Check out these Clinical Research Summaries and show off your knowledge of plant sterol trivia at your next dinner party!
Want to become the cholesterol-lowering envy of all your friends? Look no further. The science behind plant sterols and their cholesterol-lowering power has been well researched and documented. We’ve compiled the most important and influential studies over the past decade for people adhering to the American Heart Association Diet, or anyone else interested in heart healthy, low cholesterol eating!
Healthier AND smarter in just one web page. Brilliant. And tasty!
Effects of phytosterol source on cholesterol lowering were evaluated in 95 healthy men and women with normal or slightly elevated cholesterol. Results showed that consumption of commercial margarine-type spreads containing Stanol esters and soybean sterol esters reduced total and LDL cholesterol by 8-13%. HDL cholesterol was unaffected, contributing to improved LDL/HDL ratio. Blood levels of some carotenoids were reduced. (Westrate JA et al. 1998Eur J Clin Nutr 52:334)
In an evaluation of effects of dose on cholesterol lowering, 100 healthy men and women with normal or slightly elevated cholesterol consumed butter, commercial margarine-type spread, margarine-type spread with 0.83, 1.61 or 3.24 g sterols (1.3, 2.6 or 5.2 g as esters) per day for 3.5 weeks. All three sterol ester-fortified margarines reduced total and LDL cholesterol by 5-10%. There were no significant differences in cholesterol lowering among the three doses; therefore, scientists concluded that the lowest effective dose was 0.83 g sterols (1.3 g sterol esters) per day. HDL cholesterol was unaffected, contributing to improved LDL/HDL ratio. Blood levels of lipid-standardized vitamin E and vitamins K and D were unaffected, but some carotenoids were reduced.
(Hendriks HFJ, et al. 1999 Eur J Clin Nutr 53:319)
Effects of fortified low-fat grains and spreads on cholesterol lowering were evaluated in a two part study.
(A) 22 men and women with elevated cholesterol levels and already on low fat, low cholesterol diets consumed 2.4 g total sterols (3.8 g sterol esters) or non-esterified stanols as part of three foods (cereal, bread, and margarine). Those foods were consumed 2 or 3 times per day for 4 weeks. Results showed that sterol esters significantly reduced total cholesterol by 8.5% compared to 3.5% by stanols. Both sterol esters and stanols significantly reduced LDL cholesterol by 13.6% and 8.3%, respectively. HDL cholesterol and triglycerides also were unaffected.
(B) 15 of the same subjects from A, already on low fat, low cholesterol diets, consumed 2 spreads for 4 weeks. Dairy spread (mixture of butter and oil blends) (control), or dairy spread with 2.4 g sterols (3.8 g sterol esters) per day.
Total and LDL cholesterol levels increased by about 6% with consumption of the dairy spread, while sterol esters added to the dairy spread reduced total and LDL cholesterol levels by 8.5% and 12.2%, respectively. HDL cholesterol levels were unaffected by treatment, triglyceride levels increased with the dairy spread.
Comment: Phytosterols were shown to blunt the cholesterol-raising effect of butter.
(Nestel P, et al. 2001 Eur J Clin Nutr 55:1084)
Effects sterols in children at risk of premature heart disease were evaluated in 38 children, ages 7 to 12 years, with familial hypercholesterolemia. Children consumed 2 Margarine-type spreads (control) or spread with 1.6 g sterols (2.6 g sterol esters) per day for 8 weeks. Results showed that esterified plant sterols reduced total cholesterol levels by 7.4% and LDL cholesterols levels by 10.2%. HDL cholesterol was unaffected, contributing to improved LDL/HDL ratio. Triglycerides were unaffected, but lipid-standardized vitamins A and E were elevated. Blood levels of some carotenoids were reduced.
Comment: Familial hypercholesterolemia is an inherited condition caused by a mutation in the LDL receptor gene. Esterified plant sterols were found to modify high cholesterol levels associated with this genetic risk factor. (Amundsen AL, et al. 2002 Am J Clin Nutr,76:338.)
STUDY 5. In an evaluation of time in days needed to obtain the full cholesterol-lowering effect of stanol esters in mild to moderately hypercholesterolemic subjects, eleven study participants consumed stanol ester margarine (2.0 g/day of stanols) as a part of their habitual diet for 14 DAYS. Effects of plant sterol esters on serum LDL cholesterol concentrations were fully obtained within 1–2 weeks of the use of plant sterol ester-enriched margarine.
(Hallikainen M et al. 2002 BMC Cardiovascular Disorders 2:14.)
A study was conducted in men and women with primary hypercholesterolemia to determine whether plant sterol-ester margarine has an additive or interactive effect on low-density lipoprotein (LDL) cholesterol reduction when ingested in combination with a statin drug. In subjects with primary hypercholesterolemia, statin and sterol-ester margarine used together produce a purely additive effect on LDL cholesterol reduction. The addition of sterol-ester margarine to statin therapy offers LDL cholesterol reduction equivalent to doubling the dose of statin. The use of dietary phytosterol esters/sterols along with statins has been shown to have an additive effect on cholesterol reduction. One study found that statins reduced LDL cholesterol by 32%, and added phytosterol esters further reduced LDL cholesterol by 7 percent, for a total cholesterol reduction of 39 percent. (Simons LA2002. Am J Cardiol 90:737)
Effect of long-term use of sterol-containing spreads was valuated in 185 healthy men and women with fasting cholesterol levels less than 310 mg/dL. Study participants consumed either margarine-type spread (control) or spread with 1.6 g sterols (2.6 g sterol esters) per day for 1 year. Sterol esters in spreads reduced total and LDL cholesterol levels by 4% and 6%, respectively, compared to the control spread. Cholesterol reduction was sustained throughout the whole year for both men and women. HDL cholesterol, triglycerides and lipoprotein (a) were unaffected. Blood levels of some carotenoids were reduced. There was no difference between groups in observed adverse events.
Comment: “This study therefore indicates that daily consumption of 1.6 g of plant sterol in the long-term, consistently lowers blood cholesterol levels and does not appear to have any adverse health effects.” (Hendriks HFJ, et al. 2003 Eur J Clin Nutr 57:681)
The impact of consuming margarine enriched with plant sterols on blood lipids, platelet function, and fibrinogen level was evaluated in 42 healthy young men. Margarine with sterols, through its antiplatelet activity and the significant reduction of LDL-C, can play a vital role in the nonpharmacologic prevention of circulatory diseases. (Kozlowska-Wojciechowska M et al. 2003 Nutrition, Metabolism: clinical and experimental 52:11)
Long-term consumption of plant stanol esters, non-nutritive bioactive constituents of plants, lowers serum cholesterol to the extent expected to reduce clinical manifestation of coronary heart disease by over 20% without detectable side effects, cholesterol lowering being especially effective in combination with cholesterol synthesis inhibitors statins.
(Miettinen TA et al. 2003. Journal for Vitamin and Nutrition Research 73(2): 127-34)
To extend the application of phytosterols to fried foods, free phytosterols were adequately heated and then cooled in fat, which caused the phytosterols to recrystallized. That process rendered the phytosterols bioavailable for blocking cholesterol absorption. In a human study, subjects (n = 7) consumed two 28-g servings of tortilla chips fried in oil with or without phytosterols that provided 0 or 1.5 g/d for 4-wk periods in a crossover design. During consumption of the phytosterol-enriched chips, significant reductions in plasma cholesterol (10%) and LDL cholesterol (15%) were achieved without affecting HDL-C. This novel means of delivering free phytosterols proved to be both functionally efficient and effective. (Hayes KC et al. 2004. J Nutition 134:1395)
An evaluation of alternative dietary strategies to achieve reduction of serum lipids was completed with 29 healthy volunteers. Including a plant sterol-enriched fat spread in a cholesterol-lowering diet produces a more favorable plasma lipid profile than the same diet made lower in total and saturated fat by replacing the spread with carbohydrate-rich foods. Isocaloric substitution of plant sterol-enriched fat spread for carbohydrate-rich foods in a low-fat, fibre-rich diet decreases plasma low-density lipoprotein cholesterol and increases high-density lipoprotein concentrations. (C. Murray Skeaff CM et al. 2005. Nutrition, Metabolism & Cardiovascular Diseases, In press.)
STUDY 12. Plant sterols are naturally occurring molecules that humanity has evolved with. Herein, we have critically evaluated recent literature pertaining to the myriad of factors affecting efficacy and safety of plant sterols in free and esterified forms. We conclude that properly solubilized 4-desmetyl plant sterols, in ester or free form, in reasonable doses (0.8–1.0 g of equivalents per day) and in various vehicles including natural sources, and as part of a healthy diet and lifestyle, are important dietary components for lowering low density lipoprotein (LDL) cholesterol and maintaining good heart health. (A. Berger et al. 2004. Lipids in Health and Disease 3:5)