Abstract: These resins are in particular non toxic styrene, acrylic or epoxy resins, with strong cholesterol-decreasing properties, which have an apparent density in water of 0.18 to 0.20 g of dry material/ml and a water absorption capacity of 69 to 73% by weight of the polymer weight.The process for producing anionic ion exchange resins with strong cholesterol-decreasing properties in which a mixture of monomers containing a critical percentage of cross-linking monomer, consists of polymerizing at a low rate so as to give the polymer a critically predetermined and uniformly distributed degree of cross-linkage, corresponding to an apparent density in water of 0.18 to 0.20 of dry material/ml with a water absorption capacity of 69 to 73% by weight of the polymer weight, wherein the polymerization catalyst used in an organic peroxide in a concentration of 0.2 to 3%, and the cross-linking agent used is a divinyl compound in a percentage of 1.5 to 12%, at a polymerization temperature of 50.degree. to 80.degree. C.