Fiber intake and inflammation in type 1 diabetes

BACKGROUND Higher intake of dietary fiber is associated with lower risk of coronary heart disease, the leading cause of mortality among people with type 1 diabetes. The protective effect includes the anti-inflammatory properties of some foods. Population-based studies have shown an inverse association between some nutritional habits and high sensitive -C-reactive protein (hs-CRP). This study aimed to ascertain the association between fiber intake and hs-CPR levels in patients with type 1 diabetes. METHODS This cross-sectional study was conducted with 106 outpatients with type 1 diabetes; age 40 ± 11 years; diabetes duration of 18 ± 8.8 years. Dietary intake was evaluated by 3-day weighed-diet records. Patients were categorized in 2 groups, according to fiber intake (>20 g/day and <20 g/day). RESULTS The group with fiber intake > 20 g/day had lower hs-CRP levels [median (25(th-)75(th)) 0.7 mg/dl (0.4-2.4) vs. 1.9 mg/dl (1.0-4.4); P = 0.002], than the other group. Controlled for HbA1c and energy intake, an inverse relation was observed between hs-CRP levels and total fiber [ß = - 0.030 (SE: 0.0120), P = 0.02], soluble fiber [ß = - 0.078 (SE: 0.0421), P = 0.06] and insoluble fiber [ß = - 0.039 (SE: 0.01761), P = 0.026]. Even, after additional adjustment fibers remained associated with lower hs-CRP levels. Total fibers were stratified in 4 groups: < 10 g/day, from 10 to < 20 g/day, from 20 to 30 g/day and > 30 g/day. Compared to the group who ingested < 10 g/day of total fiber (referent group), the group who consumed > 30 g/d had significantly lower hs-CRP levels [-2.45 mg/L, P = 0.012] independent of the HbA1c values. CONCLUSIONS The present study suggests that an increased consumption of dietary fiber > 30 g/day may play a role in reducing inflammation in individuals with type 1 diabetes.