Fasting is not merely an act of worship; it is also a remedy and a cure for many illnesses. Moreover, it allows for a renewal of the cells and of the body's activity, as well as a complete reform. When one knows the benefits of fasting, one feels its gentleness, and Allah said: "
"O you who believe! Fasting has been prescribed for you as it was prescribed for those before you, so that you may attain piety" (Qur'an 2:183).
Fasting is the best way to flush out accumulated toxins, and the Prophet ﷺ said: "Fasting is a shield," meaning a prevention. Indeed, it has been proven that fasting increases the vitality of the cells and clears the body of several chronic illnesses.
Furthermore, many physicians point out that fasting revitalizes the immune system. It increases the body's resistance against disease, and as we know, the immune system is, in a way, an army of soldiers defending the body against all the actions of bacteria and viruses. Fasting acts as a weapon helping the body defend itself, so it can be considered the undisputed master of all remedies, by Allah's permission.
Today, medicine regards fasting as a major cause of longevity. Studies have shown that fasting is a protection and confirm that dates with water are the best way to break the fast, because of the vitamins, sugars, and minerals contained in dates, which the body needs. On this subject, the Prophet ﷺ said: "When one of you wants to break his fast, let it be with a date; if he cannot find one, let him take water, for water is purity."
What the science says: fasting
What published research says about the remedies mentioned above, for context — these studies address material causes; healing belongs to Allah.
Fasting
Fasting, prescribed and then recommended by the Sunnah (Monday-Thursday, the white days), is studied today under the name intermittent fasting: a meta-analysis in the BMJ shows favorable effects on weight and cardiometabolic risk factors (BMJ, 2025), with an impact on appetite (Nutrients, 2023) and body composition (Diabetes Obes Metab, 2024). Precaution: people with diabetes on insulin, pregnant women, nursing mothers, or those in fragile health should adapt their fasting with their doctor — Islam permits, and sometimes requires, not fasting in case of illness.
