The connection between physical and mental health is no news! As early as the second century AD, the Roman poet Juvenal advocated “mens sana in corpore sano”, meaning “a healthy mind in a healthy body”. While this Latin quote is well-known, its veracity has only been established in the past few decades thanks to research on the side effects brought about by the use of different types of medication, namely the depletion of nutrients and its consequences. This article identifies 3 essential nutrients that are implicated in the development of depression. However, this list is not exhaustive and should not be interpreted as a cure for depression as much as a preventive measure against it.
Nutrient 1: B Vitamins
Three of the eight B vitamins have consistently been associated to depression: these are vitamin B6, B9 and B12 which will are treated separately below.
The active component of vitamin B6, pyridoxal 5′-phosphate (PLP) plays a role in the metabolism of amino acids, lipids and glucose and in the synthesis of neurotransmitters such as serotonin and dopamine. In particular, vitamin B6 is necessary for converting tryptophan into serotonin. Research has shown that vitamin B6 deficiency can lead to the development of depression. Some of the foods with the richest concentration of vitamin B6 are sunflower seeds, pistachio nuts, tuna and other oily fish, turkey and chicken, lean pork, prunes and lean beef.
Vitamin B9, also known as folic acid or folate, is used by the body to synthesise and repair DNA, to make RNA and to produce neurotransmitters which are necessary for maintaining mental health. Folic acid also facilitates recovery from a number of psychiatric illnesses. Research has shown that there is a link between folic acid and depression: a large-scale study found lower levels of folic acid in people with depression compared to a healthy control group. However, other research suggests that this link might be indirect: folic acid deficiency might lead to decreased levels of S-adenosyl methionine (SAMe), which in turn causes the symptoms of depression. There might also be gender differences in the role that folic acid plays in depression as in a study the same dose of folic acid reduced symptoms in women but not in men for whom a much greater dose was needed to experience any benefits. Even though the link between folic acid and depression is unclear, enough research indicates that low levels of folic acid might be a risk factor in the development of depression. Folate can be found in lentils, beans, spinach, asparagus and broccoli just to mention a few. For a complete list of foods rich in folic acid, click here.
Vitamin B12 or cobalamin plays a key role in the normal functioning of the nervous system and in the metabolism of fatty acids and amino acids. Vitamin B12 deficiency, which is more likely to develop in elderly people than in the younger population, has been associated to depression symptoms. On the other hand, people who have high levels of vitamin B12 seem to respond better to treatment. All animal derived foods, such as poultry, dairy products, eggs,fish and shellfish, meat and especially liver, are rich in vitamin B12.
Given the importance of these B vitamins for the wellbeing and functioning of the nervous system, a balanced diet including a variety of foods rich in B vitamins should reduce the chances of developing depression associated with B vitamin deficiency.
Nutrient 2: Amino Acids
The amino acids phenylalanine and tryptophan in particular play a crucial role in the synthesis of neurotransmitters.
Phenylalanine is found in most meat and fish and in leafy greens, such as spinach. The body converts phenylalanine into tyrosine, another amino acid used for the production of neurotransmitters involved in mood, such as norepinephrine. Phenylalanine deficiency is known to result in depression like symptoms. People affected by depression reported improved mood after being treated with phenylalanine, but more research is needed to establish the effectiveness of this amino-acid in treating depression.
Tryptophan is essential for the production of serotonin, a neurotransmitter implicated in depression. Research has shown increased serotonin levels as a consequence of tryptophan intake, indicating a very clear link between tryptophan deficiency and depression. As well as being present in most meat, fish and dairy products, tryptophan is also found in chocolate, bananas and peanuts.
Nutrient 3: OMEGA-3 Fatty Acid
Omega-3 fatty acid is essential for metabolic functions in the body and is found in walnuts, fish oils and flaxseed oils among other foods. Research has shown that Omega-3 supplements were useful in reducing depressive symptoms when combined with other medication.
Hopefully this article has stressed the importance of including certain nutrients to obtain a well-balanced diet in order to decrease risk factors in developing depression. Worth mentioning is the fact that one’s lifestyle can lead to the depletion of some nutrients even though these are present in one’s diet. For example, drinking coffee and alcohol can lead to vitamin B complex depletion. Therefore, a well-balanced diet should be integrated with food supplements to counterbalance lifestyle factors. Together with the food supplements mentioned so far, some natural remedies against depression are described below.
Some natural remedies to prevent Depression
Research has shown that the plant rhodiola rosea reduces fatigue and increases resilience to stress by boosting both the nervous and the immune systems. But how does it do it? Two of rhodiola rosea’s active ingredients, rosavin and salidroside, facilitate the transport of tryptophan, which is a serotonin precursor (see above).
Another natural remedy is S-adenosyl methionine (SAMe) which is important in the production of neurotransmitters and is an effective mood booster, can be easily found in the form of dietary supplements.
St. John’s Wort has also been used effectively to treat mild to moderate depression.