[Last updated 25th June, 2018]
Depression is estimated to affect 350 million people worldwide.
Traditionally it’s treated with medication, but new evidence suggests certain foods and nutrients may be highly influential.
This could be revolutionary considering less than half of those affected receive formal medical treatment.
This article looks at what foods and nutrients may help, particularly for dealing with major depression.
What is Depression and Major Depression?
Depression is a complex mental health disorder usually characterised by low mood and avoiding usual activities.
Typical symptoms include sadness, anxiety, loss of appetite, low mood, and lack of interest in previously pleasurable activities. The severity of these symptoms determines how the depression is categorised.
Major Depressive Disorder (MDD) (also called major depression, clinical depression or severe depression) is the diagnosis after at least two weeks of chronic low mood.
This condition is what most are referring to when speaking of depression, and will now be referred to as depression in this article. This is a nice introductory video:
Scientists have long thought depression was simply a chemical imbalance in the brain, or something that was strictly emotionally-rooted. But the cause is much more complex, and is likely a combination of genetic, psychological, physiological and inflammatory factors.
The newly discovered link between depression and low-grade inflammation is of particular interest, especially from a nutrition perspective (3).
Summary: Depression is a complex mental health disorder, known as Major Depressive Disorder if symptoms are long-term. It’s thought to be caused by a complex combination of factors.
Depression Medication is Still Fundamental to Treatment
Although not perfect, pharmaceutical medications are usually fundamental for treating severe depression.
You should certainly not stop taking your medications without first speaking with your doctor.
However, new research indicates certain dietary changes may be effective alongside medical treatment. Specifically, some forms of nutrition supplementation appear to improve the effectiveness of antidepressants.
This could also have implications for treating children and adolescents, as well as milder forms of depression, where antidepressants are not always suitable.
Summary: Severe depression is primarily treated with medications, and they are still important.
Diet Patterns vs Isolated Nutrients
Of the research into depression and diet, very few studies have investigated how overall dietary patterns influence depression.
Diets high in fruits and vegetables and fish (characteristic of the Mediterranean diet) are linked to the lowest risk of depression. However all the evidence is observational, which does not allow researchers to make strong conclusions (4, 5, 6).
Therefore at this point there is no specific diet or eating pattern proven to treat depression.
Just eat a lot of fruits, vegetables and fish, and make sure you follow an eating pattern you can stick to for 1-2 years at the very least.
Summary: There is currently no particular eating pattern shown to benefit depression, at least from a scientific standpoint.
Foods, Supplements and Natural Remedies for Depression
Most research into natural remedies for depression has looked at isolated nutrients in the form of supplements.
Some are extremely promising, particularly when used alongside medications and formal therapy.
As always, speak with your doctor before trying anything new.
St. John’s Wort (Hypericum Perforatum) and Depression
St. John’s Wort is a medicinal herb with powerful anti-inflammatory and antidepressant properties.
A major Cochrane review including 5,489 patients with major depression concluded that St. John’s Wort extract (7):
- Is superior to placebo in patients with major depression
- Is similarly effective as standard antidepressants (SSRIs and TCAs)
- Has fewer side effects than standard antidepressants, although there are some non-responders.
It’s actually odd this is not more well-known and appreciated.
The caveat is that St. John’s Wort should not be taken alongside antidepressants. This is because it’s known to interact with many medications, particularly those for serotonin signalling in the brain (8, 9).
Therefore it’s more of a potential alternative to antidepressants, rather than a complementary treatment.
The majority of studies used dosages of around 900 mg daily, which should be split into three 300 mg doses.
Zinc and Depression
Zinc is an essential mineral that appears to interact with neurons in the brain.
Those with depression tend to have lower zinc levels than normal (10).
Studies show that zinc supplementation alongside antidepressants can help reduce depressive symptoms in as little as 12 weeks (11).
In fact, zinc therapy on its own may even improve symptoms, at least in overweight/obese people with depression (12).
It seems an elemental zinc dosage of 25 – 30 mg per day is best. That is equivalent to supplementing either:
- 75 mg of zinc citrate
- 110 mg of zinc sulfate
- 170 mg of zinc gluconate
- 120 mg of monomethionine
It’s also recommended to eat a variety of zinc-rich foods including:
- Oysters and shellfish
- Chicken and beef
- Legumes, seeds and nuts
Fish Oil and Depression
The effective dosage is thought to be up to 2,200 mg daily of EPA. This is high and must be supplemented, although eating fatty fish itself is strongly recommended too.
Creatine Monohydrate and Depression
Creatine is a molecule that helps provide energy to all cells in the body, including the brain.
It’s one of the safest and most well-researched supplements around, most commonly used by athletes to improve physical performance.
One well-designed study was able to match the efficacy of SSRI antidepressants after just 2 weeks of creatine supplementation in women with major depression (21).
It’s suspected that creatine is more useful in women as they tend to have lower levels than men. Just note it does cause additional water retention, which leads to slight weight gain.
At least 5 grams per day appears to be the most effective dosage.
Saffron and Depression
Saffron is the world’s most expensive spice.
Saffron is best taken twice daily in 15 mg doses. A more inexpensive method is to use saffron petal extract (instead of the regular stem).
Less Proven Supplements
There are numerous other nutrients and supplements linked to depression treatment.
However they are either less effective or backed by fewer well-designed studies.
Summary: St. John’s Wort appears to be a useful alternative for those unwilling or unable to use regular antidepressants. Zinc and fish oil supplementation seem to enhance the effectiveness of antidepressants, while creatine and saffron may also be effective.
Depression and Gut Bacteria (Microbiota)
Although antidepressants and supplements help to manage symptoms of depression, do they treat the cause?
Insulin corrects a measurable imbalance in diabetics, and thyroid hormone corrects a measurable imbalance in hypothyroid patients.
But SSRIs, for example, do not correct any underlying problem. Many argue they are simply a band-aid treatment, which is why they don’t work for all patients.
An emerging theory is that the balance of our gut bacteria (microbiota) largely influences brain development, mood and behaviour. Therefore, our gut health should be the primary focus of depression treatment.
In fact, only about 10% of the chemical serotonin – the “happy hormone” – is actually made in the brain. This is the chemical that SSRI antidepressants are designed to amplify.
The remaining 90% is made in the digestive tract… the gut (33).
Bacteria can communicate with the brain via activating neural pathways and central nervous system signaling systems. This is known as the Gut-Brain Axis, and seems to be influenced by low-grade inflammation in the gut (3, 27, 28, 29).
In one study, just by examining the bacteria from fecal swabs, researchers were able to determine the patients with and without depression with at least 97% accuracy (30).
These so-called “Psychobiotics” could one day be the primary form of depression treatment. But I don’t yet feel comfortable recommending probiotics as a reliable option until more is understood.
As you can see, addressing any imbalances or intentionally “tweaking” the microbiota opens a whole new channel for interacting with the brain. It puts nutrition and diet at the forefront of physiologically treating depression, at least, theoretically.
Summary: The balance of our gut bacteria (microbiota) appears to influence brain health and behaviour via the Gut-Brain Axis. Altering or correcting any imbalances with diet could help treat some causes of depression, at least in theory.
Summary of Recommendations
To summarise the above recommendations:
- Antidepressant medications are still very important. Do not change anything without speaking with your doctor first.
- It seems beneficial to eat a nutrient dense diet that includes vegetables, fruits, fish, nuts and seeds at least once per day.
- However, there is no particular eating pattern proven to help treat depression. Therefore don’t follow an extreme eating pattern you don’t enjoy. If you can’t see yourself following it in 1 or 2 years, then it’s not right.
- Supplements to take alongside antidepressant medications include zinc and fish oil, perhaps creatine too. St. John’s Wort appears an extremely useful alternative if antidepressants are not an option.
- Identify any nutrient deficiencies and correct those, particularly folate (folic acid or l-methylfolate), vitamin D and zinc.
- Probiotics could very well help, but we don’t know what strains, nor what dosage.
Of course treating depression is multifactorial, with diet only one (giant) piece of the puzzle.
Other important factors include mindfulness meditation or cognitive behavioural therapy with a licensed psychologist, reducing stress with more time outdoors, improving sleep quality, and staying physically active.
Don’t Deal With Depression On Your Own
You don’t have to deal with depression alone.
In most instances speaking with others who understand how you feel can be a tremendous help. Whether that is talking with a mental health care professional, or with peers who feel the same way as you.
An informal starting point to express yourself and ask questions (where you can remain anonymous) is this reddit forum.