Background: Few studies have been done on the association of dietary intakes with sleep disorders among shift workers, in particular those exposed to air pollution.
Objective: We aimed to investigate the association of major dietary patterns with risk of sleep disorders in shift workers of a cement factory.
Methods: This cross-sectional study was carried out on 257 male shift workers in a cement factory in Iran. Usual dietary intake of participants was assessed using a validated self-administrated 147-item dish-based food frequency questionnaire. To examine sleep disturbances of participants, we used the Epworth Sleepiness Scale.
Results: Three major dietary patterns including Classic Iranian, Modern Iranian, and High Protein Low Fruit and vegetables were identified. The Classic Iranian pattern was mainly consisted of high-protein animal foods, fruit, and vegetables, while the Modern Iranian pattern had high amounts of refined grains, solid oils, and caffeine drinks. No significant association was found between adherence to the Classic Iranian pattern and risk of sleep disorders (OR: 2.33; 95% CI: 0.69, 7.81) and also for the Modern Iranian dietary pattern (OR: 0.62; 95% CI: 0.20, 1.93). However, we found a significant direct association between the High Protein Low Fruit and vegetables dietary pattern and risk of sleep disorders (OR: 3.92; 95% CI: 1.03, 14.86).
Conclusions: This study showed a significant direct association between a dietary pattern high in animal proteins and solid oils and low in fruit and vegetables with risk of sleep disorders among shift workers in the cement factory. However, no such association was found for the two other dietary patterns.
Keywords: Food intake; circadian rhythm; diet; shift work schedule; sleep wake disorders.