Mental health and diet quality are closely linked. The food choices you made as a teenager affect the development of conduct and emotional problems that continue into adulthood. Lifestyle diseases such as heart disease, diabetes and obesity are attributed to changes in diet and exercise habits. Recently there is increasing evidence that diet and exercise also have a major influence on mental health. Dieting peaks after the festival season. This post will help you avoid the 'isms' and fads and point you in the direction indicated by current research.
A good quality diet predicts better mental health
Evaluating the quality of the complete diet provides a better and more consistent picture of nutrition status than focusing on individual nutrients like magnesium or food groups like various fatty acids (omega, polyunsaturated). A traditional diet of vegetables, fruit, meat, fish, and whole grains is associated with lower risk for depression and for anxiety disorders as compared to a "western" diet of processed or fried foods, refined grains, sugary products, and beer (Jacka 2010).
Switching to a high quality diet improves mental health
Switching to a healthy diet improves mental health. Unhealthy diets are associated with lower scores on mental health tests. The best part is that improvements in diet quality are mirrored by improvements in mental health (Jacka 2011). Also the reverse, when diet quality deteriorates psychological functioning is adversely affected.
The quality of diet is assessed using food frequency questionnaires. Points are allotted for each type and frequency of food consumed. For example one point is allotted for each of at least two fruit servings per day, at least four vegetable servings per day; using reduced fat or skimmed milk, using soy milk, consuming at least 500mL of milk per day; using high fibre, wholemeal, rye or multigrain breads; having at least four slices of bread per day; using polyunsaturated or monounsaturated spreads or no fat spread; having one or two eggs per week, using cottage cheese, using low fat cheese. Out of a maximum possible score of 74, the average is about 33.0 (+9.0).You can get some idea of your
diet quality score from this chart (Collins 2008).
Preventive psychiatry
Improving diet quality improves mental health outcomes. Especially for adolescents this is an important preventive intervention. Three quarters of all long term psychiatric illness manifest during adolescence and early adulthood (Kessler 2005) . These illness are among the most disabling. They occur with a high enough frequency to contribute a major portion of life years lost due to disability. Mental health illnesses cause long-term problems at work and at home. They usually persist over the lifetime and require medication and support at various stages. Adopting a high quality diet is an important primary preventive intervention for improved mental health - easy to implement and proven to be effective.
References
- Collins CE, Young AF, Hodge A (2008). Diet quality is associated with higher nutrient intake and self-rated health in mid-aged women. J Am Coll Nutr 27: 146–157.
- Jacka FN, Pasco JA, Mykletun A, Williams LJ, Hodge AM, O'Reilly SL, Nicholson GC, Kotowicz MA, Berk M. Association of Western and traditional diets with depression and anxiety in women. Am J Psychiatry. 2010 Mar;167(3):305-11. Epub 2010 Jan 4.
- Jacka FN, Kremer PJ, Berk M, de Silva-Sanigorski AM, Moodie M, Leslie ER, Pasco JA, Swinburn BA.A prospective study of diet quality and mental health in adolescents. PLoS One. 2011;6(9):e24805. Epub 2011 Sep 21.
- Kessler RC, Berglund P, Demler O, Jin R, Merikangas KR, et al. (2005) Lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the National Comorbidity Survey Replication. Arch Gen Psychiatry 62: 593–602.
