Workers who omit breakfast show a heightened risk of depressive symptoms, according to a study published in Psychiatry Research.

Depression is a widespread metal health issue that has been linked to various negative outcomes such as reduced productivity at work, lower quality of life and higher mortality. Numerous studies have revealed a link between breakfast consumption and depressive symptoms but it has remained unclear whether this relationship is causal or incidental.

Much of the previous research has failed to account for other influencing factors like diet and health-related behaviors. Furthermore, few studies have monitored this relationship over time or been able to examine how a daily breakfast might affect a person’s likelihood of developing depressive symptoms later on.

The current study sought to investigate the relationship between breakfast consumption and depressive symptoms over time by comparing baseline survey data to results from a three-year follow-up. Factory workers in Japan (aged 19-68) completed two survey questionnaires. After excluding participants who showed a baseline depressive status or a history of severe diseases, data from 716 participants was analysed.

At both baseline and follow-up surveys, participants were asked how often they had breakfast in a week and chose between “daily”, “5–6 times/week”, “3–4 times/week”, “1–2 times/week” or “less than 1 time/week”. Depressive symptoms were measured using a Japanese version of the Center for Epidemiologic Studies Depression (CES-D) scale that assessed 6 typical symptoms of depression.

Logistic regression analysis showed a significant link between skipping breakfast and depressive symptoms, even after controlling for dietary and lifestyle factors such as smoking, alcohol drinking, sleep length, job strain and physical activity levels. Since researchers collected baseline data at the start of the study and repeatedly assessed breakfast consumption over time, important trends could be revealed.

Participants who ate breakfast less than 1 time a week showed an increased risk of depressive symptoms compared to those who ate breakfast daily. Overall, results showed that the lower the frequency of breakfast consumption, the higher the risk for depressive symptoms. This suggests that eating a regular breakfast plays a protective role against developing depression.

Breakfast consumption might protect against depressive symptoms by lowering cortisol levels in the body, given that high cortisol has been linked to depression. Another protective factor might be the role of a daily breakfast in regulating the circadian clock. The current study reveals a possible causal relationship between breakfast consumption and depressive status. This association might be further confirmed in future long-term studies.

The study, “Breakfast consumption and the risk of depressive symptoms: The Furukawa Nutrition and Health Study”, was authored by Takako Miki, Masafumi Eguchi, Keisuke Kuwahara, Takeshi Kochi, Shamima Akter, Ikuko Kashino, Huanhuan Hu, Kayo Kurotani, Isamu Kabe, Norito Kawakami, Akiko Nanri, and Tetsuya Mizoue.