What in the world are these plant sterol things?

I wrote an article about plant sterols and stanols that I thought you all might find interesting since they are so ubiquitous on food labels. Enjoy!

Plant Sterols and Stanols Basics

By Jennifer Martin, MS, RD

As a dietitian, it is impossible to walk past certain foods in the supermarket without noticing the abundance of extraordinary claims for heart health on the product labels. There are labels that help us “Take Control” and give us a “Smart Balance” to help lower our cholesterol. Functional foods containing plant sterols and stanols that claim to lower low-density lipoprotein (LDL) cholesterol are a booming food industry trend. With coronary heart disease (CHD) as one of the leading causes of morbidity and mortality worldwide, it is likely a trend that will continue.

The use of these plant sterols and stanols to lower cholesterol is not a new concept. The intake of plant-derived sterols was first found to decrease serum cholesterol levels in research studies conducted in the 1950s.¹ Plant sterols were briefly used therapeutically to reduce blood cholesterol levels until more efficacious pharmacological agents, such as statins, were introduced.

Just as cholesterol is an essential sterol in mammalian cell membranes, plant sterols are essential components of plant membranes. There are slight structural differences between cholesterol and plant sterols that render the plant sterols minimally absorbable by humans.² The typical human consumes plant sterols everyday in plant foods, however, the amounts are much lower than those efficacious for lowering LDL-cholesterol levels in research. An intake of approximately 2gm/day of plant sterol ester has been reported to decrease LDL-cholesterol levels anywhere from 9-20%. There appears to be little additional effect at doses higher than 2.5gm/day.³

Studies have demonstrated that consuming products containing plant-derived sterol esters is beneficial and effective in normolipidemic and dyslipidemic individuals as well as those on lipid-lowering medications.² It is postulated that sterols and stanols displace cholesterol from mixed micelles, reducing intestinal absorption of cholesterol. It should also be noted that while sterols/stanols lower LDL cholesterol, they have little or no effect on serum triglycerides or high-density lipoprotein (HDL) cholesterol.³

The food industry esterifies the sterols/stanols to improve solubility, making them easier to incorporate into products such as margarine. Esterification also helps to enhance dispersion in the intestine, in turn promoting the efficacy of the products.²

The Third Report of the National Cholesterol Education Program (NCEP), more commonly known as the Adult Treatment Panel III (ATP III), included the intake of 2gm/day plant sterols/stanols as one of the therapeutic options to enhance LDL lowering.⁴

The American Heart Association (AHA) Diet and Lifestyle Recommendations 2006 Revision also includes use of plant sterols/stanols at levels up to 2gm/day as a therapeutic option to lower LDL cholesterol levels (in addition to diet and lifestyle modification).⁵ The AHA recommendations also state that individuals need to consume the products daily, the same as using a lipid-lowering medication.

In 2000, the FDA approved the first health claim for plant sterol/stanol esters and heart disease. Products eligible to carry the claim must contain at least 0.65gm of sterol esters of at least 1.7gm stanol esters per serving. The daily dietary intake of sterol/stanol esters must be consumed in 2 servings eaten at different times of the day with other foods as part of a diet low in saturated fat and cholesterol.⁶

The amount of plant sterols/stanols in functional food products varies so be sure to read the label to determine how much of the product to take for the benefits.

Jennifer Martin, MS, RD, is a northern N.J.-based freelance nutrition writer. She has worked in the fields of clinical nutrition, cardiovascular wellness and diabetes research.

REFERENCES

1. Pollak OJ. Reduction of blood cholesterol in man. Circulation. 1953;2:702-706.

2. Lichtenstein AH, Deckelbaum RJ. Stanol/sterol ester-containing foods and blood cholesterol levels. A statement for healthcare professionals from the Nutrition Committee of the Council on Nutrition, Physical Activity, and Metabolism of the American Heart Association. Circulation. 2001;103:1177-1179.

3. Katan MB, Grundy SM, Jones P, et al. Efficacy and safety of plant stanols and sterols in the management of blood cholesterol levels. Mayo Clin Proc. 2003;78:965-978.

4. Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. Executive summary of the third report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). JAMA. 2001;285:2486-2497.

5. Lichtenstein AH, Appel LJ, Brands M, et al. Summary of American Heart Association diet and lifestyle recommendations revision 2006. Arterioscler Thromb Vasc Biol. 2006;26:2186-2191.

6. Food and Drug Administration. Food labeling: Health claims; plant sterol/stanols esters and coronary heart disease. Federal Register. 2000;65:54686-54739