JAMA Pediatr., 2013, doi:10.1001/jamapediatrics.2013.1442

A Placebo-Controlled, Blinded, Randomized Clinical Trial of Dietary Flaxseed Supplementation for Children and Adolescents With Hypercholesterolemia

Wong, H. Chahal, N. Manlhiot, C. Niedra, E. McCrindle, B.W.

Key Findings:

In 2014, Health Canada approved a cholesterol lowering health claim for flaxseed. Several meta-analyses have reported that flaxseed can lower hyperlipidemia. The dosage of flaxseed used in the studies is from 20 to 50 g/d and showed significant reductions in LDLC levels but no change in HDLC or triglyceride levels. In this clinical study, no reduction in lipid levels was found in children with hypercholesterolemia. Reductions in ‘good’ HDLC level and an increase in triglyceride levels were found. Problems with the study included weight increases in subjects, difficulty of confirming adherence and compliance to the study protocol and small sample size. Based on the discrepancy between the findings of studies in adults which have resulted in health claims for flax, further trials in children are required.

ABSTRACT:

Importance: Nonpharmacological management of hypercholesterolemia in children is challenging with few available options. Objectives: To determine the safety and efficacy of dietary flaxseed supplementation in the management of hypercholesterolemia in children. Design: Four week placebo controlled, blinded, randomized clinical trial. Setting: Specialized dyslipidemia clinic at a tertiary pediatric care center. Participants: Thirty two participants aged 8 to 18 years with low-density lipoprotein cholesterol from 135 mg/dL (3.5 mmol/L) to < 193 mg/dL (5.0 mmol/L). Intervention: The intervention group ate 2 muffins and 1 slice of bread daily containing ground flaxseed (30 g flaxseed total). The control group ate muffins and bread substituted with whole wheat flour. Main Outcome and Measure: Attributable change in fasting lipid profile. Results: Dietary flaxseed supplementation resulted in an attributable decrease of 7.35 mg/dL (- 0.19 mmol/L) in high density lipoprotein cholesterol (95% CI, – 3.09 to – 11.60 mg/dL[0.08 to 0.30 mmol/L]; relative: – 15%, 95% CI, – 24% to – 6% ), an increase of 29.23 mg/dL (- 0.33 mmol/L) in triglycerides (95% CI, 4.43 to 53.14 mg/dL [0.05 to 0.60 mmol/L]; relative: – 26%, 95% CI, – 4% to – 48%), and an increase of 4.88 g/d in dietary polyunsaturated fat intake (95% CI, – 0.22 to – 9.53; relative: 76%, 95% CI, – 3% to 48%). Flaxseed had no attributable effects on total cholesterol (8.51 mg/dL [0.22 mmol/L]; 95% CI, 21.66 to 4.25mg/dL [0.56 to 0.11 mmol/L]; relative: 4%, 95% CI, 10% to 2%), low density lipoprotein cholesterol (6.96 mg/dL [0.18mmol/L]; 95% CI, 16.63 to 2.71 mg/dL [0.43 to 0.07 mmol/L]; relative:5%, 95% CI, 12% to 2%), body mass index z score 0.002; 95% CI, 0.147 to 0.150; relative:0%, 95% CI,12% to12%) or total caloric intake (117 kcal; 95% CI, 243 to 479; relative: 8 %, 95 % CI, 17% to 33%). An attributable change in total and low-density lipoprotein cholesterol failed to exclude a potential benefit of flaxseed supplementation based on a prespecified minimum clinically important reduction of 10%. No concerns were noted regarding safety. Conclusions and Relevance: The use of dietary flaxseed supplementation, while safe, was associated with adverse changes in the lipid profile of children with hypercholesterolemia, although a potential benefit of low density lipoprotein cholesterol lowering could not be excluded. The use of flaxseed supplementation in children with hypercholesterolemia might not be a viable option for lipid management in this population. (Authors abstract)

Link to Full Text

Full Text