THERE ARE 4.5 million depressed Filipinos, the highest number in Southeast Asia. Unfortunately, according to the World Health Organization, only one out of three who suffer from depression will see a counselor. One-third of this depressed group will not even be aware of their condition. However, thousands of them can be helped by changing their diet.
There are many causes of depression, like family predisposition to the ailment, chronic stress or intrigue in the workplace, poverty, family discord, breakup with a girlfriend or boyfriend, inability to pay tuition, frequent argument with a neighbor, etc. But you will be surprised to know that new studies are emerging linking diet to depression.
In the past two decades, data have accumulated showing that certain foods bring about mental wellbeing. Fish and other sources of omega-3 fatty acid might help protect us from psychosis and depression, green tea and antioxidants may help reduce early onset of dementia, and fermented food like yogurt, pickles and sauerkraut may ease anxiety.
What I am excited about in this new idea of diet boosting brain function is that in the near future, physicians will be writing prescriptions for patients to eat more fish, drink more green tea, eat fruits and vegetables often, reduce consumption of meat and processed food, and shun soft drinks.
In 2011, a group of public health experts headed by Almudena Sanchez-Villegas of University of Las Palmas de Gran Canaria in Spain began a study of the Mediterranean diet of 12,000 healthy Spaniards in a course of six years. This diet is composed of fruits, vegetables, nuts, fish, and whole grain, lean meat in moderation, and some red wine. The researchers found that people who are on a Mediterranean diet had lesser incidence of depression by about 30 percent.
The first scientist who proposed that the Western diet can lead to depression and anxiety is Felice Jacka of University of Melbourne in Australia. And more recently, she found that poor diet can lead to brain shrinkage. In a report in September 2015, she and her colleagues said older adults who were on a Western diet for four years not only suffered mood disorders but also had a smaller-sized left hippocampus as seen in magnetic resonance imaging. This part of the brain is critically involved in memory formation. Jacka focused on this brain part because animal studies also showed similar anatomical findings.
Other scientists have shown that when the diet is high in sugar, an inflammatory reaction occurs in tissues like the brain. Ordinarily, inflammation is a part of a natural reaction of the body to fend off infection and encourage healing. However, when inflammation is in high gear and chronic, it can trigger metabolic changes leading to impaired brain function, as manifested by the signs and symptoms of depression, bipolar disorder, schizophrenia, and Alzheimer’s disease.
Two reports called meta-analysis, which is a collection of 53 similar researches from 2010 to 2012, showed elevated blood markers of inflammations in depressed and schizophrenic patients.
Jacka’s study also showed that healthy traditional diets from the Mediterranean, Japan and Scandinavia tend not to support inflammation in the body. These diets are best for brain cells and lead to better mental health. “But consistently the data show that the main constituents of a healthy brain diet include fruits, vegetables, legumes, nuts, fish, lean meat, and healthy fats such as olive oil,” Jacka said.
In the summer of 2015, Christine Barul and her colleagues at University of Bordeaux in France found that the Mediterranean diet may actually preserve the connections between brain cells, called synapses.
Last September, nutritional epidemiologist Martha Morris of Rush University and her coworkers reported that the MIND diet—a combination of Mediterranean and high-nutrient, low-salt diets—slowed cognitive decline and helped reduce Alzheimer’s disease. They tested 950 seniors who followed the MIND diet for about five years, and the scores matched those who were 7.5 years younger.
Michael Crawford, a psychiatrist at Imperial College of London, copublished a paper stating that the brain is dependent on fatty acid DHA (docosahexaenoic acid), which is mostly found in shellfish and cold-water fish. The brain is 60 percent fat, and DHA is the dominant nutrient that keeps it healthy. For more than 40 years, Crawford has argued that mental disorders are increasing because of the shift to a land-based diet.
In 2014, a 23-year-old student, Tom Spector, experimented on himself by eating only fast-food hamburger, french fries, and soda for 10 days. With this diet he became lethargic and feeling down—a result of an inflammatory reaction in the walls of the gut which produced more serotonin, whose metabolic precursor, tryptophan, is involved in generating neurotoxic chemicals linked with depression, schizophrenia and Alzheimer’s.
To keep a healthy brain, we should eat more fish, fruits, vegetables, legumes, nuts and olive oil, and drastically reduce consumption of meat, trans fats, and sodas. Add exercise to this menu, and you’ll have a happier, smarter and longer life.
Dr. Leonardo L. Leonidas (nonieleonidas68@ gmail.com) retired in 2008 as assistant clinical professor in pediatrics from Boston’s Tufts University School of Medicine, where he was recognized with a Distinguished Career in Teaching Award in 2009. He is a 1968 graduate of the University of the Philippines College of Medicine and now spends some of his time in the province of Aklan.