The effect of Ramadan fasting on endocrine system.

The Effect of Ramadan Fasting on Endocrine System Nadia Boroumand1, Seyed Isaac Hashemy2* 1. 2. Department of Clinical Biochemistry, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran Surgical Oncology Research Center, Imam Reza Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran ARTICLE INFO Article type: Review article Article History: Received: 14Dec 2015 Revised: 23Dec2015 Accepted: 25Dec 2015 Published: 30Dec 2015 Keywords: Endocrine Fasting Hormone Ramadan ABSTRACT In the religion of Islam, fasting is obligatory for healthy adults during Ramadan. Millions of Muslims around the world practice fasting in this holy month which may cause different metabolic and hormonal changes due to the restrictions in regular caloric intake. Despite various studies regarding the impact of Islamic fasting on a number of hormonal values, yet there is not any obvious consensus on its impact on human health. This review was aimed to explain some possible effects of Ramadan fasting on the endocrine system which has a great impact on physiological and cellular processes through a wide variety of hormones. In conclusion, this article recommended normal people to continue fasting during this holy month because despite the modifications that occur in the secretion pattern of some hormones, it causes no major alteration in the health of normal subjects; it is also effective for maintenance of remission in some diseases. Please cite this paper as: Boroumand N, Hashemy SI. The Effect of Ramadan Fasting on Endocrine System.J Fasting Health. 2015; 3(4):148-155. Introduction Ramadan is a religious occasion for more than a billion Muslims around the world (1). It is a time to practice self-restraint and selfreflection. Fasting is seen as a way for spiritual purification during this holy month. During the fasting Muslims totally abstain from food, drink, smoking, and sexual intercourse from breaking of dawn to setting of the sun (2, 3). The length of fasting can vary from 12 to 19 hours per day depending on the geographical position and the season in which Ramadan is placed (4). Ramadan fasting is obligatory for adult Muslims, but there are some exceptions such as suffering from an illness, being on travel, pregnancy, breastfeeding, going through menstrual bleeding, etc (5, 6). Ramadan fasting is distinct from regular voluntary fasting, since it is a month per year through which Muslims have two principal meals, a pre-dawn meal (suhoor) and a meal right after the sunset (iftar) (3, 7). Therefore, this long-lasting fasting accompany with sleep time alteration may cause different metabolic and hormonal changes from regular caloric restriction (8, 9). Because of the importance of endocrine system in health and disease, and Ramadan as a major religious duty, we aimed to review the effects of Ramadan fasting on the endocrine parameters. Effect of Ramadan Fasting on Pineal Gland Pineal gland, a small endocrine gland located in epithalamus, secrets melatonin which is responsible for controlling sleepiness and wakefulness (10, 11). Since the sleep time is altered during Ramadan, it can be expected that level of melatonin would change in Ramadan; but to our knowledge, the studies regarding assessing this issue are limited. In the study conducted by Bogdan et al, a statistically significant time-related alteration was found for melatonin concentration. During Ramadan, melatonin’s night pick is lower than before Ramadan, which may be the result of a longer exposure to artificial light in Ramadan; * Corresponding author:Isaac Hashemy, Surgical Oncology Research Centre, Imam Reza Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.Email: © 2015 mums.ac.ir All rights reserved. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Ramadan and Endocrine System Boroumand N et al. although the investigators emphasized that since the experiment was performed in winter, there was only one hour longer exposure to artificial indoor light in Ramadan rather than the control period. Also, delay in the onset of increasing concentration was observed which is in accordance with the altered sleep schedule in Ramadan (12). Effect of Ramadan Pituitary Gland Fasting on Pituitary gland, a pea-sized structure gland, involves in controlling various processes such as body metabolism, reproduction, growth and maturation, blood pressure, etc. It consists of two lobes: anterior lobe producing Folliclestimulating hormone (FSH), Luteinizing hormone (LH), Adrenocorticotropic hormone (ACTH), Growth hormone (GH), Prolactin (PRL), Beta-endorphin as well as Thyroid-stimulating hormone (TSH), and posterior lobe producing antidiuretic hormone (ADH) and Oxytocin. Studies on the effects of Islamic fasting on serum concentrations of some Pituitary gland hormones have provided valuable data that are as the follows. FSH and LH are glycoprotein hormones, secreted by gonadotropes of the anterior pituitary gland. FSH is one of the hormones essential for pubertal maturation and reproductive processes of the body. In women, FSH stimulates the growth of ovarian follicles in the ovary. It also increases estradiol production. LH is involved in development of the corpus luteum. Besides, an acute rise of LH triggers ovulation. In men, FSH is responsible for spermatogenesis and LH stimulates Leydig cells in the testes to produce testosterone (1315). In a case control study on 58 premenarche girls divided in fasting and nonfasting groups, Bahreyni et al assessed the level of FSH and LH before and after Ramadan. The result showed a significant increase in FSH and LH levels of non-fasting group after Ramadan while there was no significant rise in FSH and LH concentration of fasting group after Ramadan (9). Moreover, in another study, Zangeneh et al showed no significant difference in the levels of FSH and LH in women with Polycystic Ovary Syndrome during Ramadan fasting (16). Besides, Shahabi et al reported that Ramadan fasting results in no significant J Fasting Health. 2015; 3(4):148-155. changes in the serum concentration of FSH and LH around ovulation days (14th day of menstruation). They concluded that food restriction in Ramadan could not affect the occurrence of ovulation (17). ACTH, also known as corticotropin, is a polypeptide hormone, secreted by corticotroph cells of the anterior pituitary gland. It is often produced in response to biological stress which leads to production and release of cortisol by the cortex of the adrenal gland. Few studies have evaluated the effect of Islamic fasting on the level of ACTH as a stress-response hormone. El-Migdadi et al claimed that fasting as a stress condition for body causes remarkably in (...truncated)