Depression is a sad reality that affects many people in the modern world.
This article will examine the links between depression and nutrition, and nutritional strategies that may help fight it.
What is Crippling Depression?
Unfortunately, some people experience “crippling depression,” which refers to a severe depression that controls someone’s entire life.
Sadly, this condition causes people to lose interest in work, study, family, and even makes sleep and basic tasks difficult.
According to the Anxiety and Depression Association of America, the lifetime risk for this major depression is 17% (3).
Suffering from frequent and severe bouts of depression is extremely serious and can even be fatal.
For example, recent high-profile suicide cases such as Robin Williams and Chester Bennington both suffered from long-term depression.
Signs and Symptoms
Depression can manifest itself in many ways, and the signs and symptoms can differ from person to person.
However, some common signs and symptoms of depression include (4);
- Changes in appetite
- Feelings of guilt
- Insomnia and other sleep disturbances
- Lack of focus
- Loss of interest in hobbies
- Persistent sadness
- Poor concentration
- Weight loss
Anyone who suspects they may be suffering from depression should make an appointment with their doctor.
“What causes depression?” is a question with no singular answer.
In brief, depression is likely multifactorial in causation.
There has been a lot of research looking into how depression starts, but as yet there doesn’t appear to be any single proven factor.
Interestingly, emerging science suggests that our diet and overall lifestyle play a significant role in depression too.
Also, there are the things which we don’t do.
Links Between Crippling Depression and Nutrition
Before we take a look at the links between severe depression and nutrition, it’s worth noting that physicians often don’t consider nutritional factors.
In the mainstream view, depression is very much considered to have biochemical and emotional roots.
While these are both common causes, there is far too much evidence to ignore the role our diet plays.
The problem here is that, following a diagnosis of depression, antidepressant drugs may be given without the patient even realizing their diet may be playing a role in the condition.
By no means does this suggest that antidepressant drugs and conventional treatment don’t help people; they clearly do.
However, beating crippling depression is difficult enough already, particularly so if we ignore a potential root cause.
It’s therefore worth understanding the nutritional component of the condition and discussing any concerns with your doctor.
Evidence Linking Our Diet to Depression
The highest level of scientific evidence—randomized controlled trials and systematic reviews—supports the link between diet and depression.
There are dozens of studies and far too many to list, but here is just a small selection of them;
Randomized Controlled Trials
- A 12-week study compared dietary intervention against a social support control group. The dietary intervention group showed significantly greater improvements as measured by the Montgomery-Asberg Depression Rating Scale. Additionally, they showed greater improvements in mood and anxiety (13).
- Randomized, placebo-controlled trials show that dietary intervention with omega-3 fatty acids and probiotics help improve the level of depression (14, 15).
- A systematic review investigating the association between mental health and diet quality analyzed studies between 2005 and 2013. The study found that healthy diets are inversely associated with depression. In contrast, poor quality diets displayed a positive association with depression and stress (16).
- Dietary intervention was found to have a significant effect on depression in half of the studies published between 1971 and 2014. This systematic review found that the effective dietary interventions were “less likely to recommend reducing red meat intake, selecting leaner meat products or following a low-cholesterol diet” (17).
10 Common Nutrient Deficiencies That Can Cause Depression
Before writing this article, I discussed the issue of diet and depression with a psychiatrist I know.
Notably, she told me that the first thing she does is test her patients for potential nutrient deficiencies.
Given that several nutrient deficiencies are linked with the development of extreme depression, this makes a lot of sense.
However, it is far from the norm and—from what I understand—many psychiatrists fail to test for any nutritional deficiency at all.
The following ten nutrient deficiencies may all play a role in the development of depression.
1. Omega-3 Fatty Acids
This nutrient is the big one, and a large body of research shows the importance of omega-3 for mental health.
The omega-3 fatty acids eicosapentaenoic acid (EPA) and especially docosahexaenoic acid (DHA) are essential for the health and development of our brain at all ages (18).
Unfortunately, a deficiency in these fatty acids is commonplace.
There are two reasons for this, the first of which is that people are not consuming enough oily fish such as mackerel, salmon, and sardines.
Secondly, the consumption of omega-6 fatty acids from vegetable oil is much higher than at any point in history. The problem here is that omega-6 fats compete for uptake with omega-3.
The best way to solve any potential omega-3 deficiency is to remove omega-6 vegetable oils from the diet.
Next, eating a few portions of oily fish each week will substantially improve omega-3 levels.
A second major deficiency to be aware of is protein.
Alongside the B vitamin group and omega-3 fatty acids, amino acids are one of the most common deficiencies seen in individuals with mental health conditions (21)
We can improve our amino acid status by consuming adequate meat, eggs, fish and other foods rich in dietary protein.
Iron is the biggest mineral deficiency in the world.
Randomized controlled trials also show that iron supplementation significantly improves postpartum depression (PPD) in new mothers (26).
Additionally, the higher the iron deficiency, the longer the mothers suffered from depression.
The single best way to improve iron stores is by eating red meat such as beef and lamb.
Magnesium is one of the most important minerals for our overall health.
Luckily, there are many healthy (and delicious) dietary sources of magnesium.
Estimates place up to 1 billion people globally as having an insufficient intake of selenium (31).
Selenium deficiency has wide-ranging effects on our body, and it’s particularly damaging for the immune system (32)
A randomized trial shows that selenium positively impacts postpartum depression (33).
The best dietary sources of selenium include brazil nuts, fish, and meat.
Iodine is an important mineral which we can mostly find in sea vegetables, vegetables that grow in iodine-rich soil, and drinking water (36).
For a sufficient intake, it’s beneficial to include iodized salt and sea vegetables such as seaweed in the diet.
7. Vitamin D
Getting enough vitamin D has an impressive list of benefits, ranging from a reduction in cancer risk to better immunity and lower inflammation (41).
Ensuring sufficient vitamin D also appears to lower the risk of suffering from crippling depression.
Furthermore, a randomized controlled trial from 2016 shows that vitamin D supplementation in expectant mothers leads to reduced perinatal and postnatal depression (44).
While the best source of vitamin D is natural sunshine, oily fish, mushrooms, and eggs are all good dietary sources.
Researchers estimate that the global prevalence of zinc deficiency stands at 17.3% (45).
In particular, low concentrations of zinc have a strong connection with signs of depression (48).
The best foods to increase our dietary intake of zinc include oysters, lamb, and meat and seafood in general.
9. Vitamin C
With studies on vitamin C and depression only emerging in recent years, the potential benefits for mental health are little known.
However, studies suggest that insufficient vitamin C status correlates with increased risk of depression (51).
A randomized trial testing the impact of supplementary ascorbic acid (vitamin C) showed that it significantly reduces anxiety levels in depression patients (52).
Additionally, combining a higher vitamin C intake with antidepressants “significantly decreased the Hamilton depression rating scale” compared to antidepressants alone (53).
Leafy greens and citrus fruits are a great source of dietary vitamin C.
10. B Vitamins
However, these dangers are not exclusive to vegans; anyone not consuming enough B vitamins is at risk.
A randomized controlled trial featuring 199 depression patients showed that vitamin B12 supplementation significantly improves symptoms of depression (56).
The best sources of B vitamins are animal foods; all types of meat are particularly good options.
How We Can Fight Depression With Nutrition
First of all, it’s important to note that no diet replaces the need for conventional depression treatments. Depression can be a severe condition which requires support from medical experts.
However, by focusing on a nutrient-dense dietary plan, we can give ourselves the best chance to help prevent/fight depression.
An anti-depression diet should feature whole food sources of meat, fish, and vegetables to ensure sufficient intake of critical nutrients like omega-3, B vitamins, and amino acids.
Additionally, we should focus on limiting the nutrients which increase the risk for depression. For instance, sugar and refined carbohydrates increase the risk of depression in numerous studies (57, 58, 59).
Interestingly, these foods are also known to cause inflammation in the body (60).
Crippling depression is a condition which devastates lives, so it’s important to be aware of how we can fight it.
As part of this, nutritional strategies can play a significant role alongside conventional treatments.
Finally, it’s important to remember that our whole lifestyle is important and good health isn’t solely a healthy diet.
A good diet coupled with sufficient sleep, stress-free life, and frequent exercise is the best way to protect against depression.