Phytosterols in Plant Based Foods

Beta-sitosterol is the most abundant phytosterol in the human diet, typically making up 50–80% of total phytosterol intake. It has the strongest evidence for cholesterol reduction and is the primary active compound in many phytosterol supplements. It has also been studied for potential benefits in benign prostatic hyperplasia (BPH), though the evidence for that use is mixed. Plant oils, nuts, and seeds are the richest dietary sources.

Phytosterols (plant sterols) are naturally occurring compounds in plant cell membranes that are structurally similar to cholesterol. Because they compete with cholesterol for absorption in the intestine, consuming 2g of phytosterols per day is associated with an 8–10% reduction in LDL cholesterol, as confirmed by multiple meta-analyses. They are found in plant oils, nuts, seeds, grains, legumes, fruits, and vegetables.

Phytostanols are saturated forms of phytosterols — they have a slightly different molecular structure with no double bond. Both reduce cholesterol absorption by a similar mechanism. Phytostanols are less abundant in nature and are produced commercially by hydrogenating phytosterols. Fortified food products (like cholesterol-lowering margarines and plant milks) often use plant stanol esters. The cholesterol-lowering effect is comparable between the two.

These are the three most common dietary phytosterols. Beta-sitosterol is typically the most abundant (50–80% of total phytosterols in most foods) and has the strongest evidence for cholesterol-lowering. Campesterol is usually the second most common. Stigmasterol is present in smaller amounts and is particularly high in legumes and some vegetable oils. All three compete with cholesterol for intestinal absorption.