This is part of our ongoing The Best Kept Secrets to Healthy Aging spotlight. Each day, we will be posting some of the great information that’s packed into our book, The Best Kept Secrets to Healthy Aging.
Phytosterols, Cholesterol and Healthy Hearts
Phytosterols are phytonutrients that occur widely throughout the plant kingdom and are present in many edible fruits, vegetables, nuts, seeds, cereals, and legumes. The most common phytosterols, B-sitosterol, campesterol, and stigmasterol, are health-promoting relatives of cholesterol – the small differences between their chemical structures and the structure of cholesterol make all the difference in the world.
Similar in form and function to cholesterol in animals and humans, phytosterols function to regulate the fluidity of cell membranes in plants.1 Phytosterols have received a great deal of attention from researchers seeking safer means of helping people maintain healthy blood cholesterol concentrations, healthy cardiovascular systems and healthy hearts. It appears that phytosterols interfere with the intestinal recycling of the cholesterol produced by the liver, effectively reducing the availability of cholesterol to the body and may also inhibit a percentage of dietary cholesterol absorption. This is likely due to the structural similarity of these compounds with cholesterol. The most effective way of dosing plant sterols seems to be with or near a meal. While some research shows that plant sterols can be effective regardless of when they are taken, other research suggests that taking phytosterols in divided doses increases their beneficial effect.
Virtually all of the research and all of the rigorous mathematical analyses of the research that have been conducted consistently show powerful associations between phytosterol consumption (in foods or in dietary supplements) and support of healthy blood cholesterol concentrations, healthy cardiovascular systems and healthy hearts.
U.S. FDA: “Phytosterols Lower LDL-Cholesterol”
After conducting an intensive and extensive detailed review of “the totality of publicly available scientific evidence,” the US Food and Drug Administration has concluded that 1) “there is significant scientific agreement to support a relationship between consumption of plant sterol esters (especially ß-sitosterol, campesterol, and stigmasterol) and reduction in the risk of developing heart disease”; 2) “plant sterol esters reduce blood total and/or LDL (the “bad” cholesterol) levels to a significant degree”; 3) blood HDL(the “good” cholesterol) levels are not decreased by the consumption of plant sterol esters; and 4) these benefits can be obtained by individuals with either elevated blood cholesterol levels or normal healthy blood cholesterol levels.2 In addition, the blood cholesterol-lowering response occurs regardless of the composition of the rest of the diet.
New Scientific Research: “Phytosterols Lower LDL-Cholesterol”
The conclusions reached by the US Food and Drug Administration have been echoed in the new research findings that have been published since the government’s decisions. For example, a study published in the Journal of Nutrition showed that regardless of the nature of the diet, the cardiovascular health of men and women with blood LDL cholesterol concentrations within the “normal” range (blood LDL cholesterol concentration less than 100 mg/dL) received additional support from the addition of phytosterols to their daily diets.3 Similar benefits were experienced in another study of men and women with initially elevated blood cholesterol concentrations.4 Studies consistently have shown that phytosterols taken in the amount of 2 to 3 grams per day can reduce LDL (low density lipoprotein) cholesterol levels by about 10%.5 In addition to their beneficial effects on blood lipid levels, phytosterols also have the ability to normalize the inflammatory response of the immune system.
A comprehensive meta-analysis published earlier this year (2009) analyzed the results of 84 clinical trials using phytosterols.6 The authors concluded that their rigorous analysis confirmed the ability of phytosterols to significantly lower LDL cholesterol levels. The ability of phytosterols to reduce LDL concentrations was found to be dose-dependent. Again, they concluded that approximately 2 grams of phytosterols taken on a daily basis seemed to reduce LDL cholesterol by nearly 10%.
Phytosterols can be added to the diet as peanut oil, extra virgin olive oil, sesame oil, soybean oil, raw or roasted peanuts, hazelnuts, macadamia nuts, flax seed, cashews, almonds, pecans, pistachios, sunflower seeds, walnuts or as a high-quality dietary supplement.
FDA Qualified Health Claim:
Dietary supplements containing at least 400 mg of plant sterols, taken twice daily with meals for a daily total of at least 800 mg, as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease.
Next Best Kept Secrets to Healthy Aging topic:
1. Brufau G, Canela MA, Rafecas M. Phytosterols: physiologic and metabolic aspects related to cholesterol-lowering properties. Nutr Res. 2008 Apr;28(4):217-25.
2. Food and Drug Administration. Food Labeling: Health Claims; Plant Sterol/Stanol Esters and Coronary Heart Disease; Interim Final Rule. Fed Reg 2000;65:54685-54739.
3. Quilez J, Rafecas M, Brufau G, Garcia-Lorda P, Megias I, Bullo M, Ruiz JA, Salas-Salvado J. Bakery products enriched with phytosterol esters, a-tocopherol and ß-carotene decrease plasma LDL-cholesterol and maintain plasma .-carotene concentrations in normocholesterolemic men and women. J Nutr 2003;133:3103-3109.
4. Vanstone CA, Raeini-Sarjaz M, Parsons WE, Jones PJ. Unesterified plant sterols and stanols lower LDL-cholesterol concentrations equivalently in hypercholesterolemic persons. Am J Clin Nutr
5. Brufau G, Canela MA, Rafecas M. Phytosterols: physiologic and metabolic aspects related to cholesterol-lowering properties. Nutr Res. 2008 Apr;28(4):217-25.
6. Demonty I, Ras RT, van der Knaap HC, Duchateau GS, Meijer L, Zock PL, Geleijnse JM, Trautwein EA.Continuous dose-response relationship of the LDL-cholesterol-lowering effect of phytosterol intake. J Nutr. 2009 Feb;139(2):271-84.