The Impact of Lifestyle on the Immune System: Focus on Islamic Lifestyle: A Narrative Review.

"Lifestyle" is the way or style of people living in a special time and place and includes behaviors and functions of individuals which are formed in a specific geographical, economic, political, cultural, and religious context and influenced by them. Lifestyle as an essential and efficient agent, impacts different aspects of human health, including immune functions. In the Islamic lifestyle, many recommendations have beneficial effects on human health. Islamic lifestyle influences human immunity with comprehensive recommendations and rules for different stages of life from the beginning until death. Breastfeeding is strongly emphasized in the Islamic lifestyle with an essential role in passive immunity. The quality of breastfeeding has been noticed; therefore, some spiritual words during breastfeeding have been recommended, such as the name of God, which affect the mother's and baby's immune systems via the neuro-immuno-endocrine network. Islamic lifestyle, especially in nutrition and attention to permission and forbidden foods, can prevent obesity and nutritional disorders and therefore may influence infection spread and prevention of diseases. In addition, there is a good synchronization between the hours of prayer "Salat", circadian rhythm, and immune response. In fasting according to Islamic rules (Sawm), moderate hunger and thirst may result in the enhancement of T cell function, cytokine production, and NK cell activity and diminish the negative effects of cholesterol on the immune system. Emphasis on the necessity of paying attention to maintain spiritual health and piety (Taghva) and encouraging marriage are other examples of Islamic lifestyle-related recommendations with beneficial effects on human immune functions. Hence, it is believed that Islamic teaching presents patterns for a healthy life style that could be beneficial for the immune system.