Sterol information by Ray Sahelian, M.D.
February 24, 2016

Sterols are steroid alcohols and are a subgroup of steroids with a hydroxyl group in the 3-position of the A-ring. Sterols form part of the cellular membrane where they influence their fluidity and function and participate as secondary messengers in developmental signaling.. The most important sterols are cholesterol, phytosterols, and some steroid hormones in animals. Phytosterols, or plant sterols, include campesterol, sitosterol and stigmasterol. You may find stanol information interesting.

Examples of phytosterols
There are a number of phytosterols including beta sitosterol, stigmasterol, campesterol, and brassicasterol. Certain herbs have a high concentration of phytosterols, for instance, saw palmetto. If you would like to purchase a Saw-Palmetto supplement..

Plant Sterols and Cholesterol
Daily consumption of plant sterols lowers LDL cholesterol in subjects with high cholesterol levels without deleterious effects on biomarkers of oxidative stress.
Snacking on cocoa-flavored bars enriched with plant sterols can reduce cholesterol levels. To examine the effect of a food enriched with plant sterols on blood levels of cholesterol and nutrients, Dr. John A. Polarus of the University of California at Davis and colleagues randomly assigned 67 people with high cholesterol to eat two snack bars containing 1.5 grams of plant sterols each every day for six weeks or two bars that did not contain a plant sterol. The enriched bar, Cocoa Via Crunch, was made by Hackett town, New Jersey-based Master foods, which helped fund the research. Study participants who ate the plant sterol enriched bars had a 5 percent reduction in total cholesterol and a 6 percent reduction in LDL cholesterol after six weeks, and also showed an increase in the amount of HDL or "good" cholesterol in relation to total cholesterol. While the plant sterol enriched bars did not affect participants' blood levels of vitamins A or E, they did reduce beta-carotene levels. Making sure to get plenty of carotenoid-rich foods such as a carrot a day while using plant sterol containing products could be enough to offset this reduction. Journal of the American Dietetic Association, November 2006.

Nutr J. 2013. Effect of a plant sterol, fish oil and B vitamin combination on cardiovascular risk factors in hypercholesterolemic children and adolescents: a pilot study. Daily intake of a combination of plant sterols, fish oil and B vitamins may modulate the lipid profile of hypercholesterolemic children and adolescents.

Reduced-calorie orange juice beverage with plant sterols lowers C-reactive protein concentrations and improves the lipid profile in human volunteers.
American Journal of Clinical Nutrition, Vol. 84, Sridevi Devaraj, Bryce C Autret and Ishwarlal Jialal. From the Laboratory for Atherosclerosis and Metabolic Research and General Clinical Research Center, University of California Davis Medical Center, Sacramento, CA. 
Dietary plant sterols effectively reduce LDL cholesterol when incorporated into fat matrices. We showed previously that supplementation with orange juice containing plant sterols (2 g/d) significantly reduced LDL cholesterol. Inflammation is pivotal in atherosclerosis. High-sensitivity C-reactive protein (hs-CRP), the prototypic marker of inflammation, is a cardiovascular disease risk marker; however, there is a paucity of data on the effect of plant sterols on CRP concentrations. Results: Sterol Bev supplementation significantly reduced total cholesterol and LDL cholesterol compared with both baseline and Placebo Bev. HDL cholesterol increased significantly with Sterol Bev. No significant changes in triacylglycerol, glucose, or liver function tests were observed with Sterol Bev. Sterol Bev supplementation resulted in no significant change in vitamin E and carotenoid concentrations. Sterol Bev supplementation resulted in a significant reduction of CRP concentrations compared with baseline and Placebo Bev. Supplementation with a reduced-calorie orange juice beverage containing plant sterols is effective in reducing CRP and LDL cholesterol and could be incorporated into the dietary portion of therapeutic lifestyle changes.

Non-cholesterol sterols are present in our body at very low concentrations as compared to cholesterol. Small changes in the structure of sterol molecules confer them highly distinct biological activities. The best-known example are steroid hormones derived from cholesterol. During the past decade, our knowledge of also other biomolecules related to or derived from cholesterol, particularly plant sterols, biosynthetic precursors of cholesterol, and oxysterols, has expanded rapidly.

Brain and CNS conditions
Prog Lipid Res. 2015. Plant sterols: Friend or foe in CNS disorders? In mammals, the central nervous system (CNS) is the most cholesterol rich organ by weight. Cholesterol metabolism is tightly regulated in the CNS and all cholesterol available is synthesized in situ. Deficits in cholesterol homeostasis at the level of synthesis, transport, or catabolism result in severe disorders featured by neurological disability. Recent studies indicate that a disturbed cholesterol metabolism is involved in CNS disorders, such as Alzheimer's disease (AD), multiple sclerosis (MS), and amyotrophic lateral sclerosis (ALS). In contrast to circulating cholesterol, dietary plant sterols, can cross the blood-brain barrier and accumulate in the membranes of CNS cells. Plant sterols are well-known for their ability to lower circulating cholesterol levels. The finding that they gain access to the CNS has fueled research focusing on the physiological roles of plant sterols in the healthy and diseased CNS. To date, both beneficial and detrimental effects of plant sterols on CNS disorders are defined.

Biochem Biophys Res Commun. January 2014. Plant sterols in food: no consensus in guidelines. Plant sterols are supplemented in foods to reduce cardiovascular risk. Randomized controlled trials show 2 g of plant sterols a day reduce serum cholesterol by about 10%. This reduction in serum cholesterol levels is achieved at the expense of increased serum plant sterol levels. Findings in patients with phytosterolemia, in experimental studies and in clinical trials have lead to speculations that plant sterols might be atherogenic. In view of emerging safety issues the role of plant sterols in cardiovascular prevention has become controversial.

I would like to ask you a question regarding Sterol Ester sl side effects. I am taking 1 capsule a day in the morning for 3 months, I start getting a pressure about 2 inches above my left ear. I thought that I am getting a stroke, and went to my Dr., he sent me for a cat scan and MRI. They found no blockage on my arteries. Are those the side effects people getting from Sterol Ester sl ? I have stopped taking them and I have no more symtoms. I know other people they had the same symtoms then I had and stopped taking them also. Is it safe to take them? I also heard today that Beta-Sitosterol, Sterol Esters and Stanol Esters area Trans Fat and people getting heart problems? All three sterols bring down cholesterol. I had good result with Sterol Esters capsuls. My total cholesterol came down from 210 to 145, LDL from 119 to 68, HDL was same 72, Triglyceride from 109 to 74, but since I stopped them my numbers went up again. Do you think it is safe to go back to using these supplements?
   Long term human trials are not published as of 2010 so it is difficult to know. One idea is to use different types of supplements and alternate their use so as to not have to rely and potentially be exposed to the side effects of one type in high dosages.