Lowered mood is one of the major symptoms of depression, a widespread affective disorder that affects approximately 20% of the world’s population. Although depression is caused by many factors, nutrition can play a key role in its onset as well as its severity and duration. It is not yet clear whether poor nutrition causes nutrient deficiencies as a symptom of depression, or if primary nutrient deficiencies cause depression and its symptoms.
Serotonin is a neurotransmitter synthetized in the body from the essential amino acid tryptophan, and impacts your mood, behavior, temperature, sleep cycle, and appetite. Serotonin is also used to make melatonin, a hormone that helps to control your sleep and wake cycles. When serotonin levels are high, your mood, sleep patterns, and pain tolerance increase. Low serotonin levels are associated with poor memory and depressed mood. Tryptophan, the serotonin precursor, cannot be synthetized in the body: it must be taken in through diet, supplements, or medication. Tryptophan is an essential amino acid that is found in meats, dairy, fruits, and seeds. Levels of plasma tryptophan are determined by a balance between dietary intakes versus utilization.
Studies assessing the diet of people suffering from depression have found that most of them make poor food choices and select foods that may actually contribute to depression. Many of the easily noticeable food patterns that precede depression are the same as those that occur during depression, such as poor appetite, nutrient deficiencies, skipping meals, and a dominant desire for sweet foods.
Nutrient Deficiencies and Depression
The most common nutritional deficiencies seen in patients with mental disorders are deficiencies of omega–3 fatty acids, B vitamins, minerals, and amino acids that are precursors to neurotransmitters (such as amino acid tyrosine and tryptophan). Daily consumption of omega-3 fatty acid supplements containing 1.5-2 g of EPA have been shown to stimulate mood elevation.
Diets low in carbohydrate tend to precipitate depression. This is because the production of brain chemicals serotonin and tryptophan, which promote the feeling of wellbeing, is triggered by carbohydrate-rich foods. It is suggested that low glycemic index (GI) foods such as some fruits and vegetables, whole grains, pasta, etc. are more likely to provide a moderate but lasting effect on brain chemistry, mood, and energy level than the high GI foods - primarily sweets - that provide immediate but temporary relief.
A diet high in quality proteins contains all the essential amino acids. A lack of the amino acids tyrosine and tryptophan may affect the synthesis of neurotransmitters, which may be associated with low mood and aggression. Food sources of tyrosine include cheese, soybeans, beef, lamb, pork, fish, chicken, nuts, seeds, eggs, dairy, beans, and whole grains. Food sources of tryptophan include chocolate, oats, dried dates, milk, yogurt, cottage cheese, red meat, eggs, fish, poultry, sesame, chickpeas, almonds, sunflower seeds, pumpkin seeds, buckwheat, spirulina, and peanuts.
Omega-3 Fatty Acids
Increasing evidence from epidemiological, laboratory, and randomized placebo-controlled trials suggests that a deficiency of dietary n-3 PUFAs may contribute to the development of mood disorders. Some studies suggest that omega-3 fatty acids may be beneficial in the treatment of mild to moderate depression in adults, but more research is needed.
Depressive symptoms are the most common neuropsychiatric manifestation of folate deficiency. According to studies, supplementation of B vitamins may improve mood in adults. This mood improvement was particularly associated with improved vitamin B2 and B6 status in general, and with B1 status in women.
Higher levels of tryptophan are related to improved mood. This may happen indirectly, since we get tryptophan from foods and store it in our bodies. After a meal or snack with carbohydrates, the body uses the tryptophan stores to increase its serotonin levels. A snack with 30 grams of carbs just before bed may improve sleep quality. If you are diabetic, ask your doctor before you try this.
5 strategies to increase your tryptophan levels without medicine:
If you have more questions or concerns regarding this topic, come see me to my desk. I will be glad to answer your concerns.
Have a wonderful weekend!
Karen Alexander, BSNC, MSCN