A number of recent studies and articles have discussed the effectiveness of diet in treating or preventing depression with the main conclusion that yes, it helps. Now an observational study (that will be presented in April) found that elderly people following the DASH diet most closely were 11% less likely to become depressed over time than those that did not.
Researchers studying 964 elderly participants over six and a half years found that those who followed the DASH diet, which emphasizes whole grains, fruits, and vegetables, had lower rates of depression, while those who ate a traditional Western diet were more prone to depression. The DASH (Dietary Approaches to Stop Hypertension) diet also emphasizes low sodium (salt) to lower blood pressure, as well as foods rich in nutrients (such as potassium, calcium, and magnesium) that are thought to lower blood pressure.
The study's lead author L. J. Cherian (at Rush Medical Center in Chicago) said that "we need to view food as medicine”. Yes. Eating more fruits and vegetables, whole grains, legumes, seeds, nuts have many health benefits (such as cardiovascular benefits, improving the gut microbes) - a win-win. From Science Daily:
Diet shown to reduce stroke risk may also reduce risk of depression
People who eat vegetables, fruit and whole grains may have lower rates of depression over time, according to a preliminary study that will be presented at the American Academy of Neurology's 70th Annual Meeting in Los Angeles, April 21 to 27, 2018. The study found that people whose diets adhered more closely to the Dietary Approaches to Stop Hypertension (DASH) diet were less likely to develop depression than people who did not closely follow the diet. In addition to fruit and vegetables, the DASH diet recommends fat-free or low-fat dairy products and limits foods that are high in saturated fats and sugar. Studies have shown health benefits such as lowering high blood pressure and bad cholesterol (LDL), along with lowering body weight.
"Depression is common in older adults and more frequent in people with memory problems, vascular risk factors such as high blood pressure or high cholesterol, or people who have had a stroke," said study author Laurel Cherian, MD, of Rush University Medical Center in Chicago and a member of the American Academy of Neurology. "Making a lifestyle change such as changing your diet is often preferred over taking medications, so we wanted to see if diet could be an effective way to reduce the risk of depression."
For the study, 964 participants with an average age of 81 were evaluated yearly for an average of six-and-a-half years. They were monitored for symptoms of depression such as being bothered by things that usually didn't affect them and feeling hopeless about the future. They also filled out questionnaires about how often they ate various foods, and the researchers looked at how closely the participants' diets followed diets such as the DASH diet, Mediterranean diet and the traditional Western diet.
Participants were divided into three groups based on how closely they adhered to the diets. People in the two groups that followed the DASH diet most closely were less likely to develop depression than people in the group that did not follow the diet closely. The odds of becoming depressed over time was 11 percent lower among the top group of DASH adherers versus the lowest group. On the other hand, the more closely people followed a Western diet -- a diet that is high in saturated fats and red meats and low in fruits and vegetables -- the more likely they were to develop depression.
Cherian noted that the study does not prove that the DASH diet leads to a reduced risk of depression; it only shows an association.
From The Atlantic: The Diet That Might Cure Depression
.... The study has not been published yet in a peer-reviewed journal, but other researchers have found similar antidepression benefits from the DASH diet, which was developed by the U.S. National Heart, Lung, and Blood Institute..... Past research has found that following the DASH diet was associated with reduced depression in adolescent girls and with less physician-diagnosed depression among thousands of Spaniards. The results in teens suggest that diet could be a way to stave off some mental disorders entirely, since half of all mental illnesses start in the teen years.
Jacka found in 2010 that women who ate a diet high in produce, meat, fish, and whole grains had lower odds of major depression and anxiety than others. Since then, a meta-analysis of 21 studies found that “a dietary pattern characterized by high intakes of fruit, vegetables, whole grain, fish, olive oil, low-fat dairy and antioxidants and low intakes of animal foods was apparently associated with a decreased risk of depression.”