Psyllium husk lowers cholesterol in children with familial hypercholesterolemia while flax seeds cut triglycerides

Children with familial hypercholesterolemia who added psyllium husk to their existing treatment for six months saw their total cholesterol fall by 13.15 percent and their LDL cholesterol fall by 15.52 percent, according to a randomized comparative trial conducted at Cairo University Children Hospital. Children who instead received whole flax seeds did not achieve significant reductions in cholesterol, but they did lower their serum triglycerides by 7.93 percent over the same period. The study, published in the Egyptian Pediatric Association Gazette, is described by its authors as the first head-to-head comparison of these two nutraceutical supplements as adjunct therapies in pediatric familial hypercholesterolemia.

Familial hypercholesterolemia is the most common inherited cardiovascular disease, affecting roughly one in 300 individuals. It arises from functional mutations in the genes responsible for LDL receptors, leaving critically elevated levels of LDL cholesterol circulating in the blood from early childhood. Unlike typical adult hyperlipidemia, the condition is not greatly influenced by dietary changes and lifestyle modification alone, and pharmacological intervention is mandatory in most cases. Atherosclerosis can be detected in affected children as early as eight to ten years of age, which is why researchers emphasize starting therapy as early as possible.

The pharmacological options for children remain constrained. Statins are the preferred first-line agents, but the United States Food and Drug Administration has not authorized their use in children younger than six years. Ezetimibe and evolocumab are not authorized below age ten, and bile acid sequestrants, though available at earlier ages, are poorly tolerated because of gastrointestinal side effects. These gaps motivated the Egyptian team to test whether two widely studied adult nutraceuticals, flax seeds and psyllium husk, could offer meaningful additional lipid lowering in children whose lipid profiles remained elevated despite maximally tolerated medication and dietary modification.

The trial enrolled sixty patients aged one to fifteen years, all diagnosed with familial hypercholesterolemia according to American Heart Association criteria combining LDL cholesterol above 155 mg/dl with a positive family history of elevated LDL cholesterol or premature atherosclerotic cardiovascular disease. Every participant had already been on a stable, individualized lipid-lowering regimen, including dietary modification and maximally tolerated medication, for at least six months before enrollment, and follow-up records showed their lipid profiles had reached a plateau. Each child therefore acted as his or her own historical control. Participants were randomly allocated using sequentially numbered, opaque, sealed envelopes to receive either 30 grams of whole flax seeds or 7 grams of psyllium husk daily for six months, on top of their established treatment.

The cohort comprised 27 females and 33 males with a mean age of 8.92 years, and baseline lipid profiles, body mass index, and anthropometric measures were comparable between the two groups. Most participants had a positive family history of familial hypercholesterolemia, and 83.3 percent were already taking statins, primarily atorvastatin, either alone or in combination with other agents. Echocardiographic findings were normal in 63.3 percent of each group, while pathologies related to familial hypercholesterolemia, such as aortic valve stenosis or left ventricular diastolic dysfunction, were detected in roughly a quarter of participants. Researchers assessed lipid profiles, dietary intake through 24-hour recalls, and anthropometrics at monthly visits, with fasting blood tests performed twice every three months.

At 24 weeks, the psyllium group’s mean total cholesterol had fallen from 540 mg/dl at baseline to 483.61 mg/dl, a statistically significant decrease with a small effect size. Mean LDL cholesterol in that group dropped from 476.7 mg/dl to 413.61 mg/dl, also statistically significant. Psyllium did not significantly affect HDL cholesterol or triglycerides. The flax group, by contrast, showed non-significant decreases in total cholesterol and LDL cholesterol, but its mean triglycerides fell from 116.08 mg/dl at baseline to 95 mg/dl after six months, a significant reduction with a moderate effect size. Notably, when the two groups were compared directly at the end of the study, the differences in final lipid measures between them did not reach statistical significance.

The supplements also diverged in their effects on diet and growth. Psyllium significantly decreased total caloric intake by 14.6 percent and carbohydrate intake by 10 percent, and produced significant reductions in weight-for-age z-score and body mass index z-score. The authors attribute this to psyllium’s nature as a completely non-caloric, highly viscous, water-soluble fiber that expands within the gastrointestinal tract, delaying gastric emptying and activating satiety pathways. Flax seeds, on the other hand, left total caloric intake unchanged, yet the weight-for-age z-score and body mass index z-score in the flax group increased significantly, an effect the researchers link to the seed’s dense energy content as an oilseed rich in alpha-linolenic acid and lipid fractions.

The mechanistic explanations offered for the two supplements differ in instructive ways. Psyllium, a highly viscous soluble fiber, acts as a natural bile acid sequestrant, trapping bile acids in the intestinal lumen and depleting the intrahepatic cholesterol pool, which forces the liver to upregulate any residual functioning LDL receptors. Its fibers also undergo anaerobic fermentation by gut microbiota, yielding short-chain fatty acids including propionate, which inhibits HMG-CoA reductase and lowers cholesterol synthesis independently of the LDL receptor pathway. Flax seeds owe their triglyceride effect to their high alpha-linolenic acid content, an omega-3 fatty acid that downregulates lipogenic enzymes responsible for VLDL synthesis in the liver, while the soluble mucilage in the seed hull was apparently insufficient to lower LDL cholesterol.

Both supplements were generally tolerated, though with a clear asymmetry. Side effects were reported by 43.5 percent of the psyllium group, with unpalatability the most common complaint at 30.4 percent, followed by flatulence and changes in bowel habits. In the flax group, only two patients reported side effects, one case of unpalatability and one transient allergic skin reaction. Compliance was similar and acceptable in both arms, at 77.75 percent for flax and 76.13 percent for psyllium, indicating that families adhered to the regimens despite the higher rate of complaints in the psyllium group.

The authors caution that their findings carry limitations, including reliance on 24-hour dietary recall, which is subject to recall bias, and the absence of genetic typing to differentiate familial hypercholesterolemia subtypes or confirm heterozygous versus homozygous status. They also note that the clinical application of these results must remain within the controlled study measures used, and they recommend future trials to validate the hypolipidemic role of these nutraceuticals in larger pediatric genetic cohorts. Within those bounds, the trial suggests psyllium husk may serve as a clinically useful natural adjunct for lowering total and LDL cholesterol in children with familial hypercholesterolemia, while flax seeds may find their niche in pediatric hyperlipidemia with elevated triglycerides, a question the authors say warrants further investigation.

Subject of Research: Adjunct nutraceutical therapy with psyllium husk and flax seeds in pediatric familial hypercholesterolemia

Article Title: A comparative study between flax seeds and psyllium husk as a 6-month adjuvant nutraceutical in pediatric patients with familial hypercholesterolemia

Article References: Gerges, M. S. Z., Mohamed, K. A., Ibrahim, T. E. E. S., & Salama, C. G. (2026). A comparative study between flax seeds and psyllium husk as a 6-month adjuvant nutraceutical in pediatric patients with familial hypercholesterolemia. Egyptian Pediatric Association Gazette, 74(1), Article 129. https://doi.org/10.1186/s43054-026-00631-3

Image Credits: AI Generated

DOI: 10.1186/s43054-026-00631-3

Keywords: familial hypercholesterolemia, psyllium husk, flax seeds, pediatrics, LDL cholesterol, triglycerides, nutraceuticals, randomized trial, lipid profile, Cairo University, dietary fiber, cholesterol