In a recent study published in the Nutrients Journal, researchers evaluated the association between maintaining a healthy diet and mental health among Spanish nursing students.
Multivariable regression models revealed that poor adherence to the Mediterranean diet correlates with increased depressive symptoms among these students, supporting diet as a key player in mental health.
Study: Association between Depressive Symptoms and Adherence to the Mediterranean Diet in Nursing Students. Image Credit: FoxysForestManufacture/Shutterstock.com
Mediterranean diet and mental health
Low saturated fats and high vegetable oils characterize the Mediterranean diet (MD). This diet was prevalent in Italy and Greece during the 1960s and continues to be popularized by associations, including Oldway's Preservation Trust and the Diet Foundation.
Previous research has shown that the MD can contribute to reduced cancer and diabetes risk and improved cardiovascular health.
Modern cultural transitions, including urbanization, food production globalization, and Western-type consumerism, threaten the MD, seeing an overall reduction in adherence to this 'gold standard' in the diet.
Trends such as these are frequently associated with an increased risk of non-communicable diseases, of which depression and anxiety are striking.
Mental health conditions are global medical and social concerns, prompting the World Health Organization (WHO) to define positive mental health formally – "a state of well-being, both emotional and psychological, where the individual recognizes his or her potentials, adapts to the natural pressures of life, leads productive and supportive work and meets the demands of daily life."
Despite growing awareness through media and clinical campaigns, the years between 1990 to 2013 saw depressive illness increase by 53.4% and substance abuse by 45%.
Research has identified young adults between 17 and 24 at increased risk of mental health conditions, with 9% and 55% of health science students living with some form of anxiety or depression globally.
The COVID-19 pandemic only exuberated the situation, with the Spanish National Statistics Institute (NSI) reporting 4,003 suicides in 2020, significantly higher than in pre-pandemic years. These statistics cause alarm and make finding preventive measures against the condition paramount.
Some scientists have postulated that diet could improve an individual's mood and mental health. While research into the MD's cardiovascular and anti-cancer benefits has been conducted prior, the association between the MD and mental health has never been evaluated.
About the study
In the present study, researchers aimed to investigate how adherence to the MD is associated with mental health prevalence and potential sociodemographic contributors to their observed patterns.
The study was conducted on 289 randomly selected nursing students from the University of Valencia (Spain) between October 2022 and March 2023.
The sample cohort comprised 32.1% of the 901 students enrolled at the time, with individuals under 17 years and those declining to participate excluded from the study group. Participants were intimated about the study's objectives and provided with a self-administered online survey.
The survey addressed sociodemographic (gender, age, employment status, marital status) and health (height, weight, clinical reports, and self-perceived health [SPH]) variables.
The questionnaire collected data about students' lifestyles, including smoking, psychotropic drug, alcohol, and beverage consumption. Alcohol dependency was separately evaluated using the Alcohol Use Disorders Identification Test-Concise (AUDIT-C), which accurately detects abusers and individuals at risk of developing dependencies in the future.
Finally, participants were asked to provide their academic details (courses, current grade point average [GPA]) to assess academic performance variables.
Researchers separately recorded adherence to the DM using the Mediterranean Diet Adherence Screener (MEDAS-14) and mental health status using the Goldberg Anxiety and Depression Scale (GADS).
Statistical analyses were conducted on the above data using a multiple logistic regression model with DM adherence classified as the independent variable, and mental health, body mass index (BMI), and smoking comprising the dependent variables.
Of the 289 study participants, 86.5% were women between 17 and 30 (average 20.6 years). Health data indicated that 82.4% had no chronic illnesses, and 74% were in the normal BMI range. Smokers comprised 8% of the study cohort, with only 4% (13 individuals) reporting daily psychotropic drug consumption.
However, 58.1% and 61.9% of participants reported daily alcohol and beverage consumption, respectively.
Statistical analyses revealed that only 36.5% of students showed strict adherence to the MD, with no correlation between MD adherence and gender, BMI, or chronic illness status. MD adherence increased with age, but no association between drug/alcohol consumption and adherence was noted.
Smokers, however, were found to have significantly lower levels of MD adherence compared to non-smoking members of the cohort.
GADS results indicate that 45.3% and 46.4% of participants presented anxiety and depression symptoms, respectively, significantly higher than the global mean. Women were significantly more likely to show mental health symptoms than men, with slightly higher probabilities observed in older individuals.
Adherence to the MD was significantly associated with mood – participants presenting depressive symptoms had much lower adherence scores than those who did not suffer from mental health issues. Anxiety showed an identical trend, with a lack of adherence to the MD strongly predicting anxiety in participants.
"…students who obtained higher scores on the Goldberg total scale and the depression subscale showed significantly lower scores on the MD adherence questionnaire."
In the present study, researchers found a strong correlation between adherence to the Mediterranean diet and mental health concerns among Spanish nursing students. Participants who stuck to the MD had much lower anxiety and depression scores than those who did not.
While no associations were found between gender, health, or drug/alcohol consumption, participants who smoked were significantly less likely to adhere to the MD than non-smokers.
"The protective effect of the MD against depression may be due to the combination of a sufficient intake of omega-3 fatty acids and other natural unsaturated fatty acids, together with antioxidants from olive oil and nuts, flavonoids and other phytochemicals from fruit and other plant foods, and large amounts of natural folates and other B vitamins."
This research establishes the association between diet and mental health. It makes the case for incorporating a healthy diet as a preventive measure against anxiety and depression, especially for at-risk youth.
The findings support universities including low saturated fat- and high vegetable oil-containing foods in their hostels and canteens as an added means to improve overall student health and well-being.