Plant Sterols and Stanols: What You Need to KnowDo They Really Help Lower Cholesterol?
-- By Becky Hand, Licensed & Registered Dietitian
Heart health is on a lot of people's minds these days, especially as more and more people are developing high blood pressure, high cholesterol and type II diabetes. You may think that you're on your way to figuring it all out, too. Eating a heart-healthy diet? Check. Engaging in regular exercise to improve your cardiovascular fitness? You bet. Working to achieve or maintain a healthy weight? Of course.
So when new products comes to market, whether a prescription medication you see on a TV commercial or the latest "functional foods" from the grocery, you probably feel confused all over again. Plant sterols and plant stanols are becoming increasingly popular as supplements and food additives. If you've seen (or used) orange juice, yogurt, and chocolates that boast cholesterol-lowering benefits, then you've probably encountered plant sterols and stanols without even knowing it. The foods that contain them boast heart healthy benefits on their packages, which may have caught your interest. So what are these sterols and stanols? Do you need them? But maybe more importantly, will they really help to lower your cholesterol?
What Are Sterols and Stanols?
Plant sterols and plant stanols are phytoesterols (small but essential components of certain plant membranes). They are found naturally (in very small amounts) in some vegetable oils, nuts, grains, legumes, fruits, and vegetables. Research has shown that plant sterols and plant stanols have the ability to help lower cholesterol. Hoping to cash in and make common food products even "healthier," food manufacturers have taken these phytoesterols from their naturally occurring sources, concentrated them, and added them to common foods that wouldn't normally contain them, such as vegetable oil spreads (margarine), mayonnaise, yogurt smoothies, orange juice, cereals, and snack bars to name a few. <pagebreak>
How Do They Work?
When you eat food that contains dietary cholesterol (which is found in animal products like meat, eggs and dairy), your intestinal tract absorbs that cholesterol and puts it into the bloodstream. Plant sterols and plant stanols are chemically similar to dietary cholesterol found in animal products. So when the sterols and stanols travel through your digestive tract, they get in the way of dietary cholesterol, preventing it from being absorbed into the bloodstream. Therefore, less total cholesterol is absorbed by your body when plant sterols and stanols are present. The cholesterol that is not absorbed leaves the body as waste. With regular use, plant sterols and plant stanols can result in a reduction in blood cholesterol levels.
Are They Safe and Effective?
Plant sterols and plant stanols have been studied for over 50 years. More than 140 published clinical studies have shown that plant sterols and plant stanols lower total cholesterol and LDL (bad) cholesterol. For example:
- Consuming 1.8 to 2.8 grams of plant sterols and plant stanols per day over a period of 4 weeks to 3 months significantly lowered total cholesterol in participants by 7%-11%.
- Consuming 2.0 to 2.5 grams of plant sterols and plant stanols per day resulted in 10%-14% reduction in LDL (bad) cholesterol without side effects.
- The National Cholesterol Education Program’s Adult Treatment Panel III also states that intakes of 2-3 grams of plant sterols and plant stanols daily will reduce LDL cholesterol by 6%-15%.
Because of the proven efficacy of sterols and stanols, the Food and Drug Administration (FDA) has approved this health claim:
“Diets low in saturated fat and cholesterol that include at least 1.3 grams of plant sterols or 3.4 grams of plant stanols, consumed in two meals with other foods, may reduce the risk of heart disease.” A food product may carry the health claim if the product itself is also low saturated fat (1g or less per serving), low in cholesterol (20mg or less per serving), and contains no more than 13 grams of total fat per serving and per 50 grams. <pagebreak>
How much do you need?
The American Heart Association's (AHA), Diet and Lifestyle Recommendations (2006) state that individuals should consume plant sterols and plant stanols from a variety of foods and beverages every day—just as they would use cholesterol-lowering medication to maintain LDL (bad) cholesterol reductions from these products. The AHA also notes that maximum effects are achieved at plant sterol and plant stanol intake of approximately 2 grams per day.
As stated above, plant sterols and stanols can occur naturally in foods or be fortified into other food products. Check out the chart below for examples of foods that contain them. Note: All amounts have been converted to grams of sterols in order to provide equivalent measures per product (0.8g sterols = 1.3 g sterol esters = 3.4 g stanol/stanol esters).
|Food Sources of Plant Sterols||Amount (grams)|
|Avocado, 1 small||0.13 g|
|Corn oil, 1 Tbsp||0.13 g|
|Sunflower seeds, 1/4 cup||0.19 g|
|Oat bar with plant sterols, 1 bar||0.40 g|
|Milk with plant sterols, 8 oz||0.40 g|
|Lifetime Low-Fat Cheese Singles, 1 slice (2/3 oz)||0.40 g|
|Carazonas Tortilla Chips, 10 chips||0.40 g|
|Nature Valley Healthy Heart Honey Nut Bar, 1 bar||0.40 g|
|Thomas’ Hearty Grains Oatmeal & Honey English Muffin, 1||0.40 g|
|CocoaVia Chocolate Covered Almonds, 13 almonds||0.70 g|
|CocoaVia Snack Bar, 1 bar||0.90 g|
|Orange juice with plant sterols, 1 cup||1.00 g|
|Vegetable oil spread with plant sterols, 1 Tbsp||1.00 g|
|Right Direction Chocolate Chip Cookies, 1 cookie||1.30 g|
|Fruit and yogurt flavored drink with plant sterols, 3.4 oz bottle||2.00 g|
Keep these points in mind if you choose to ad plant sterols and plant stanols to your diet:
- Plant sterols and plant stanols are NOT a replacement for prescribed medications. Always consult your doctor and/or a Registered Dietitian concerning any dietary changes you may make, especially if you are taking other medications.
- Consume 2 to 3 grams per day of plant sterols or plant stanols. For best results, consume sterols and stanols with a meal. Eating up to 2 grams of plant sterols or plant stanols at one sitting is fine.
- Eating more than 2 to 3 grams of plant sterols or plant stanols per day does NOT provide additional cholesterol-lowering benefits.