title: Prolonged fasting in patients with chronic pain syndromes leads to late mood-enhancement not related to weight loss and fasting-induced leptin depletion.
abstract: Periods of fasting are practiced worldwide on a cultural/religious background, and related mood-enhancing effects are postulated. We aimed to assess the effect of fasting on mood and to explore the interaction with neuroendocrine activation and leptin depletion in a controlled explorative study on consecutive inpatients (BMI < 35 kg/m2) of a nutritional ward. 36 subjects (38.9 +/- 7.0 years; 29 female, BMI 26.7 +/- 4.1 kg/m2) participated in an 8-day modified fast (300 kcal/day), 19 patients (38.1 +/- 5.9 years; 18 female, 23.5 +/- 4.1 kg/m2) received a mild low calorie diet. Measurements included daily ratings of mood (VAS), weight and levels of leptin and cortisol at four time-points of the 2-week study period. Weight loss was 4.8 +/- 1.2 and 1.6 +/- 0.9 kg in fasters and controls, respectively. Fasters showed a more pronounced decrease of leptin (58% vs. 20%; P < 0.001) and a 17% increase of cortisol levels (P < 0.001). Mood ratings increased significantly in the late phase of fasting (P < 0.01) but were not related to weight-loss, leptin-depletion or cortisol increase. Our findings suggest that fasting induces specific mood-enhancement. The physiological mediator appears to be neither leptin nor cortisol, the role of other mechanisms has to be further studied.
authors.affiliation: Department of Internal Medicine V, University Duisburg-Essen, Kliniken Essen-Mitte, Am Deimelsberg 34 a, 45276 Essen, Germany. andreas.michalsen@uni-essen.de
authors.forename: Andreas
authors.initials: A
authors.lastname: Michalsen
authors.forename: Martin K
authors.initials: MK
authors.lastname: Kuhlmann
authors.forename: Rainer
authors.initials: R
authors.lastname: Lüdtke
authors.forename: Marcus
authors.initials: M
authors.lastname: Bäcker
authors.forename: Jost
authors.initials: J
authors.lastname: Langhorst
authors.forename: Gustav J
authors.initials: GJ
authors.lastname: Dobos
mesh_terms: D000328:Adult; D000339:Affect; D000704:Analysis of Variance; D015992:Body Mass Index; D002908:Chronic Disease; D004038:Diet, Reducing; D002149:Energy Intake; D005215:Fasting; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D020738:Leptin / Q000172:deficiency*; D008019:Life Style; D008297:Male; D010146:Pain / Q000503:physiopathology* / Q000523:psychology; D013577:Syndrome; D015431:Weight Loss / Q000502:physiology*
chemical_list: D020738:Leptin; D006854:Hydrocortisone