Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada.
IMPACT Strategic Research Centre, Deakin University, Geelong, Australia.
J Epidemiol Community Health. 2016 Feb;70(2):155-61. doi: 10.1136/jech-2015-205858. Epub 2015 Aug 26.
Several cross-sectional studies have demonstrated associations between diet quality, including fruit and vegetable consumption, and mental health. However, research examining these associations longitudinally, while accounting for related lifestyle factors (eg, smoking, physical activity) is scarce.
This study used data from the National Population Health Survey (NPHS), a large, national longitudinal survey of Canadians. The sample included 8353 participants aged 18 and older. Every 2 years from 2002/2003 to 2010/2011, participants completed self-reports of daily fruit and vegetable consumption, physical activity, smoking and symptoms of depression and psychological distress. Using generalised estimating equations, we modelled the associations between fruit and vegetable consumption at each timepoint and depression at the next timepoint, adjusting for relevant covariates.
Fruit and vegetable consumption at each cycle was inversely associated with next-cycle depression (β=-0.03, 95% CI -0.05 to -0.01, p<0.01) and psychological distress (β=-0.03, 95% CI -0.05 to -0.02, p<0.0001). However, once models were adjusted for other health-related factors, these associations were attenuated (β=-0.01, 95% CI -0.04 to 0.02, p=0.55; β=-0.00, 95% CI -0.03 to 0.02, p=0.78 for models predicting depression and distress, respectively).
These findings suggest that relations between fruit and vegetable intake, other health-related behaviours and depression are complex. Behaviours such as smoking and physical activity may have a more important impact on depression than fruit and vegetable intake. Randomised control trials of diet are necessary to disentangle the effects of multiple health behaviours on mental health.
多项横断面研究表明，饮食质量（包括水果和蔬菜的摄入量）与心理健康之间存在关联。然而，针对这些关联进行纵向研究，并考虑到相关生活方式因素（例如吸烟、身体活动）的研究却很少。
本研究使用了加拿大全国人口健康调查（NPHS）的数据，该调查是一项针对加拿大人群的大型全国性纵向调查。样本包括 8353 名年龄在 18 岁及以上的参与者。从 2002/2003 年至 2010/2011 年，每两年一次，参与者报告每日水果和蔬菜的摄入量、身体活动、吸烟情况以及抑郁和心理困扰的症状。使用广义估计方程，我们针对每个时间点的水果和蔬菜摄入量与下一个时间点的抑郁症状之间的关联进行建模，同时调整了相关协变量。
每个周期的水果和蔬菜摄入量与下一个周期的抑郁（β=-0.03，95%CI -0.05 至 -0.01，p<0.01）和心理困扰（β=-0.03，95%CI -0.05 至 -0.02，p<0.0001）呈负相关。然而，一旦模型中调整了其他与健康相关的因素，这些关联就会减弱（β=-0.01，95%CI -0.04 至 0.02，p=0.55；β=-0.00，95%CI -0.03 至 0.02，p=0.78，分别用于预测抑郁和困扰的模型）。
这些发现表明，水果和蔬菜摄入量与其他与健康相关的行为和抑郁之间的关系较为复杂。吸烟和身体活动等行为对抑郁的影响可能比水果和蔬菜摄入量更为重要。需要进行饮食方面的随机对照试验，以厘清多种健康行为对心理健康的影响。
