Interleukin-6, C-reactive protein and biochemical parameters during prolonged intermittent fasting

Abstract
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.