level is associated with depression (12).
Vitamin D also has a neuroprotective function because of its strong antioxidant property (13).
Moreover, vitamin D receptors are present in brain cells that can alter mood (14).
How vitamin D affects depression and anxiety is still unknown.
Several studies have found that people suffering from depression have low levels of vitamin D mostly in older individuals. And lower vitamin D levels are associated with a higher risk of depression (15,16,17).
Randomized control studies have shown that vitamin D supplementation is beneficial in mild to moderate clinical depression (18,19,20).
Other research has shown the benefits of vitamin D supplementation in anxiety but not in depression (21).
Vitamin D is strongly associated with depression and anxiety due to its immunomodulation, antioxidant and anti-inflammatory role.
Organ meat (offal) are high in Vitamin D3
Sunlight is one of the natural ways to obtain vitamin D. Vitamin D3 can also be obtained from food sources. Most of the vitamin D3 food sources are animal-based.
Animal meat and especially, organ meat such as liver is high in vitamin D3. Cow kidneys are high in vitamin D3 as well (22,23)
Some farmers use fortified animal feed which provides a high concentration of vitamin D3 in meat and organs.
Other sources of vitamin D: Other sources of vitamin D include fish such as Salmon, Herring, and Tuna. Eel has a high content of vitamin D. Vegetarian sources of vitamin D are eggs, mushrooms, and dairy products.
As per NIH, the Dietary Allowance of vitamin D in an average adult is 15 micrograms and for individuals over 70 is 20 micrograms (24).
3) Magnesium
Magnesium deficiency is linked to depression. The idea to use magnesium for depression has been around for more than a century.
Research shows that people suffering from depression have low magnesium levels. And high levels of magnesium are associated with low depression risk (25).
Magnesium supplementation use can reduce the symptoms of mild to moderate depression and anxiety. Magnesium supplementation is safe and well-tolerated among people treated (26).
Magnesium also helps lessen the symptoms of major depression (27).
One study focused on Gitelman’s syndrome in a patient. The magnesium treatment drastically benefited the patient’s depression and anxiety. This further indicates that magnesium is a vital mineral for mood and the brain (28).
In summary, magnesium has been used to treat depression and anxiety for a long time. The inclusion of magnesium in our diets can decrease the risk of depression and anxiety.
Pumpkin seeds are high in magnesium
The major sources of magnesium are non-animal products. Nuts and seeds are a great source of magnesium. Pumpkin seeds in particular are high in magnesium.
According to the NIH, one serving of pumpkin seeds (1 oz.) provides 156 mg of magnesium.
Green vegetables, for example, Spinach provide 76 mg magnesium per ½ cup.
Other sources of magnesium: Chia seeds, almonds, cashews, are also high in magnesium. Cereals have high quantities of magnesium as well. All of these options are vegetarian-friendly.
NIH recommended dietary allowance of an average adult is between 320 to 420 mg (29).
4) Zinc
Zinc is required for brain function. Research shows that zinc is important for both neurological and psychiatric diseases.
Zinc imbalance is noted in neurological diseases such as Alzheimer’s disease and Parkinson’s disease as well as psychiatric diseases that include schizophrenia, attention deficit and hyperactivity disorder (ADHD), and depression (30).
Individuals suffering from depression have lower Zinc blood levels compared the people without depression (31).
Clinical studies have shown a positive effect in individuals with a depressive state after using zinc as adjunctive therapy (32,33).
One of the ways zinc benefits depressive state is by increasing the BDNF levels in the brain (34).
Zinc deficiency is observed in patients suffering from depression. Zinc supplementation benefits these individuals. Therefore, including diets with adequate amounts of zinc can be helpful.
Oysters are a great source of zinc
Zinc is mostly obtained from animal products. Oysters are high in zinc. As per NIH, 3 oz. will give approximately 74 mg of Zinc.
Other sources of zinc: Beef has a high zinc content. The beef chuck gives 7 mg of zinc per serving. Alaskan king crab and lobsters are also high in zinc.
Vegetarian sources of zinc are baked beans, breakfast cereals, pumpkin seeds, and yogurt.
NIH recommended dietary allowance is of an average adult is 8-11mg (35).
5) Vitamin B
Vitamin B12(cobalamin) is an important player in DNA synthesis and neurological function.
Vitamin B12 deficiency is associated with depression and dementia.
Oral supplementation is effective in reversing the vitamin B12 deficiency (36).
And good treatment response in major depressive disorder is observed in people with high B12 levels (37).
Low folate (B9) levels are observed in patients with depression (38). Similar to B12, low folate levels are associated with poor response to treatment for depression. Low folate levels can also lead to relapse or delayed treatment response (39,40).
Low levels of vitamin B12 and folate are associated with depression. Regular intake of Vitamin B12 and Folate can minimize the risk of depression.
Folate is present in Leafy greens vegetables
Major sources of Folate are leafy greens, fruits, legumes, pulses, and liver (41). As per the National Institute of Health, ½ cup of Spinach provides 131 micrograms of folate. The dietary allowance of folate for an average adult is 400 micrograms (42).
Beef liver is high in B12. According to the NIH, a single 3 oz. serving gives 70.7 micrograms of B12. Clams and Tuna are other sources of VitmainB12.
Yogurt and milk are vegetarian sources of B12.
The dietary allowance of B12 for an average adult is 2.4 micrograms (43).
6) Selenium
Selenium becomes part of selenoproteins that are an important group of proteins. Selenoproteins are involved in many functions including hormone metabolism and reducing oxidative stress by anti-oxidant function (44). Selenium deficiency can cause reduced BDNF expression (45).
Early research has shown a correlation between selenium and depression. Especially, good evidence is available for postpartum depression (46).
Other studies have shown the insignificant effect of selenium on depression (47).
Recent observational research shows the high intake of selenium is associated with a lower prevalence of depression after adjusting variables (48,49).
Although, selenium plays a crucial role in brain function and recent observational studies show that selenium is important for depression more studies are needed for absolute clarity
Brazil nuts are high in selenium
Brazil nuts have the highest amount of selenium per serving. As per NIH, 1 ounce (6-8 nuts) of brazil nuts provide 544 micrograms.
Other sources of selenium: Other sources include Yellowfin Tuna, Halibut, Ham, shrimps, and beef liver.
Vegetarian sources of selenium are cottage cheese, eggs, baked beans, and oatmeal.
the dietary allowance of Selenium for an average adult is 55 micrograms(50).
The Gist
Multiple studies have shown that deficiency of certain micronutrients plays an important role in the development of depression and anxiety. For example, studies on individual elements like magnesium, Vitamin B, zinc, and omega-3 show that supplementation is beneficial for depression and anxiety patients.
Seafood and fish, organ meat, leafy green vegetables, fruits, beans, cheese, and milk will provide all the above elements important to reduce the risk of depression.
