Interleukin-6, C-Reactive Protein and Biochemical Parameters during Prolonged Intermittent Fasting

BACKGROUND: It is well known that nutritional habits, sleeping patterns and meal frequency have profound effects on maintaining human health. Ramadan is a religious month for Islam, during which Muslims do not eat and drink during the daylight hours. The duration of restricted food and beverage intake is approximately 12 h/day for 1 month, which makes Ramadan a model of prolonged intermittent fasting. METHODS: In order to evaluate the effects of long-lasting modifications of food intake on inflammatory markers and biochemical parameters 40 healthy volunteers of normal weight 20 females aged between 20 and 38 years, 20 males aged between 23 and 39 years, body mass index (BMI) <25 kg/m(2) who fasted during Ramadan and another 28 healthy age- and BMI-matched volunteers (14 males, 14 females) who did not fast participated in the study. Venous blood samples were taken 1 week before Ramadan, during the last week of Ramadan and 3 weeks after Ramadan. Serum interleukin-6 (IL-6), C-reactive protein (CRP), homocysteine, vitamin B(12), folate, total cholesterol (TC), triglycerides, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) levels were measured. RESULTS: No significant changes were observed in serum total cholesterol, triglycerides and LDL levels. TC/HDL ratio (HDL risk factor) was decreased during and after Ramadan in both genders in the fasting group while there were no changes in the nonfasting group. IL-6 (p < 0.001), CRP (p < 0.001) and homocysteine (p < 0.01) levels were significantly low during Ramadan in the fasting subjects of both genders when compared to basal values (1 week before Ramadan). CONCLUSION: Our results demonstrate that prolonged intermittent fasting in a model like Ramadan has some positive effects on the inflammatory status of the body and on the risk factors for cardiovascular diseases such as homocysteine, CRP and TC/HDL ratio.