Egg exists as a major dietary source of cholesterol in Western diets. In North America, laying hen diets are usually devoid of cholesterol when diets are formulated to exclude animal-based products. Hence, laying hens meet their physiological cholesterol requirement through de novo synthesis. Plant sterols exert a cholesterol-lowering effect in humans by interfering with intestinal sterol absorption. However, it is unknown whether plant sterol supplementation could be effective in reducing intestinal reabsorption of biliary cholesterol in laying hens, thus modulating whole body cholesterol in favor of lower plasma and yolk cholesterol content. The current study was designed to investigate the effect of diets enriched with 0, 0.5, 1, and 2% plant sterols on cholesterol absorption, synthesis, as well as plasma, liver, and egg yolk cholesterol concentrations in laying hens. After 8 wk of plant sterol intervention (first 2 wk were acclimatization), feed intake, BW, egg weight, egg yolk weight, egg production, Haugh units, liver mass, plasma, and hepatic cholesterol concentrations did not differ as a function of plant sterol supplementation. Egg cholesterol concentrations (mg/g) fluctuated during the 6-wk experimental period. At wk 6, a minor reduction in egg yolk cholesterol concentration (mg per g of yolk, P < 0.05, vs. control) was observed in hens fed 1 and 2% cholesterol-enriched diets, respectively. However, such result failed to affect total egg cholesterol content. No statistical difference was observed across treatments over 6 wk. Neither cholesterol absorption rates nor synthesis differed as a function of treatment. Results suggested that overall cholesterol content in egg yolk was not affected by feeding hens plant sterol-enriched diets over 6 wk.

Abstract The evolution of the human diet over the past 10,000 years from a Paleolithic diet to our current modern pattern of intake has resulted in profound changes in feeding behavior. Shifts have occurred from diets high in fruits, vegetables, lean meats, and seafood to processed foods high in sodium and hydrogenated fats and low in fiber. These dietary changes have adversely affected dietary parameters known to be related to health, resulting in an increase in obesity and chronic disease, including cardiovascular disease (CVD), diabetes, and cancer. Some intervention trials using Paleolithic dietary patterns have shown promising results with favorable changes in CVD and diabetes risk factors. However, such benefits may be offset by disadvantages of the Paleolithic diet, which is low in vitamin D and calcium and high in fish potentially containing environmental toxins. More advantageous would be promotion of foods and food ingredients from our ancestral era that have been shown to possess health benefits in the form of functional foods. Many studies have investigated the health benefits of various functional food ingredients, including omega-3 fatty acids, polyphenols, fiber, and plant sterols. These bioactive compounds may help to prevent and reduce incidence of chronic diseases, which in turn could lead to health cost savings ranging from $2 to $3 billion per year as estimated by case studies using omega-3 and plant sterols as examples. Thus, public health benefits should result from promotion of the positive components of Paleolithic diets as functional foods.

Summary For many years, both the medical community and the general public have incorrectly associated eggs with high serum cholesterol and being deleterious to health, even though cholesterol is an essential component of cells and organisms. It is now acknowledged that the original studies purporting to show a linear relation between cholesterol intake and coronary heart disease (CHD) may have contained fundamental study design flaws, including conflated cholesterol and saturated fat consumption rates and inaccurately assessed actual dietary intake of fats by study subjects. Newer and more accurate trials, such as that conducted by Frank B. Hu of the Harvard School of Public Health (1999), have shown that consumption of up to seven eggs per week is harmonious with a healthful diet, except in male patients with diabetes for whom an association in higher egg intake and CHD was shown. The degree to which serum cholesterol is increased by dietary cholesterol depends upon whether the individual's cholesterol synthesis is stimulated or down-regulated by such increased intake, and the extent to which each of these phenomena occurs varies from person to person. Several recent studies have shed additional light on the specific interplay between dietary cholesterol and cardiovascular health risk. It is evident that the dynamics of cholesterol homeostasis, and of development of CHD, are extremely complex and multifactorial. In summary, the earlier purported adverse relationship between dietary cholesterol and heart disease risk was likely largely over-exaggerated.

Dietary energy restriction (ER) offers certain health benefits, particularly when ER is controlled through manipulation of dietary fats. Our hypothesis is that cellular immunity is modulated by dietary ER. Furthermore, we believe that the immune response may differ between spleen and colon because their lymphatic and vascular organization is different. The objective of the study was to test this hypothesis by determining the effects of dietary ER through manipulation of energy intake from high-fat (HF) diets on the expression and frequency of the CD4(+)(T-helper/T-inducer) and CD8(+)(T-cytotoxic/T-suppressor) cells, CD45RA (B-cell-specific marker), and immunoglobulins (Ig) A-, G-, and M-bearing cells in spleen and colon in rats by immunohistochemical method. Rats fed the HF diet had a significantly (P <.05) reduced number of immune cells as compared with those fed ER diets. Energy-restricted diet-fed rats showed higher (P <.05) numbers of CD4(+), CD8(+), IgA, IgM, IgG, and CD45RA cells in spleen and CD4(+), IgA, and CD45RA cells in colonic lamina propria. The IgA-containing cells were markedly higher in the colon compared with the spleen. No change occurred in the number of IgM- and IgG-containing cells in colonic tissues between groups, except for the 20% ER group where IgM-labeled cells were higher (P <.05) compared with HF and 40% ER groups. These findings suggest that ER may modulate adaptive immune function and that CD4(+) and IgA cells may serve as biological indicators for dietary energy-modulated immunoresponse in spleen and colon, respectively.

The mushroom Inonotus obliquus (Chaga), Senega root (Polygala senega) and cranberry (Viburnum trilobum) bark have been used for their medicinal properties in many parts of the world. The purpose of the present study was to develop a cell screening cytokine assay to assess the anti-inflammatory effect of the mushroom Inonotus obliquus (Chaga), Polygala Senega (Senega) and Viburnum trilobum (Cranberry) bark extracts in LPS induced murine macrophage RAW 164.7 cells. Four fractions were obtained;(80% ethanol extracted;Fa),(Water-soluble polysaccharide fraction;Fb),(Polyphenolic fraction; Fc) and (ETOAc/H(2)O extracted fraction;Fd). These extract fractions were tested in the cell screening system at 50,100 and 500 ug/ml for their ability to inhibit LPS induced inflammatory cytokines IL-1ss, TNFalpha and IL-6. Supernatants from LPS alone treated cells were used as control. The cytokines in the cell culture supernatants following treatments with extract fractions were quantified by ELISA method, using 96 well ELISA plates. All fractions of the extracts significantly inhibited (p<0.05) the levels of IL-1ss, IL-6 and TNFalpha except the polyphenolic Fc fraction of Senega which showed an increased production of IL-6. Furthermore, each fraction showed a dose dependant anti-inflammatory effect. Nitric oxide production was not affected by cranberry and senega, while Chaga significantly reduced NO production in murine macrophage cell assay.

Preliminary evidence suggests that consumption of Porphyridium cruentum (PC) biomass results in hypocholesterolaemic effects; however, mechanisms responsible have not been elucidated. The aim of the present study was to determine whether PC biomass lowers circulating cholesterol concentrations, dose dependently, in hamsters fed hypercholesterolaemic diets for 28 d and determine whether cholesterol biosynthesis is affected. Biomass added to diets at 2.5, 5 and 10 % resulted in 14, 38 and 53 % reductions (P < 0.001) in total plasma cholesterol, respectively, compared with a control diet. Similarly, non-HDL-cholesterol concentrations in the 5 and 10 % PC groups were reduced (P < 0.001) 28 and 45 %, respectively, v. controls. These effects were unrelated to cholesterol fractional synthesis rate (FSR), as this did not differ between either treatment or control animals. PC consumption had no effect on food intake, plasma glucose concentrations or energy expenditure, but percentage of body fat was lower (P < 0.001) in the 5 and 10 % PC groups compared with controls. These data show that PC reduces total plasma cholesterol and non-HDL-cholesterol when incorporated into the diet at levels as low as 2.5 %. The mechanism of action for this reduction may be related to increased excretion since food intakes and cholesterol FSR were not reduced in the animals receiving the PC. In conclusion, the use of PC biomass reduces circulating cholesterol, dose dependently, in hypercholesterolaemic hamsters but not via reductions in cholesterol FSR. There is potential for the use of this biomass as a functional ingredient to aid in the management of blood cholesterol concentrations.

Phytosterol and stanol (or phytosterols) consumption reduces intestinal cholesterol absorption, leading to decreased blood LDL-cholesterol levels and lowered cardiovascular disease risk. However, other biological roles for plant sterols and stanols have also been proposed. The objective of this review is to critically examine results from recent research regarding the potential effects and mechanisms of action of phytosterols on forms of cancer. Considerable emerging evidence supports the inhibitory actions of phytosterols on lung, stomach, as well as ovarian and breast cancer. Phytosterols seem to act through multiple mechanisms of action, including inhibition of carcinogen production, cancer-cell growth, angiogenesis, invasion and metastasis, and through the promotion of apoptosis of cancerous cells. Phytosterol consumption may also increase the activity of antioxidant enzymes and thereby reduce oxidative stress. In addition to altering cell-membrane structure and function, phytosterols probably promote apoptosis by lowering blood cholesterol levels. Moreover, consumption of phytosterols by healthy humans at the recommended level of 2 g per day does not cause any major health risks. In summary, mounting evidence supports a role for phytosterols in protecting against cancer development. Hence, phytosterols could be incorporated in diet not only to lower the cardiovascular disease risk, but also to potentially prevent cancer development.European Journal of Clinical Nutrition advance online publication, 3 June 2009; doi:10.1038/ejcn.2009.29.

Sugar cane policosanols (SCP) have been shown to exert antioxidant properties in various studies conducted in Cuba. Independent studies have since reported no significant effect of SCP consumption on oxidized LDL levels. The objective of the present study was to confirm the effects of Cuban SCP on LDL oxidation using a high-precision capture ELISA procedure in hypercholesterolemic individuals. Twenty-one otherwise healthy hypercholesterolemic men and post-menopausal women participated in a randomized double blind crossover study where they received 10 mg/day of policosanol or a placebo incorporated in margarine as an evening snack for a period of 28 days. Subjects maintained their usual dietary and exercise habits throughout the duration of the study. Blood was collected on the first as well as the last 2 days of the trial. LDL oxidation was measured from plasma using a solid phase two-site enzyme immunoassay. A lack of effect of SCP was observed on LDL cholesterol levels, as well as no difference in LDL oxidation between the SCP treatment and placebo at the end of the intervention period. Subject body weights remained stable throughout the study and showed no significant correlation with LDL oxidation levels. Absolute levels of plasma LDL cholesterol were significantly (P < 0.05) correlated with plasma concentrations of oxidized LDL. The findings of the present study suggest that SCP do not significantly affect LDL oxidation. Our results align with results of recent policosanol research questioning the efficacy of these natural extracts as cardio-protective agents.