You are what you eat? Junk food diet linked to psychological distress, California study shows

25 Feb 2019 --- Poor or unhealthy diets may be linked to moderate or severe psychological distress, regardless of gender, age, education and income, according to researchers from Loma Linda University, California, US. Published in International Journal of Food Sciences and Nutrition, the study found that adults who followed unhealthy diets were less mentally healthy than those who followed healthy diets. The research also notes that public policy and clinical practice should aim to offer dietary improvements for those coping with mental issues, with specific attention to young adults and obese patients.

“The results are similar to previous studies conducted in other countries that have found a link between mental illness and unhealthy diet choices,” says Jim E. Banta, Ph.D., Associate Professor at Loma Linda University School of Public Health and lead author of the study.

Banta also mentions that increased sugar consumption has been linked to bipolar disorder and consumption of foods that have been fried or contain high amounts of sugar and processed grains have been associated with depression. 

“This, and other studies like it, could have big implications for treatments in behavioral medicine,” Banta notes. “Perhaps the time has come for us to take a closer look at the role of diet in mental health because it could be that healthy diet choices contribute to mental health.”

Credit: Loma Linda University, California, US.The researchers stress that poor diets may exacerbate mental illness but not cause it. The study reviewed data from over 240,000 phone surveys conducted between 2005 and 2015, as part of the California Health Interview Survey (CHIS). The CHIS database includes information about socio-demographics, health status and health behaviors and is designed to provide statewide approximations for regions within California while covering several ethnic groups.

The findings showed that 17 percent of California adults may suffer from mental illness with moderate psychological distress affecting roughly 13 percent and severe psychological distress affecting roughly 4 percent.

Additionally, the study suggests that “public policy and clinical practice should more explicitly aim to improve diet quality among those struggling with mental health,” and that “dietary interventions for people with mental illness should especially target young adults, those with less than 12 years of education and obese individuals.”

An emerging body of evidence links health diets and mental health. According to a longitudinal study from the University of Leeds, UK, the daily consumption of fruit and vegetables can improve mental wellbeing and increase the frequency and quantity of consumption may also affect mental health. Although the association between mental health and fruit and vegetable intake appears to be strong, the researchers note more research is needed to determine whether this is causal

At the same time, the importance of the gut-brain axis is also continuously being explored. A Baltimore Sheppard Pratt Health System study has flags probiotics as a potential avenue of treatment to alleviate bipolar and other psychiatric mood disorders. Published in Bipolar Disorders, the research showed that a probiotic supplement reduced inflammation, which is known to exacerbate bipolar disorder, in the gut of participants hospitalized for mania.