Effects of Cow Milk Intake at Breakfast on the Circadian Typology and Mental Health of Japanese Infants Aged 1 - 6 Years


Tryptophan intake at breakfast has been known to be effective on promoting better mental health and morning-typed life through serotonin and melatonin synthesis. For Japanese children, milk seems to be important resource for taking tryptophan at breakfast because of limited meal time in the morning. This study tries to show the effects of milk intake at breakfast on circadian typology and mental health of Japanese infants aged 1 - 6 years. An integrated questionnaire was administrated to 1100 infants aged 1 - 6 years attending nursery schools or kindergarten in June 2012. Seven hundred and forty participants (67.3%, 360 females and 380 males, mean age: 3.5 ± 1.4) answered the questionnaire. The questionnaire included questions on sleep habits, the diurnal type scale by Torsvall and ?kerstedt (1980), questions on mental health (anger and depression), and meals contents and time. Infants who took milk at breakfast showed 21.2 (±3.4, n = 537) of the diurnal type scale scores on average which tended to be higher (more morning-typed) than 20.7 (±3.5, n = 142) (p = 0.085) shown by those who did not take milk. Infants who took carbohydrate (or carbohydrate and protein resource) plus milk at breakfast were significantly morning-typed than those who took only carbohydrate (or carbohydrate and protein resource) (p < 0.001). Infants who took milk at breakfast tended to be less frequently depressed than those who did not (p = 0.098). Taking milk at breakfast might be effective to promote serotonin synthesis in the morning which could improve mental health directly and become “inner” zeitgeber for circadian clocks in infants.

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Takeuchi, H. , Wada, K. , Kawasaki, K. , Krejci, M. , Noji, T. , Kawada, T. , Nakade, M. & Harada, T. (2014). Effects of Cow Milk Intake at Breakfast on the Circadian Typology and Mental Health of Japanese Infants Aged 1 - 6 Years. Psychology, 5, 172-176. doi: 10.4236/psych.2014.52027.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Brezinova, V., & Oswald, I. (1972). Sleep after a bedtime beverage. British Medical Journal, 2, 431-433.
[2] Campelo, L. M. L., Sa, C. G., Almeida, A. A. C., Costal, J. P., & Marques, T. H. C. (2011). Sedative, anxiolytic and antidepressant activities of Citrus limon (Burn) essential oil in mice. Pharmazie, 66, 623-627.
[3] Carvelho-Freitas, M. I. R., & Costa, M. (2002). Anxiolytic and sedative effects of extracts and essential oil from Citrus aurantium L. Biological and Pharmaceutical Bulletin, 25, 1629-1633.
[4] Cubero, J., Valero, V., Sanchez, J., Rivero, M., Parvez, H., Rodriguez, A. B., & Barriga, C. (2005). The circadian rhythm of tryptophan in breast milk affects the rhythms of 6-sulfatoxymelatonin and sleep in newborn. Neuroendocrinology Letters, 26, 657-661.
[5] Engler, A. C., Hadash, A., Shehadeh, N., & Pillar, G. (2012). Breastfeeding may improve nocturnal sleep and reduceinfantile colic: Potential role of breast milk melatonin. European Journal of Pediatrics, 171, 729-732. http://dx.doi.org/10.1007/s00431-011-1659-3
[6] Guesdon, B., Messaoudi, M., Lefranc-Millot, C., Fromentin, G., Tome, D., & Even, P. C. (2006). A tryptic hydrolysate from bovine milk aS1-casein improves sleep in rats subjected to chronic mild stress. Peptides, 27, 1476-1482.
[7] Harada, T., Hirotani, M., Maeda, M., Nomura, H., & Takeuchi, H. (2007). Correlation between breakfast tryptophan content and morningness-eveningness in Japanese infants and students aged 0 - 15 yrs. Journal of Physiological Anthropology, 26, 201-207.
[8] Hwang, S.-L., Shih, P.-H., & Yen, G.-C. (2012). Neuroprotective effects of Citrus flavonoids. Journal of Agricultural and Food Chemistry, 60, 877-885. http://dx.doi.org/10.1021/jf204452y
[9] Ishii, M., Yano, H., & Suzuki, E. (2011). Evaluating the new method of milk-supply on the interval of morning-classes in elementary school. Bulletin of Faculty of Home Economy, Otsuma Women’s University, 47, 27-37.
[10] Ishii, M., Yano, H., & Suzuki, E. (2012). Evaluating the new method of milk-supply on the after-school class in elementary school. Bulletin of Faculty of Home Economy, Otsuma Women’s University, 48, 47-56.
[11] Komori, T., Matsumoto, T., Motomura, E., & Shiroyama, T. (2006). The sleep-enhancing effect of valerian inhalation and sleep-shortening effect of lemon inhalation. Chemical Senses, 31, 731-737.
[12] Laird, D. A., & Drexel, H. (1934). Experimenting with food and sleep. I. Effects of varying types of foods in offsetting sleep disturbances caused by hunger pangs and gastric distress children and adults. Journal of American Dietetic Association, 10, 89-94.
[13] Nakade, M., Akimitsu, O., Wada, K., Krejci, M., Noji, T., Taniwaki, N., Takeuchi, H., & Harada, T. (2012). Can breakfast tryptophan and vitamin B6 intake and morning exposure to sunlight promote morning-typology in young children aged 2 to 6 years? Journal of Physiological Anthropology, 31, 11.
[14] Nakade, M., Takeuchi, H., Taniwaki, N., Noji, T., & Harada, T. (2009). An integrated effect of protein intake at breakfast and morning exposure to sunlight on the circadian typology in Japanese infants aged 2 - 6 years. Journal of Physiological Anthropology, 28, 239-245.
[15] Nakagawa, Y. (1991) Relationship between health conditions and dietary habit of pre-school children: Study on breakfast and between-meal snacks. The Japanese Journal of Nutrition and Dietetics, 49, 81-90. http://dx.doi.org/10.5264/eiyogakuzashi.49.81
[16] Portaluppi, F., Smolensky, M. H., & Touitou, Y. (2010). Effects and methods for biological rhythm research on animals andhuman beings. Chronobiology International, 27, 1911-1929.
[17] Sánchez, C. L., Cubero, J., Sánchez, J., Chanclón, B., Rivero, M., & Barriga, C. (2009). The possible role of human milk nucleotidesas sleep inducers. Nutritional Neuroscience, 12, 2-8.
[18] Torsvall, M. D., & Akerstedt, T. A. (1980). A diurnal type scale: Construction, consistency and validation in shift work. Scandinavian Journal of Work & Environmental Health, 6, 283-290.
[19] Wada, K., Yata, S., Akimitsu, O., Krejci, M., Noji, T., Nakade, M., Takeuchi, H., & Harada, T. (2013). A tryptophan-rich breakfast and exposure to light with low color temperature at night improve sleep and salivary melatonin level in Japanese students. Journal of Circadian Rhythms, 11, 4. http://dx.doi.org/10.1186/1740-3391-11-4

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