Phytosterols are plant based sterols like cholesterol that give structure to the plant's cell membrane (the way cholesterol does for our cells). Phytosterols can be converted into Vitamin D and cholecalciferol, both of which have wonderful effects on our skin. You'll find the sterols in the unsaponifiable portion of the oils in fats - the part that won't turn to soap when you add a base to them.
Phytosterols aid in helping our skin's barrier mechanisms recover by penetrating into the skin, rather than occluding the skin, and our body will synthesize some of these phytosterols as it would cholesterol. And it can help cholesterol absorb better when we apply it! As our skin consists of about 25% cholesterol, adding an oil high in phytosterols can go a long way in helping damaged skin recover from the abuses we put it through every day (but don't go claiming you're healing anything!)
Phytosterols can have a huge effect on skin damaged or harmed by environmental influences, such as wind chapping, sun damage, sun burn, and so on. They reduce inflammation and itching. And, of course, they help to moisturize dry skin by reducing transepidermal water loss (TEWL). In hair care products, they can offer softening of the hair strand and reduction of electrostatic charges, so no more fly-away hair for you!
Studies done on the phytosterols and polyphenols (more about those tomorrow) in olive oil show they can help repair skin damaged by the sun.
So what does this mean to us as lotion makers? Adding oils high in phytosterols can increase the efficacy of our lotions by preventing TEWL, by helping repair damaged skin, and reduce itching and inflammation (again, remember you can't make these claims without significant testing!). How awesome is that?
Join me tomorrow for fun with flavenoids!