Depression is one of the leading mental illnesses around the world. A global study by the World Health Organization (WHO) found that 322 million people were affected by depression in 2017, with almost half this number from Southeast Asia and Oceania, including India and China. For individuals affected by depression, daily activities nearly come to a halt due to symptoms like low concentration, fatigue, disturbed sleep, and feelings of hopelessness. These conditions impact health, relationships and work performance, resulting in significant social and economic cost ramifications. Studies project that by 2030, depression will be one of the leading causes of loss in productive years in an individual’s life.
Although a mental health disorder, depression may be both the cause and effect of physical health concerns. Presently, researchers are investigating the connection between nutrition and depression. Findings suggest that deficiencies in certain nutrients or poor food choices may impair the production of chemicals in the brain, such as serotonin and dopamine, responsible for feelings of pleasure and happiness. These studies are clubbed under the emerging field of ‘nutritional psychiatry’, examining the connections between what we eat and how we feel.
Studies have highlighted that specific food groups and nutrients play a role in the onset and duration of depression. Foods rich in carbohydrates and protein may promote feelings of well being and happiness. High consumption of vegetables, fruits, and fish may reduce the risk of depression, while refined sugar, soda, and junk food may increase the risk of developing depression. Low consumption of essential fatty acids, vitamins, and minerals may drive depressive tendencies in individuals. The bacteria in our gut also have a role to play.
Traditional diets such as Japanese and Mediterranean diets have more vegetables and fruits, probiotics, unprocessed foods, fish and seafood, and small amounts of dairy and red meat. On the other hand, fast food, sugar, unhealthy fats, and high levels of processed, refined food, and red meat dominate Western diets, which lack vitamins, minerals, and healthy fat.
Studies comparing different diets claim that the individuals following a traditional diet are less likely to develop depression. Moreover, diets rich in refined starch, high fat, and processed meat may promote inflammation. Obesity causes an increase in the amount and size of fat cells, which can cut off blood supply to other cells, causing cell death. It causes the immune system to release immune cells, and an increase in the number of fat cells and immune cells leads to inflammation. The body’s immune system treats inflammation as ‘sickness’, triggering fatigue, low appetite, low attention, and poor memory. When these behaviours continue for long periods, they can lead to the development of depression. Individuals who are overweight or obese are more prone to mental health concerns arising out of inflammation.
The ongoing COVID-19 pandemic has increased the rate of mental illnesses amongst Indians. “Some of the reasons for this can be low physical activity, high consumption of packaged foods rich in sugars, salt, saturated fat, and poor dietary patterns,” says Preeti Khanna. She is a senior research fellow at the Department of Food and Nutrition, Institute of Home Economics at Delhi University.
Recent research suggests that in individuals with weak immune systems, stress and lack of adequate nutrition may lead the immune system to release lower amounts of anti-inflammatory substances and higher levels of chemicals that promote inflammation. As a result, the serotonin levels decrease, leading individuals to show symptoms of depression.
“Malnourished individuals are vulnerable because of their weak immune systems, and often there is a stress-induced weakening of the immune system as well,” says Dr Sylvia Fernandez Rao. She is an assistant director at the Behavioural Science Unit at the National Institute of Nutrition, Hyderabad.
Dietary interventions
Psychiatrists have explored changing the diets of individuals to help them tide over depressive symptoms. “Individuals may be encouraged to increase consumption of traditional Indian diets that involve whole grains and multi-grains along with healthy fats,” says Preeti. Eating traditional Indian diets rich in grains such as ragi, maize, jowar, lentils and pulses, healthy fats such as ghee, and locally sourced fruits and vegetables, and avoiding packaged and processed food may benefit those suffering from depression.
Dr Gurjinder Kaur Brar, a medical anthropologist and a mental health professional, opines that increased consumption of nutrients such as folate, B12, and zinc, whose significant sources are fish and seafood, does help. Since a majority of Indians are vegetarian, our diets are at times deficient in necessary nutrients. While a vegetarian diet ensures no red meat or processed meat, it also falls short of healthy fats like omega 3, and beneficial minerals like zinc and selenium, she believes, pointing out that food with added nutrients and supplements may help alleviate depression.
In rural India, those in poor socio-economic conditions already bear the brunt of malnutrition. Fruits, green leafy vegetables, and animal products are expensive and unaffordable for many. Due to long-held gender biases and inequalities, women tend to be more deprived of nutritionally-rich food.
“In India, nutritional deficiencies are primarily seen amongst girls rather than boys, and amongst those who follow vegetarian diets,” adds Gurjinder. The social, economic, and family dynamics in rural households related to substance abuse and domestic violence further compound the effect on the mental well-being of people.
Bringing a policy-level change
While nutrition-based interventions can be aimed at individuals, systematic changes in food and nutrition policies are necessary too. “There is enough available evidence for prioritising nutrition as an effective, low-cost preventive measure for poor mental well-being,” asserts Gurjinder. To extend increased production to food products like dairy, and fresh fruit and vegetables, the National Food Security Mission was launched by the government in 2007, aiming to provide access to nutritious food for everyone.
However, recent government data shows that child nutrition has declined in many states in the last few years. Critical reviews on food policy highlight that India has struggled to curb undernutrition. While many factors cause undernutrition, food security is the primary cause. Initiatives like the Public Distribution System (PDS), Targeted Public Distribution System (TPDS), and the National Food Security Act (NFSA) have failed to increase the access to nutritious food significantly. Setting up new institutions under the NFSA has proved costlier than previously anticipated, and states have had to bear some amount of this expense.
“India is currently facing the dual burden of public health problems –– mental health disorders and malnutrition,” says Preeti. An increased awareness between nutrition and mental well-being may help individuals supplement their psychotherapy programs with nutritional food. However, with little research on nutritional psychiatry in India, pinpointing nutrition-based scientific and policy strategies to address depression amongst Indians may not be possible. Experts call for more long-term data and research in this field.