The Example of How Fibre in the Diet Lowers Cholesterol in the Blood. The amount of fibre in the diet also influences the cholesterol levels and LDL cholesterol can be lowered by taking diets rich in fibres. The most significant sources of dietary fibre are unprocessed wheat bran, whole cereals such as wheat, rice, barley, rye; legumes such as potato, carrot, beet and turnips; fruits like mango and guava and green vegetables such as cabbage, lady's finger, lettuce and celery. Oat bran is especially beneficial in lowering LDL cholesterol. Expect effects of 8 to 15 mg/dl after consuming 30 g of oat bran each day for 30 days.