Depression is defined as a low mood status with aversion to activities that have the potential of affecting the feelings, the behavior and the physical wellbeing of a person. People who are depressed may have a feeling of sadness, emptiness, helplessness, guilty, irritability, restlessness, hopeless and worthless. Such people usually have lost interest in some activities which they once regarded as very pleasurable to them, they may lose appetite or eat a lot than before, they cannot concentrate properly, have difficulties in remembering something and difficulties in making of decisions. Other signs and symptoms of depression are insomnia, sleeping a lot; feeling like the person is weak and digestive problems which do not respond to treatment. Depression is associated with changes in the brain substances which the cells use in their communication. These substances are norepinephrine, dopamine and serotonin. The levels of the above neurotransmitters are influenced by diet, hormonal changes, genetics, physical illnesses, medications, light cycles, social circumstances, brain injuries and medications among others (Kennaway, 2010, p. 5).
According to Artemis P. et al, (2009, p. 56), the brain needs some critical nutrients to be readily available for it to function properly. The deficiency of the important nutrients may lead to the inability of the brain to less alert and develop suboptimal cognition. However, this deficiency may manifest as more serious psychiatric disorders such as suicide, impulsiveness and depression in the affected individual. Thus, depression can result from nutrition deficits in a person. The human brain is composed primarily of lipids and fats which form at least sixty percent (60%) of the total net-weight. Some examples of the fats found in the brain are: Eicosapentaenoic acid (EPA), docesahexaenoic acid (DHA) and docosapentanaenoic acid (DPA). DHA (docesahexaenoic acid) is very concentrated in the membranes of the neural cells, forming at least fourteen percent of the fatty acids in a neural membrane (Kennaway, 2010, p. 11). According to Artemis P. et al, (2009, p. 76), the dietary deficits of the above fatty acids can cause psychiatric illness in the following mechanisms: The neurons are not able to migrate, connect, apoptosis in the right time and arborization of the dendrites. This leads to permanent disruption of the pathways of neurons which regulate the behavior of a person. Secondly, the deficiency of these fats leads to depletion of the levels of dopamine and serotonin in the brain. In animal models, the deficiency of the fatty acid in the brain has been shown to reduce the amount of serotonin and dopamine by at least fifty percent (50 %). Lastly, the deficiency leads to a process of inflammation and hypothalamic pituitary adrenal axis dysregulation in such persons.
Nutrition and Depression
Rezende, et al. (2009, p. 618), carried out a study to establish the relationship between depression and nutrition and other factors like aging and hematologic values among the institutionalized patients. In the study, it was found out that depression was related to worsening status of nutrition in an individual. People who had a poor nutritional status were more likely to be depressed than the rest of the population (Kennaway, 2010, p. 13). According to the study, geriatric depression scale was negatively proportional to the mini-nutritional assessment scores. If the mini-nutritional assessment score was high, the person was likely to have a low score on the geriatric depression scale. This shows that in the human population, poor nutrition can lead to changes in the brain which will affect the mood of a person. Poor nutrition is associated with lack of essential nutrients required for the proper functioning of the brain and thus their depletion secondary to malnutrition can lead to depression.
Effects of Poor feeding habits and Parenting on development of Depression
People who have poor eating habits or those who have additional nutritional requirements have been found to suffer from depression (Kennaway, 2010, p. 14). People such as parenting mothers are more likely to suffer from depression disorder than other ladies who are not parenting. A study carried out by Hurley, et al, (2008, p. 800) proved this knowledge. It was found that pregnant or breastfeeding mothers were more likely to suffer from depression as compared to their counterparts who are not. In addition, the study also established that those people who had poor eating habits were more likely to suffer from depression. This shows that there is some relationship between the nutrient intake and nutritional needs with development of depression in a person. If there are fewer intakes of nutrients for example in people with poor eating habits, there is a high possibility of development of depression. On the same note, if the demands for nutrients in a person are many, for example in pregnant or breastfeeding mothers, the brain is not likely to get enough. As a result, there is a high possibility of deficiency of essential nutrients in that mother. This shows that the amount of nutrients available in the body is important in the development of depression (Hurley, et al, 2008, p. 801).
Role of Inflammation and Fatty Acids on Depression
In patients who do not respond to the depression treatment, it has been established that the use of polyunsaturated fatty acids reduces the symptoms (Hurley, et al, 2008, p. 802). This raises the question as to whether inflammatory cytokines and fatty acids may play a role in the development of depression or in its cure. Dinan, et al. (2009, p. 472) studied this relationship and established that in both non responders and responders of treatment, depression patients had elevated arachdonic acid levels in blood. However, eicosapentaenoic acid was elevated in responders more than in non-responders. This indicated that responders who have been treated, have the levels of these acids normalized while in non responders, there is a deficiency of the fatty acid which may be the contributing factor to the failure of the patient to respond to the treatment of depression. This shows the importance of the fatty acids, which are also involved in inflammatory processes in the patho-physiology and treatment of depression in patients who are non-responders (Hurley, et al, 2008, p. 803).
Janice, (2010, p. 5), states that an eiconasanoid derivative from arachidonic increases the production of IL-1 (Interleukin 1and TNF (tumor necrosis factor) alpha which are pro-inflammatory factors which act as prostaglandin precursors. This fatty acid is derived from sources such as sunflower, corn and vegetable oil. However, the fatty acids derived from fish, wheat germ and dietary supplements can reduce the production of eicosanoids derived from arachidonic acid thus reduction the increased production of the inflammatory mediators. The author argues that there is a link between inflammation and depression. Therefore, according to the author, use of fatty acids derived from fish and food supplements can be helpful in people who are suffering from depression. The fish fatty acids will compete with the other fatty acids in the pathway for prostaglandins and thus reduce the amount of prostaglandin (Hurley, et al, 2008, p. 804). As a result, there will be less inflammatory mediators because of decreased prostaglandins. Reduced inflammatory mediators will lead to reduced inflammation and thus reduced depression. Therefore, these fatty acids can be used in the treatment of the non-responders of depression.
However, in another research by Makrides, et al (2010, p. 1675), the administration of docosahexaenoic acid to pregnant mothers before mod trimester did not reduce the occurrence of post partum depression. The percentage of the ladies who developed post partum depression was not significantly different between the ladies who were given the fatty acid and their controls. Thus, the claim that the administration of these fatty acids reduces post partum depression is not true, according to the study. It thus questions the befit of use of docosahexaenoic acid on mothers who are pregnant in the prevention of depression after they give birth (Makrides, 2010, 1677).
Vitamin D deficiency and Depression
Ganji, et al., (2010, p. 2) researched on the impact of vitamin D deficiency on people and how it affects depression. They compared depression in two groups, those with vitamin D deficiency and those without. The research found out that the possibility of having depression in a person with vitamin D deficiency is more as compared to those without the vitamin deficiency. The association between people with vitamin D deficiency and depression is very common in the United States according to this article which indicates a possible link between the two (Ganji, et al., 2010, p. 4). However, the study did not establish how the deficiency of vitamin D led to increased chances of developing depression. The study therefore suggested that people who have vitamin D deficiency should not be ignored but urgent measures should be taken to avoid a situation where the deficiency leads to depression in such people (Ganji, et al., 2010, p. 6).
Obesity and Depression
There is a relationship between obesity and depression especially in ladies (Ganji, et al., 2010, p. 6). Ladies who are obesity tend to be depressed as compared to others who are not obese. In the normal population, majority of depressed ladies will be obese. The reason for this has not been a subject of debate. There have been some researchers who argue that the cause of depression in such ladies is because of the social effect of the obesity. Others argue that obesity leads to some biochemical reactions in the brain which make those ladies be depressed. Therefore, in the prevention of depression, nutritional guidance on obese people is needed.
Nutrition has played an important role in the causation and the treatment of depression. People who have a poor nutritional status have been found to suffer more from depression. The administration of some fats in people suffering from depression has proved to be an effective treatment of depression. Vitamin D deficiency also leads to increased chances of developing depression. Therefore, there is a correlation between nutrition and depression. A good nutritional standard will be inversely related to development of depression.