Frequency of fruit consumption and savoury snacking predict psychological health; selective mediation via cognitive failures

Abstract

While there is growing interest in the link between diet and psychological health, there is a surprising lack of studies investigating the precise associations between nutrient-rich foods (such as fruit and vegetables) versus nutrient-poor foods (such as energy-dense savoury and sweet snacks), and psychological health. Similarly, the psychological processes underpinning the relationship between dietary intake and psychological health remain unclear. Hence, the present study aimed to explore the relationship between dietary consumption and psychological health, with cognitive processes as a theoretical mediator. This cross-sectional online study included 428 healthy adults (53% female; mean age= 39.7, SD= 13.0), with participants completing a range of validated questionnaires measuring dietary habits and psychological health. Stepwise multiple regression revealed that more frequent consumption of fruit was associated with reduced symptoms of depression (β = -.109, p = 0.025) and greater positive psychological wellbeing (β = .187, p < 0.001). Conversely, more frequent savoury snacking was associated with increased anxiety (β = .127, p = 0.005). Further, mediation analyses revealed that more frequent consumption of savoury snacks was associated with increased symptoms of depression, stress, anxiety, and reduced psychological wellbeing, via an increase in cognitive failures (ps < 0.001). These results provide new insights on the independent associations between certain types of food and psychological health, and the psychological mechanisms that may mediate these. Further work is now required to establish causality and determine whether these may represent modifiable dietary targets that can directly (and indirectly) influence our psychological health.

Diet quality and anxiety: a critical overview with focus on the gut microbiome

“…This approach aligns with findings that local food purchases correlate with higher diet quality, as per the AHEI-2010 (185), advocating for diet individualization to enhance health outcomes and sustainability. Regarding findings on plant-based foods, no association with anxiety occurs when fruits and vegetables are pooled together for either males, females, or mix samples, but when accounted for separately (14, 98,[120][121][122][123][124]. The same has been found for gut microbiome when differentiating between fruits and vegetables HEI scores (33).…”

“…At the genera level, positive associations were found for Bacteroides , negative associations for Prevotella , even though both genera are part of the Bacteroidetes phylum. Similarly to refined grains, savory snacks and foods high in added sugars are prevalent in Western dietary patterns and have been observed to predict increased anxiety ( 122 , 123 , 129 ). Some authors also looked at red meat intake and consistently observed positive associations with anxiety in females ( 14 , 129 – 131 ) whereas conflicting results have been found in males ( 14 , 129 ).…”

“…Gibson-Smith et al (121) and Sadeghi et al (98), in analyses adjusted for sex, found that consuming solely vegetables and both fruits and vegetables, respectively, predict decreased anxiety. No effects were found in either male, female, or mixed samples when clustering fruits and vegetables together (120,122,123) or when distinguishing between raw and processed intake (124). An interventional study also observed that tomato-juice alleviates anxiety, although no control group was included (125).…”

Key lifestyles and health outcomes across 16 prevalent chronic diseases: A network analysis of an international observational study

“…Four additional central lifestyle changes were identified: reduced snack consumption for anxiety, less smoking for COPD, more frequent exercise for depression and fatty liver disease, and longer exercise duration for irritable bowel syndrome. Frequent savoury snacking correlates with psychological health issues through cognitive failures, impacting anxiety levels [23]. Quitting smoking, which damages lung airways and impairs function, helps prevent worsening of COPD symptoms and improves overall lung health [24].…”

Reducing excess dietary saturated fat intake to improve cognition in vascular dementia

“…Excess SFAs decrease cognitive performance. 35 Reducing dietary SFAs has been linked to a reduced risk of dementia. Vascular dementia risk was three times less with lower intakes of SFAs.…”