Nutr Metab (Lond), 2018, Volume 9; Issue 15: Page 36. doi: 10.1186/s12986-018-0273-z.

A randomized trial of the effects of flaxseed to manage constipation, weight, glycemia, and lipids in constipated patients with type 2 diabetes.

Soltanian, N. Janghorbani, M.

Key Findings

This single-blinded, randomized, placebo-controlled trial was designed to test the hypothesis that the 10 g flaxseed consumption per day, as compared to a placebo, would reduce constipation symptoms, body weight and improve the glycemic and lipid levels in constipated patients with type 2 diabetes (T2D). The objective of this trial was to assess the beneficial effects of adding flaxseed to the normal diet for 12 weeks of intervention among patients with T2D and chronic constipation.  The results of this study show that consumption of 10 g of flaxseed baked in cookies daily for 12 weeks improved constipation symptoms, glycemic and lipid control as well as BMI and body weight. This study also revealed significant, clinically meaningful reduction of 1.5 kg/m2 BMI and 3.8 kg body weight when the flaxseed group at baseline was compared with the flaxseed group after 12 weeks therapy. Effect of flaxseed on glycemic control which showed an improvement in both FPG and HbA1c, is clinically meaningful which is comparable to the effect of many medications that are used to treat T2D.   In constipated patients with T2D, flaxseed consumption may relieve constipation symptoms as well as decrease body weight, glycemic and lipid levels. The encouraging results obtained in this trial highlight the need for a larger sample size and longer follow-up period, probably blinded, to confirm these findings and better understand the mechanisms by which flaxseed may relieve constipation in patients with T2D.

ABSTRACT

Background: To compare the effects of baked flaxseed versus those who received a placebo on constipation symptom scores, weight, glycemic and lipid control in constipated patients with type 2 diabetes (T2D). Methods: In a single-blinded, randomized controlled trial, 53 constipated patients with T2D with body mass index (BMI) 20.5-48.9 kg/m2 received either 10 g of flaxseed pre-mixed in cookies twice per day or placebo cookies for 12 weeks. The constipation symptom scores, BMI, fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1c), and lipid profile were determined at the beginning and end of 4, 8, and 12-week period. Constipation was evaluated with a stool diary (ROME III). Results: After the 12-week intervention, constipation symptom scores (2.46), weight (- 3.8 kg), BMI (- 1.5 kg/m2), FPG (- 26.7 mg/dl), cholesterol (- 37.3 mg/dl), triglycerides (- 10.4 mg/dl), LDLC (- 21.0 mg/dl), HDLC (4.7 mg/dl), cholesterol/ HDLC ratio (- 1.4 mg/dl) significantly decreased from baseline in the flaxseed group (all P-values < 0.05). The differences of absolute change of constipation symptom scores (2.46 vs. 0.41), weight (- 3.8 vs. 0.0 kg), BMI (- 1.5 vs.-0.1 kg/m2), FPG (- 26.7 vs.-1.9 mg/dl), >HbA1c (- 0.8 vs. 1.0%), cholesterol (- 37.3 vs. -10.4 mg/dl), LDLC (- 21.0 vs. -4.3 mg/dl), and HDLC (4.7 vs. -4.4 mg/dl) between the flaxseed and placebo groups were statistically significant (all P-values < 0.05). The compliance was good and no adverse effects were observed. Conclusion: In constipated patients with T2D, flaxseed cookies used as a snack may be a useful tool for decreasing constipation symptoms, weight, glycemic and lipid levels.

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