- Understanding Mental Health. The World Health Organization (WHO) defines good mental health as a state of well-being in which an individual realizes his or her own abilities, can cope with the normal stresses of life, can work productively, and is able to make a contribution to his or her community.
- Dietary Patterns and Mental Health. The importance of nutrition for good mental health is becoming more recognized. Some dietary patterns, such as those higher in processed foods, processed meats and sweetened beverages, may be associated with increased risk for mental health disorders through increased chronic inflammation, whereas dietary pattern focusing on "whole foods" such as fruits, vegetables, nuts, seeds, legumes, and healthy fats, may be protective.
- Sugars and Mental Health. The association of sugars intake on mental health is gaining interest in both the media and scientific literature and is yet to be fully understood.
Understanding Mental Health (with a focus on Anxiety and Depression)
The World Health Organization (WHO) defines good mental health as a state of well-being in which an individual realizes his or her own abilities, can cope with the normal stresses of life, can work productively, and is able to make a contribution to his or her community (1).
The two most common mental health disorders are depression and anxiety (2). According to the Canadian Mental Health Association (CMHA), depression is “the experience of feeling sad and “down” for a long period of time, to the point of feeling hopeless, helpless, and worthless” (3). Anxiety can be defined as “an emotion characterized by feelings of tension, worried thoughts, and physical changes like increased blood pressure” (4).
In 2017, the World Health Organization (WHO) estimated that 4.4% of the general population suffered from depressive disorders, while 3.6% suffered from anxiety disorders (5). Mental health disorders are among the top 10 causes for reduced quality of life, and one of the leading causes of disability in Canada (6).
The factors associated with mental health are complex, including genetics, biology, personality, and environment (7). Some examples that increase the risk of mental health disorders include:
- Early life experiences (e.g. abuse, trauma)
- Stressful events (e.g. divorce, loss of a loved one, financial problems)
- Having a chronic illness, such as cancer, heart disease, or diabetes
- Environmental influences on a fetus (e.g. drugs and alcohol)
- Social, economic, and educational status
Dietary Patterns and Mental Health
The role of nutrition in maintaining good mental health is becoming more recognized (8). Dietitians of Canada recognizes that there are many connections between the food we eat and mental health conditions (9).
In terms of overall eating patterns, some research has shown that eating dietary pattern characterized by high intakes of fruits, nuts, vegetables, legumes, cereals, olive oil, and fish, lower intakes of meat and dairy products, and a moderate alcohol intake, may support good mental health due to higher intakes of nutrients such as B vitamins and omega 3 fatty acids. A protective role against developing mental health disorders has been suggested for both nutrients (10). A recent systematic review of twenty observational studies and six intervention trials supported an association between this type of eating pattern and a reduced risk for depression (11).
Contrary to this, an association has been found between eating a dietary pattern characterized by higher intakes of milk, red and processed meats, sweets, and sugar- or artificially sweetened beverages (12) and an increased risk for depression in several studies (13), possibly through increased levels of inflammation markers (14). Data remain limited to specifically link carbohydrate intake, either whole or refined grains, to mental health disorders (15).
Sugars and Mental Health
The association of sugars consumption on mental health is gaining interest in both the media and scientific literature but is not fully understood. There is limited research on the relationship between sugars and the risk of developing mental health disorders; most are observational and focus primarily on sugars-sweetened beverages (SSBs). To date, no randomized controlled trials have been published that specifically assess whether there is a causal effect of sugars on mental disorders.
Sugars and Depression
- A systematic review and meta-analysis (SRMA) of observational studies (4 prospective cohorts, 5 cross-sectional studies and 1 case control) to determine the association of SSB intake on the risk of depression (16). The results of this SRMA suggested that SSB consumption might be related to an increased risk for depression. However, further investigations were unable to determine whether the relationship was due to sugars or "some other pleasurable quality of soft drinks" (17).
- Other observational studies have shown conflicting findings between sugars intake and risk for depression (18, 19, 20).
Sugars and Anxiety
- There is not enough evidence to determine if sugars are associated with anxiety. Three observational studies have found an association between sugars intake and anxiety (20-22) while another cross-sectional study did not (17). These studies also noted several limitations. For example, one study only found age-specific associations (21). In addition, caffeine content in SSBs could not be separated from the sugars and therefore may have contributed to the association found with anxiety (22).
Based on the current evidence, further research is needed to gain a better understanding of the potential impacts of consuming certain dietary components, like sugars or SSBs, on maintaining good mental health and preventing mental health disorders.
- The World Health Organization. 2018. Mental Health: Strengthening our response.
- Government of Ontario. 2020. New Plan to Build Mental Health and Addictions System Will provide Ontarians Easier Access to Higher – Quality Care
- Canadian Mental Health Association. Understanding and finding help for depression.
- American Psychological Association. 2021. Anxiety.
- World Health Organization. 2017. Depression and Other Common Mental Disorders.
- CAMH. Mental illness and Addiction : Facts & Statistics.
- Canadian Mental Health Association. Fast Facts About Mental Illness.
- Collins S, Dash S, Allender S, Jacka F, Hoare E. Diet and Mental Health During Emerging Adulthood: A Systematic Review. Emerging Adulthood. July 2020.
- Davison KM, et al for Dietitians of Canada. The Role of Nutrition in Mental Health Promotion and Prevention (1). Toronto: Dietitians of Canada, 2012.
- Sanchez-Villegas, A, et al. (2006). Mediterranean diet and depression. Public Health Nutrition, 9(8A), 1104-1109.
- Shafiei F, et al. Adherence to the Mediterranean diet and risk of depression: a systematic review and updated meta-analysis of observational studies. Nutr Rev. 2019 Apr 1;77(4):230-239.
- Daneshzad E, et al. Association between a low-carbohydrate diet and sleep status, depression, anxiety, and stress score. J Sci Food Agric. 2020 May;100(7):2946-2952.
- Ljungberg T, et al. Evidence of the Importance of Dietary Habits Regarding Depressive Symptoms and Depression. Int J Environ Res Public Health. 2020;17(5):1616. Published 2020 Mar 2.
- Drake, I., et al. A Western dietary pattern is prospectively associated with cardio-metabolic traits and incidence of the metabolic syndrome. British Journal of Nutrition, 2018;119(10), 1168-1176.
- Sadeghi O, et al. The association of whole and refined grains consumption with psychological disorders among Iranian adults. Eur J Nutr. 2019 Feb;58(1):211-225.
- Hu, D., et al. Sugar-sweetened beverages consumption and the risk of depression: A meta-analysis of observational studies. Journal of Affective Disorders, 2019;245, 348–355.
- Shi Z, et al. Soft drink consumption and mental health problems among adults in Australia. Public Health Nutr. 2010 Jul;13(7):1073-9.
- Kashino, I., et al. Prospective association of soft drink consumption with depressive symptoms. Nutrition, 2021;81, 110860.
- Mrug, S., et al. Soft Drink Consumption and Mental Health in Adolescents: A Longitudinal Examination. Journal of Adolescent Health, 2021;68(1), 155–160.
- Zhang X, et al. Daily intake of soft drinks is associated with symptoms of anxiety and depression in Chinese adolescents. Public Health Nutr. 2019 Oct;22(14):2553-2560.
- Kose J, et al. A Comparison of Sugar Intake between Individuals with High and Low Trait Anxiety: Results from the NutriNet-Santé Study. Nutrients. 2021 Apr 30;13(5):1526.
- Pengpid S, Peltzer K. High Carbonated Soft Drink Intake is Associated with Health Risk Behavior and Poor Mental Health among School-Going Adolescents in Six Southeast Asian Countries. Int J Environ Res Public Health. 2019 Dec 23;17(1):132.