Objective
To examine associations between consumption of foods typical of Mediterranean versus Western diets with positive and negative affect. Nutrients influence mental states yet few studies have examined whether foods protective or deleterious for cardiovascular disease affect mood.
Methods
Participants were 9255 Adventist church attendees in North America who completed a validated food frequency questionnaire in 2002–6. Scores for affect were obtained from the Positive and Negative Affect Schedule questionnaire in 2006–7. Multiple linear regression models controlled for age, gender, ethnicity, BMI, education, sleep, sleep squared (to account for high or low amounts), exercise, total caloric intake, alcohol and time between the questionnaires.
Results
Intake of vegetables (β = 0.124 [95% CI 0.101, 0.147]), fruit (β = 0.066 [95% CI 0.046, 0.085]), olive oil (β = 0.070 [95% CI 0.029, 0.111]), nuts (β = 0.054 [95% CI 0.026, 0.082]), and legumes (β = 0.055 [95% CI 0.032, 0.077]) were associated with positive affect while sweets/desserts (β = − 0.066 [95% CI − 0.086, − 0.046]), soda (β = − 0.025 [95% CI − 0.037, − 0.013]) and fast food frequency (β = − 0.046 [95% CI − 0.062, − 0.030]) were inversely associated with positive affect. Intake of sweets/desserts (β = 0.058 [95% CI 0.037, 0.078]) and fast food frequency (β = 0.052 [95% CI 0.036, 0.068]) were associated with negative affect while intake of vegetables (β = − 0.076 [95% CI − 0.099, − 0.052]), fruit (β = − 0.033 [95% CI − 0.053, − 0.014]) and nuts (β = − 0.088 [95% CI − 0.116, − 0.060]) were inversely associated with negative affect. Gender interacted with red meat intake (P < .001) and fast food frequency (P < .001) such that these foods were associated with negative affect in females only.
Conclusions
Foods typical of Mediterranean diets were associated with positive affect as well as lower negative affect while Western foods were associated with low positive affect in general and negative affect in women.
One in 17 Americans experience a serious mental illness in their lifetime while currently, only about 17% of United States adults are reported to be in an optimal state of mental health [1]. Associations between diet and mental illness have been reported, particularly with depression and anxiety [2], [3], [4] and [5]. However, little is known about the associations of dietary patterns and mental well-being [6] and [7].
Affect describes both the positive and negative facets of subjective well-being and has been shown to be independent of mental illness [8]. Positive affect has been associated with health outcomes including reduced cardiovascular disease risk [6]. Many of the dietary patterns associated with protection against cardiovascular disease may also be associated with mental health. Examples include prudent and Mediterranean dietary patterns characterized by a variety of fresh fruit and vegetables, certain dairy products, olive oil, fish and whole grains as well as vegetarian diets [4], [9], [10], [11] and [12]. These dietary patterns are associated with improved mood states, improved self-reported functional health and quality of life and less depression in some studies [13], [14], [15] and [16]. Western dietary patterns characterized by intake of such foods as solid fats and refined sugars [3] and [17] and lack of omega-3 fatty acids have in contrast been associated with increased depression and negative mood states [18] and [19]. Recent research has increasingly focused on the role played by positive affect in health, not solely the detrimental effects of negative affect [6]. While the notion that foods reduce the risk of developing mental disease has been suggested [20], few studies have examined the relation between foods that may be protective against mental disease and promote positive affect.
In the current paper, we examined associations of consumption of foods typical of the Mediterranean diet and of Western diets with positive and negative affect. This was an observational analysis of a largely healthy cohort of Seventh-day Adventist church goers. This population spans a wide range of geographical locations and educational levels, has limited alcohol intake and is largely non-smoking [21], both potential confounders of associations of food and affect. Most importantly, this population follows a range of dietary patterns from vegan to non-vegetarian, as vegetarian diets have been historically encouraged by the church [22], providing ample opportunity to study diets and health outcomes.
