Phytosterols health effects

Phytosterols are safe when consumed in moderate amounts, such as those used in human studies, lu humans, phytosterol intakes of up to 25 g/d for several mouths were uot associated with adverse health effects. Phytosterol-fortilied foods should be avoided by iudividuals with phytosterolemia, an extremely rare genetic disorder characterized by imusuaUy high rates of intestinal absorption of phytosterols and an increased risk of premature atherosclerosis. ... 

A concern has been raised that phytosterol doses that are effective for cholesterol reduction may impair the absorption and lower blood concentrations of fat-soluble vitamins and antioxidants. A number of studies showed that phytosterols had no effect on plasma concentrations of vitamin D, retinol, or plasma-lipid-standardized alpha-tocopherol. Moreover, the reports of the effect of phytosterols on concentrations of blood carotenoids (lutein, lycopene, and alpha-carotene) are controversial. There seems to be general agreement that phytosterol doses >1 g/d significantly decrease LDL-C standardized beta-carotene concentrations however, it remains to be determined whether a reported 15-20% reduction in beta-carotene due to phytosterol supplementation is associated with adverse health effects. Noakes et al. found that consumption of one or more carotenoid-rich vegetable or fruit servings a day was sufficient to prevent lowering of plasma carotenoid concentrations in 46 subjects with hypercholesterolemia treated with 2.3 g of either sterol or stanol esters. 

In contrast with a Step 1 or Step n diet, a high-MUFA-diet tends to raise HDL cholesterol and lower TAG concentrations [176,177,193,194]. In agreement with this evidence, hazelnut, an excellent source of MUFA and minor components [12,117] may prove to be beneficial in this respect In addition to MUFA, other components in hazelnut oil have been reported to reduce plasma total and LDL cholesterol concentrations these include PUFA [140,141,183,195], phytosterols and phy-tostanols [127,142,146], and tocotrienol [156]. Besides favorable changes in plasma fipid profiles, a MUFA-rich diet instead of carbohydrates for SEA calories may favorably affect CVD risk [196] and has positive effects on atherosclerosis [197]. Furthermore, phytosterols and phytostanols have been shown to decrease the risk of certain types of cancer [132-134] and CVD [136,137], and enhance immune functions [139], Hazelnut oil, which is an excellent source of tocopherols [12,160], has also been shown to reduce the risk of CHD [46]. As stated above, health effects of vitamin E isofotms (a-, P-, y-, and 8-tocopherols and tocotrienols) have been well documented [49,150,198,199]. 

Chapter 2 - Hypericum patulum is might be native to the Far East around China. From of old, Hypericum patulum has been used in their treatments of many diseases. Actually, Hypericum patulum contains rich in the medicinal phytochemicals such as flavonoids, essential oils, xanthones, triterpenoids and phytosterol. Very recently, the attention of pharmacognosy has started to be paid to their functions of Hypericum patulum medicinal phytochemicals. As the results, the correlations of their functions with the phytochemicals of Hypericum patulum have been begun to be found. Base on this fact, the purpose of this Chapter is to describe the phytochemicals and their human health effects oiHypericum patulum.. 

Oils from macadamia nut and the soft parts of sea buckthorn berries are both rich sources of palmitoleic acid. A wide range of positive health effects of sea buckthorn oil are indicated by the long history of application of the berries in China, and by clinical trials and animal experiments carried out in several countries. In addition to the fatty acids, several unsaponifiable components in sea buckthorn oil (phytosterols, tocopherols, and carotenoids) probably play an inportant role in the health effects of the oil. Isolation of palmitoyl-ACP-specific A -desaturases and expression of the corresponding genes in plants and microorganisms provides promising alternative enriched sources of palmitoleic acid. 

The use of phytosterols as part of diet therapy to lower LDL-C and risk for CAD is supported by both the NCEP guidelines and the FDA s health claim about the relationship between the consumption of plant sterol and stand esters and reduced risk of coronary heart disease. This section briefly discusses the efficacy of the phytosterols as arguably the most effective dietary approach to lower plasma LDL-C in most types of subjects with the least impact on habitual diets. 

Tree nuts, tree nut oils, and tree nut byproducts (defatted meals and hulls) are known to contain several bioactive and health-promoting components. Epidemiological evidence indicates that the consumption of tree nuts may exert several cardioprotective effects, which are speculated to derive from their lipid component that includes unsaturated fatty acids, phytosterols, and tocols (4). Recent investigations... 

The common pumpkin seed has been extensively studied for its beneficial effect on prostate health. Seed extracts inhibit 5-alpha-reductase conversion of testosterone to dihydrotestosterone. The mechanism of action seems to be different from that of saw palmetto, nettle root, or pygeum. Researchers speculate that betasitosterol (a phytosterol) competes with androgens, thus decreasing esposure of the prostate to hormonal stimulation. Eating pumpkin seeds (1 to 2 ounces per day) or taking gel capsules (2 to 4 per day) has shown benefits in reducing inflammation and other prostatic symptoms. 

Health benefits of phytosterols have been a topic of intense research in recent years. The main physiological effect of consuming phytosterols (2-3 g/day for 21-30 days) is their reported lowering of low density lipoprotein (LDL) cholesterol by 10-15%. The Food and Drug Administration (FDA) allows a health claim for food containing phytosterols because of the association with reduced risk of coronary heart disease (Federal Register, 2000). 

Phytosterols and phytostanols (also called plant sterols and stanols) serve as important functional food ingredients due to their cholesterol-lowering effects. Thus, the Food and Drug Administration (FDA) has issued a rare health claim for sterol- and stanol-containing products [127]. Therefore, the presence and amount of phytosterols and phytostanols in hazelnuts is important. 

In addition to obesity and hypertriglyceridemia, hypercholesterolemia is another health concern linked to various lifestyle-related diseases. Clinical investigations have revealed that the administration of phytosterols to human subjects reduces plasma total cholesterol and LDL cholesterol levels (see also Chapter 7). Meguro et al. (2(X)1) recently investigated the relative effects on semm cholesterol and TAG levels in humans caused by phytosterols dissolved in DAG compared with phytosterols dissolved in TAG. 

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