Ramadan fasting is a unique form of intermittent fasting in which healthy adult Muslims abstain from eating and drinking daily from dawn to sunset for an entire lunar month. The daily fasting period ranges from about 12 to 18 hours depending on the season and geographical region. During this period, the body enters an important metabolic transition. After about 8-12 hours of fasting, the body begins to burn fat (producing ketones) as an alternative energy source instead of stored glucose, and the resulting biological changes such as increased lipolysis, altered insulin secretion patterns, and elevated levels of free fatty acids in the blood are considered an alternative source of energy.

Ramadan fasting has piqued the interest of researchers to know its health effects on the body, due to the resulting biological changes such as increased lipolysis, altered insulin secretion patterns, and elevated levels of free fatty acids in the blood (Norouzy et al., 2013).(Trepanowski & Bloomer, 2010). For example, a systematic review published in 2020 concluded that religious fasting (including Ramadan fasting) positively affects body weight, lipid and blood sugar levels, produces antioxidant effects, and improves kidney and immune system function (Fernando et al., 2020).

In this paper, we will review the physical, metabolic, and biological benefits of Ramadan fasting as reported in academic studies, focusing on its impact on energy metabolism, blood sugar and cholesterol levels, blood pressure, inflammatory markers, organ function, and other biomarkers.

First: Effects on blood sugar and energy metabolism

During fasting hours, the body does not receive glucose from food, forcing it to consume glycogen stores in the liver and then switch to burning fat for energy (ketosis). These metabolic changes have beneficial effects on blood sugar regulation and insulin sensitivity of cells (Patterson & Sears, 2017).Several studies have shown that Ramadan fasting generally does not lead to serious disturbances in blood sugar levels in healthy individuals; on the contrary, it may improve glycemic control by increasing insulin sensitivity and reducing insulin resistance in the body (Norouzy et al., 2013Trepanowski & Bloomer, 2010). In a follow-up study of fasting blood glucose averages, it was found that by the end of Ramadan there was a stabilization or slight decrease in fasting glucose compared to before the month, indicating the body's adaptation to maintain glucose homeostasis during the long hours of fasting (Azizi, 2010).

In the same vein, scientific reviews have found that fasting also alleviates a number of metabolic factors that affect diabetes. In addition to lowering blood sugar, fasting reduces chronic inflammation, improves blood lipid profiles, and stimulates excess weight loss, all of which are beneficial for the control and prevention of type 2 diabetes (Fernando et al., 2020These findings mean that Ramadan fasting may have a protective role against the development of insulin resistance and metabolic syndrome, especially in people at risk of diabetes, provided they adhere to a balanced diet and do not overindulge in sugars during iftar periods (Azizi, 2010).

Second: Cardiovascular health: cholesterol and blood pressure

Ramadan fasting has a clear positive impact on cardiovascular health parameters, especially in terms of improving the Lipid Profile and blood pressure (Kul et al., 2014; Fernando et al., 2020)). Studies indicate a moderate improvement in blood lipid levels after Ramadan fasting, which can contribute to the reduction of risk factors for heart disease such as atherosclerosis (Trepanowski & Bloomer, 2010).A recent systematic review (2025) that included 10 studies and 432 participants from several countries found that Ramadan fasting was associated with significant improvements in blood cholesterol levels; HDL cholesterol increased significantly and both total cholesterol and LDL cholesterol decreased significantly after Ramadan (Fernando et al., 2020).There was no statistically significant change in triglyceride (TG) levels in the overall mean, which was explained by different dietary patterns among individuals during the iftar period (Kul et al., 2014).

Similarly, clinical studies have recorded a decrease in the concentration of LDL in the blood by the end of Ramadan; for example, in one study, total cholesterol levels decreased from an average of ~193 mg/dl before to ~178 mg/dl after fasting, LDL levels decreased from ~115 to ~103 mg/dl, and triglycerides decreased by a significant amount (Norouzy et al., 2013)Although HDL cholesterol may remain largely unchanged in some individual cases, the LDL/HDL ratio (a heart risk indicator) usually improves during Ramadan in favor of a higher ratio of good to bad cholesterol (Kul et al., 2014).).These changes in blood lipids - i.e. higher HDL, lower LDL and total cholesterol while stabilizing triglycerides - all contribute to reducing the risk of atherosclerosis and coronary heart disease (Fernando et al., 2020).

In addition to modifying blood lipids, Ramadan fasting has also been observed to help lower arterial blood pressure levels in both healthy people and hypertensive patients (Habbal et al., 1998; Fernando et al., 2020). Analytical data from dozens of studies showed that after Ramadan, average systolic blood pressure (top number) decreased by about 3 to 4 mmHg, and average diastolic blood pressure (bottom number) decreased by about 2 mmHg compared to before Ramadan (Fernando et al., 2020).One field study conducted in London with 85 participants showed even greater reductions (about 7.3 mmHg in systolic and 3.4 mmHg in diastolic) after a month of fasting, but these clearer results were in a small sample and may vary depending on community conditions and eating habits (Kul et al., 2014).

More broadly, a meta-analysis of 33 studies from different countries confirmed a significant reduction in blood pressure after Ramadan in the majority of those who fasted, and this effect was found to be independent of factors such as weight loss or changes in body water intake (Fernando et al., 2020). That is, fasting itself - perhaps via autonomic nervous system regulatory mechanisms or improved vascular elasticity - contributed to lower blood pressure independent of the effect of weight loss (Mattson et al., 2017).). It is also noteworthy that lower blood pressure during Ramadan was seen not only in normotensive individuals, but also in hypertensive patients who were stable and receiving treatment, suggesting a possible therapeutic effect of fasting in these patients (Habbal et al., 1998).Of course, hypertensive patients should consult their doctors before fasting to ensure the suitability of their condition, but general indications suggest that Ramadan fasting is safe and may be beneficial for hypertensive patients by temporarily improving their blood pressure readings during the month (Fernando et al., 2020). In conclusion, it can be said that Ramadan fasting improves heart health parameters by slightly lowering blood pressure and improving cholesterol levels, reducing the cardiovascular burden and enhancing overall cardiovascular performance.

Third: Other biological and cellular benefits of fasting

In addition to the aforementioned metabolic and functional benefits, research has revealed biological benefits at the cellular level caused by Ramadan fasting, most notably the stimulation of cellular repair processes and the regulation of genes and beneficial bacteria (Mattson et al., 2017Longo & Panda, 2016). Prolonged daily abstinence during Ramadan is thought to induce self-cleansing mechanisms in the body; some references have suggested that Ramadan fasting can stimulate autophagy, a process in which the body eliminates and recycles damaged cells and aging cellular components, helping to fight aging and degenerative diseases in the long run (Levine & Kroemer, 2019; Longo & Mattson, 2014).

Although autophagy usually peaks in long, continuous fasting for days, the daily Islamic fasting pattern may activate this process every day for a certain period after immediate energy stores are depleted, contributing to tissue maintenance and minimizing the accumulation of protein waste products in cells (Mattson et al., 2017).On the other hand, a recent review study showed that the level of oxidative stress in the body decreases during Ramadan as the production of harmful free radicals decreases and the body's antioxidant capacity increases, which protects cells from oxidative damage.For example, the malondialdehyde (MDA) index - an oxidative product used as an indicator of free radical damage - was found to be lower in the blood of fasting individuals at the end of Ramadan compared to before fasting, along with an increase in antioxidant markers, although some of these changes may be subtle and influenced by dietary factors during iftar (Faris et al., 2012).). However, the overall trend suggests that the balance between oxidants and antioxidants is improved during fasting in favor of protecting cells from free radicals. This in turn may reduce the risk of chronic diseases associated with oxidative stress such as heart disease, cancer, and neuropathies (Longo & Panda, 2016).

Furthermore, beneficial changes in gut microbiome composition have been observed during the month of fasting (Su et al., 2021). Ramadan fasting, by altering the pattern and timing of meals, affects the beneficial gut bacteria and positively stimulates their diversity. Some research has shown that fasting promotes the growth of beneficial gut microbes that play a role in improving digestion and strengthening gut immunity (Su et al., 2021; Zeb et al., 2020).A shift in eating times can reset the circadian rhythm of digestive hormones and create a more harmonious environment for the microbiome (Longo & Panda, 2016). One scientific review reported that Ramadan fasting improves metabolism-related gene expression, meaning it may activate or inhibit certain genes in a way that supports body health, including genes related to lipid, insulin and inflammation regulation (Almeneessier et al., 2018).For example, a study in people with metabolic syndrome found modifications in the expression of genes important for lipid pathways and atherosclerosis after Ramadan, suggesting an effect of fasting on the level of gene expression associated with cardiometabolic diseases (Almeneessier et al., 2018). In another context, there is evidence that fasting may increase the secretion of human growth hormone (GH) during periods of hunger, which is involved in maintaining muscle mass and stimulating fat burning (Ho et al., 1988; Hartman et al., 1992).

These profound biological effects of Ramadan fasting-from activating self-repair mechanisms, to improving antioxidant balance, reducing inflammation, and regulating gut bacteria and gene expression-support the idea that fasting is not only a spiritually beneficial religious ritual, but also a holistic health regulator that may extend beyond the fasting period (Mattson et al., 2017Of course, many of these aspects are still under intense scientific research to understand their details and mechanisms, but they highlight promising prospects for using intermittent fasting as a way to improve overall health and combat the effects of aging and disease (Levine & Kroemer, 2019).

Conclusion

It is no secret that Ramadan fasting has a great spiritual and psychological significance for Muslims, but it is also clear, according to recent medical research, that it has multidimensional physical health benefits (Trepanowski & Bloomer, 2010; Fernando et al., 2020).In this paper, we have reviewed a number of scientifically documented benefits of Ramadan fasting, including improved weight control by losing excess fat and controlling appetite, improved sugar metabolism by increasing insulin sensitivity and stabilizing blood glucose levels, and restoring blood lipid balance by raising HDL cholesterol levels and lowering LDL cholesterol, which reduces the risk of atherosclerosis (Fernando et al., 2020Mattson et al., 2017). We have also seen that fasting moderately lowers blood pressure, which supports cardiovascular health, while reducing chronic inflammation by suppressing inflammatory mediators and increasing the level of anti-inflammatory factors (Faris et al., 2012).). In addition, it can boost immune function, activate cellular repair and purification via autophagy, improve oxidative stress, and combat harmful free radicals (Levine & Kroemer, 2019; Mattson et al., 2017).

Together, these benefits make Ramadan fasting an experience rich in positive effects on overall body health, especially when combined with healthy dietary behavior during iftar and suhoor, avoiding excessive sugars and harmful fats, drinking enough water, and eating a balanced diet (Azizi, 2010).It is important to note that these health benefits are conditional on moderation; overeating at iftar or staying up too late may negate some of the health benefits of fasting. Also, individuals' response to fasting varies according to their baseline health status. Most studies are conducted on healthy volunteers, while those with chronic diseases (such as diabetes, advanced heart disease or kidney disease) should consult their doctors before starting to fast (Hassanein et al., 2017).However, the overall picture based on recent research suggests that Ramadan fasting is safe and even beneficial for most healthy people, and may "provide health improvements including weight loss, reduced markers of inflammation and oxidative stress, lower blood pressure, and improved blood sugar levels" when adhered to in accordance with Sharia and health regulations (Fernando et al., 2020).Thus, Ramadan fasting can be considered an effective model of intermittent fasting that carries within it potential preventive and therapeutic benefits for the human body, which is consistent with the divine legislative wisdom in imposing this worship. In light of the increasing global interest in intermittent fasting methods to improve health, Ramadan fasting stands out as one of the most scientifically and practically studied models, which opens the door for more future research to understand its health secrets and invest them in the fields of medicine and healthy lifestyle.