Psyllium Husk

What the evidence says

A meta-analysis of 28 randomized trials involving 1,924 participants found that a median dose of about 10.2 g per day reduced LDL cholesterol by 0.33 mmol/L, non-HDL cholesterol by 0.39 mmol/L, and apoB by 0.05 g/L. Evidence quality was moderate for LDL and non-HDL and high for apoB.^[1]

An updated constipation meta-analysis found that fiber increased stool frequency, with significant results for psyllium and larger effects at higher doses and treatment lasting at least four weeks. This supports symptom management, not a claim that every digestive complaint is fiber-responsive.^[2]

FDA permits an authorized health claim linking soluble fiber from psyllium-containing foods with reduced coronary-heart-disease risk when used as part of an appropriate diet. The claim rests on LDL lowering; randomized trials have not directly shown that psyllium prevents heart attacks or extends life.^[3][1]

Other effects are smaller and more population dependent. Meta-analyses report a modest average reduction in systolic blood pressure and better fasting glucose or HbA1c mainly in people with diabetes or dysglycemia, while a weight meta-analysis found no significant effect on body weight, BMI, or waist circumference.^[5][6][7]

Psyllium expands in liquid and must be taken with adequate fluid. MedlinePlus advises at least 240 mL with a dose and warns against use in swallowing difficulty or intestinal blockage; it can also alter absorption of some medicines.^[4]