Phytosterol Esters

Figure 1. The chemical structure of Campesterol, a type of Phytosterol.

Phytosterols are phytosteroids, similar to cholesterol in the human body, that form the structural components of plant cell membranes. Phytosterols include plant sterols and stanols. Free Phytosterols extracted from plant oils are insoluble in water, relatively insoluble in oil, but soluble in alcohols.

Phytosterol Esters are obtained from the esterification of the hydroxyl group at carbon 3 with fatty/organic acids or carbohydrates. Sterol Esters can be found in trace amounts in every cell type but are highly enriched in foam cells and are common components of human skin oil. 

Phytosterol Esters can be found in many plant foods, including:

• Nuts: pistachios, macadamia nuts, almonds, cashews, peanuts, hazelnuts
• Seeds: pumpkin seeds, sunflower seeds, watermelon seeds
• Fruits: pineapples, oranges, berries, bananas, apples, apricots
• Vegetables: artichokes, broccoli, green beans, cabbage, asparagus, sweet potatoes, celery, cauliflower
• Legumes: chickpeas, lentils, mung beans, adzuki beans, soybeans
• Oils: olive oil, argan oil, sunflower oil, canola oil

Phytosterol Esters have been shown to reduce the level of low-density lipoprotein (LDL) cholesterol in blood when consumed. As such, Phytosterol Esters are commonly promoted as a dietary supplement to help with cholesterol levels in the human body. Phytosterol Esters used for dietary supplements are made from Phytosterols and Fatty Acids derived from plants. Campesterol, beta-sitosterol, and stigmasterol are three of the most common plant-derived Phytosterols used in dietary supplements.