Epidemiological research demonstrates a protective effect against depression in individuals with high fruit and vegetable intake.
Approximately 400 million people globally suffer from depression, making the illness one of the leading causes of disability worldwide. Nutritional deficiencies of certain vitamins and minerals can result in chemical imbalances in the body, which may influence depression development. Due to the serious consequences of depression, determining means to prevent depression is of paramount importance for the international community. Many individual studies have explored the connection between diet and depression. Research has demonstrated a positive effect of fruits and vegetables on mental health status, but until recently, there lacked a consensus from the research community on fruit and vegetable intake and risk of depression.
In 2016, Nutrition, The International Journal of Applied and Basic Nutritional Sciences published a comprehensive study on fruit and vegetable intake and risk of depression. The study is the first to compile and analyze all published research on the topic and included publications from around the world, including articles from Asia, Europe, Oceania, North and South America. Fruit and vegetable intake was assessed via food frequency questionnaires and mental health status by questionnaires, interview, self-reported physician diagnosis or use of regular antidepressant medication.
The strength of this type of research model, the meta-analysis, is the sheer amount of information included to arrive at the final result. When data from multiple studies are pooled together, greater statistical power is leveraged from the weighted average of all the included study results. Accuracy is improved when more information is collected and the final result is generalizable to a larger population.
The Results of the Study
This analysis included 10 large research studies and nearly 450,000 participants. Findings demonstrate that fruit and vegetable intake was significantly associated with a decreased risk of depression. Participants with the highest vs. lowest levels of fruit and vegetable intake decreased their risk of depression by 14% and 11%, respectively.
Researchers pooled the average decreased risk results from each of the 10 studies together to arrive at the average decreased risk of 14% for high fruit and vegetable intake and 11% for low fruit and vegetable intake. As a result, the study did not include specific parameters for what high and low intake of fruit and vegetable intake meant. Regardless, the strength of this study is that all levels of fruit and vegetable intake were protective against depression, providing significant evidence and grounds for us to recommend individuals consume fruits and vegetables daily to lower their risk of depression.
Eating fruits and vegetables reduces the risk of chronic diseases and obesity and improves mental health, as the present study demonstrates. Every five (5) years, the United States Department of Agriculture (USDA) releases updated dietary information for the general public via the Dietary Guidelines for Americans. The 2015-2020 Dietary Guidelines update recommends Americans aim to fill half their plates with fruits and vegetables during each meal and snack (See MyPlate Info). The goal of the initiative is to simplify the process of eating fruits and vegetables, eliminating the need to stress over servings. Just remember to fill half your plate with fruits and veggies every time you eat to benefit your physical and mental health.