Multidimensional Impact of Mediterranean Diet on IBD Patients

Abstract

Background & aims: Malnutrition with the accumulation of fat tissue and nonalcoholic fatty liver disease (NAFLD) are conditions associated with inflammatory bowel disease (IBD). Visceral fat and NAFLD-related liver dysfunction can both worsen intestinal inflammation. Because the Mediterranean diet (Md) has been shown to ameliorate both obesity and NAFLD, the aim of this study was to analyze the impact of Md on the nutritional state, liver steatosis, clinical disease activity, and quality of life (QoL) in IBD patients.

Methods: Patients with IBD, both Crohn's disease (CD) and ulcerative colitis (UC), followed Md for 6 months. Their body mass index (BMI), body tissue composition, liver steatosis and function, serum lipid profile, clinical disease activity, and inflammatory biomarkers (C-reactive protein and fecal calprotectin) were collected at baseline (T0) and compared with those obtained after 6 months (T180) to evaluate the impact of Md.

Results: One hundred forty-two IBD patients, 84 UC and 58 CD, followed Md for 6 months. At T180, diet-adherent CD and UC improved BMI (UC -0.42, P = 0.002; CD -0.48, P = 0.032) and waist circumference (UC -1.25 cm, P = 0.037; CD -1.37 cm, P = 0.041). Additionally, the number of patients affected by liver steatosis of any grade was significantly reduced in both groups (UC T0 31 of 84 [36.9%] vs T180 18 of 84 [21.4%], P = 0.0016; CD T0 27 of 58 [46.6%] vs T180 18 of 58 [31.0%], P < 0.001) after dietary intervention. Finally, after 6 months of the diet, fewer UC and CD patients with stable therapy had active disease (UC T0 14 of 59 [23.7%] vs T180 4 of 59 [6.8%], P = 0.004; CD T0 9 of 51 [17.6%] vs T180 2 of 51 [3.0%], P = 0.011) and elevated inflammatory biomarkers. Mediterranean diet improved QoL in both UC and CD, but neither serum lipid profile nor liver function were modified by the diet.

Conclusions: A significant reduction of malnutrition-related parameters and liver steatosis was observed in both CD and UC patients after short-term dietary intervention based on the adoption of Md, and this was associated with a spontaneous improvement of disease activity and inflammatory markers.

Keywords: Mediterranean diet; inflammatory bowel disease; liver steatosis; quality of life.