Pet.cephmlandMotorSkillr, 1992, 75, 873-874.
@ Perceptual and Motor Skills 1992
RELATIONSHIP BETWEEN DIETARY COMPONENTS AND ASPECTS OF SLEEP ' MICHELE NEUMANN AND KEITH W. JACOBS Loyola University in N e w Orleans
Strmmary.-To test the hypothesis that major dietary constituents we related to quantity or quality of sleep, 27 adult volunteers participated in a Eive-day study. Subjects completed detailed dietary logs each day, and each morning completed the St. Mary's Hospital Sleep Questionnaire. Dietary data were converted to seven major nutritional constituents and these were averaged over the 5-day period. None of the 98 correlations between diet and sleep were significant. These findings provide no support for a link between sleep and diet in adults.
Compelling physiological reasons exist to suggest that diet should influence sleep. Food provides the amino acids from which neurotransmitters are manufactured (Fernstrom & Wurtman, 1971, 1972; Wurtman, 1982); neurotransmitters play key roles in regulation of sleep cycles (Gaillard, 1985; Nicholson & Pascoe, 1990). Few studies have directly examined the relation between diet and sleep in human subjects. Lucero and Hicks (1990) asked a group of undergraduate college students who were either short- ( ~ 6 . hr.) 5 or long-sleepers (>8.0 hr.) to maintain a diary of all food that they consumed for a 21-day period. Food intake was analyzed for major dietary constituents using a computer program. Long- and short-sleepers were not significantly different in terms of number of calories, % protein, % carbohydrates, or % fat consumed. I t was hypothesized in the present study that relationships between diet and sleep would emerge if a sufficiently large number of dietary components were examined against several objectively measured sleep parameters (e.g., duration, latency, quality). Participants in this study were 27 male and female public school teachers in St. Tammany Parish, Louisiana. All were between the ages of 23 and 53 years (M = 38.4 yr.). Subjects who had sleep disorders, were pregnant, or were taking medication had been excluded from the study. Teachers were selected because they were adults who worked fixed weekly schedules. Each subject maintained a log of all foods and the quantity of each food item consumed during the day for a five-day period from Monday through Friday. Upon arising on Tuesday through Saturday mornings each subject completed a copy of the St. Mary's Hospital Sleep Questionnaire (Ellis, Johns,
'This research was based on an undergraduate honors thesis by the first author. Requests for reprints should be addressed to K. W. Jacobs, Department of Psychology, Box 194, Loyola University, New Orleans, LA 70118.
M. NEUMANN & K. W. JACOBS
Lancaster, Raptopoulos, Angelopoulos, & Priest, 1981). This instrument was scored to provide 14 measures of sleep duration, latency, and quality. The N-Squared Nutritionist-I11 computer program (North, 1985) was used to convert daily food intake into seven major nutritional components (protein, carbohydrates, fats, tryptophan, tyrosine, caffeine, and sugar). Sleep and nutritional variables were averaged across the five days. These seven dietary components were correlated with 14 separate sleep parameters (e.g., time going to bed, latency, duration, number of awakenings, quality). None of the 98 Pearson correlation coefficients (range -.38 to .25) were statistically significantly different from zero. These findings agree with those reported by Lucero and Hicks (1990). Despite refinements in nutritional analysis and the objective measurement of a large number of sleep parameters, no consistent patterns of relationships have been identified between diet and sleep in adult volunteers. REFERENCES ELLIS,B. W., JOHNS,M. W., LANCASTER, R., RAITOPOULOS, P., ANGELOPOULOS, N., & RUEST, R. G . (1981) The St. Mary's Hospital Sleep Questionnaire: a study of reliability. Sleep, 4, 93-97. FERNSTROM, J. D., & WURTMAN, R. J. (1971) Brain serotonin content: increase following ingestion of carbohydrate diet. Science, 174, 1023-1025. FERNSTROM, J. D., & WURTMAN, R. J. (1972) Brain serotonin content: physiological regulation by plasma neutral amino acids. Science, 178, 414-416. GAULAKD, J. M. (1985) Neurochernical regulation of the states of alertness. AnnaLr of Clinical Research, 17, 175-184. LUCERO,K., & HICKS,R. A. (1990) Relacionshp between habitual sleep duration and diet. Perceptual and Motor Skills, 71, 1377-1378. NICHOLSON, A. N., & PASCOE,P. A . (1990) Dopaminergic transmission and the sleep-wakefulness continuum in man. Neuropharmacology, 29, 411-417. NORTH,L. A. (1985) The N-Squared nutritionist: III. A program for analyzing and creating diets. Silverton, OR: N-Squared Computing. WURTMAN, R. J. (1982) Nutrients that modify brain function. Scientijic American, 246(4), 50-59. Accepted August 28, 1992.
'Tabled data are available in Document NAPS-04981. Remit $7.75 for photocopy or $4.00 for fiche to National Auxiliary Publications Service, c/o Microfiche Publications, POB 3513, Grand Central Station, New York, NY 10163.