Phytosterol composition of nuts and seeds commonly consumed in the United States

Online LC-GC-based analysis of minor lipids in various tree nuts and peanuts

As information on free sterols/stanols and steryl/stanyl esters in nuts is lacking, the compositions and contents of these lipid constituents in ten different nut types were analyzed. The applied approach was based on online liquid chromatography-gas chromatography and enabled the simultaneous analysis of free sterols/stanols and individual steryl/stanyl fatty acid esters, and additionally of tocopherols and squalene. Total contents of free sterols/stanols ranged from 0.62 mg/g nut in hazelnuts to 1.61 mg/g nut in pistachios, with sitosterol as the predominant compound. Total contents of steryl/stanyl fatty acid esters were in the range of 0.11-1.26 mg/g nut, being lowest in Brazil nuts and highest in pistachios. There were considerable differences between the various nut types not only regarding the contents, but also the compositions of both classes. The levels of tocopherols were highest in pine nuts (0.33 mg/g nut); those of squalene were remarkably high in Brazil nuts (1.11 mg/g nut).

Evaluating and adapting the Mediterranean diet for non-Mediterranean populations: a critical appraisal

This review outlines the limitations of current techniques for evaluating the Mediterranean diet in Mediterranean versus non-Mediterranean populations. Differences between the two populations with regard to the foods that are available, food processing and preparation techniques, and eating and lifestyle habits may influence the implementation and effects of a Mediterranean diet in non-Mediterranean regions. For example, the composition of food groups may vary significantly, due to differences in the specific foods within a food group and to differences in aspects of food production and preparation. Notable differences between the diets of Mediterranean versus non-Mediterranean populations include the source of monounsaturated fatty acids (olive oil versus meat), the amount of vegetables consumed and their manner of preparation, the source of alcohol (wine versus other) and the pattern of intake, and the types of meat and dairy products consumed. Lifestyle factors such as meal patterns and exposure to sunlight may also act as confounding factors when the overall benefits of a Mediterranean diet are assessed. Improving the calculation of Mediterranean diet scores and measuring plasma nutrient levels may help mitigate the effects of confounders. These considerations could have important health implications when a Mediterranean diet is implemented by non-Mediterranean populations.

Nutritional evaluation and health promoting activities of nuts and seeds cultivated in Greece

Available data suggest that genetic as well as environmental factors may influence nuts and seeds nutrients content. In this context nuts and seeds cultivated in Greece were studied. Macronutrients content was in agreement with that from other areas. Total phenolics content was in the range of 43.0 ± 2.1-1512.7 ± 60.7 mg GAE/100 g for chestnut and walnut, respectively. Thirteen to 22 individual phenolics were identified in the studied species. Oleanolic acid was in the range of 0.10-9.03 mg/100 g. Pumpkin seeds contained the higher squalene content (71.6 mg/100 g). β-Sitosterol predominated in all samples except pumpkin seeds. Tocopherols ranged from 8.9 mg/100 g (chestnut) to 29.3 mg/100 g (almond). Nuts and seeds hydrophilic extracts at quantities corresponding to the estimated daily consumption by the Greeks succeeded in inhibiting LDL oxidation in vitro by increasing lag time 1.1-14.1 times. One serving of nuts or seeds may cover a significant fraction of health promoting microconstituents daily intake.

In vitro antimicrobial activity of pistachio (Pistacia vera L.) polyphenols

We investigated the antimicrobial properties of polyphenol-rich fractions derived from raw shelled and roasted salted pistachios. American Type Culture Collection (ATCC), food and clinical isolates, of Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Pseudomonas mirabilis), Gram-positive bacteria (Listeria monocytogenes, Enterococcus hirae, Enterococcus faecium, Bacillus subtilis, Staphylococcus epidermidis, Staphylococcus aureus), the yeasts Candida albicans and Candida parapsilosis and the fungus Aspergillus niger were used. Pistachio extracts were active against Gram-positive bacteria with a bactericidal effect observed against L. monocytogenes (ATCC strains and food isolates), S. aureus and MRSA clinical isolates. Extracts from raw shelled pistachios were more active than those from roasted salted pistachios. The bactericidal activity of pistachio extracts could be used to help control the growth of some microorganisms in foods to improve safety and may find application as a topical treatment for S. aureus.

Sterol composition of shellfish species commonly consumed in the United States

Background

Shellfish can be a component of a healthy diet due to a low fat and high protein content, but the cholesterol content of some species is often cited as a reason to limit their consumption. Data on levels of non-cholesterol sterols in commonly consumed species are lacking.

Objective

Shellfish were sampled and analyzed to update sterol data in the United States Department of Agriculture (USDA) National Nutrient Database for Standard Reference.

Design

Using a nationwide sampling plan, raw shrimp and sea scallops, canned clams, and steamed oysters, blue crab, and lobster were sampled from 12 statistically selected supermarkets across the United States in 2007–08. For each species, four composites were analyzed, each comprised of samples from three locations; shrimp and scallops from six single locations were also analyzed separately. Using validated analytical methodology, 14 sterols were determined in total lipid extracts after saponification and derivatization to trimethylsilyethers, using gas chromatography for quantitation and mass spectrometry for confirmation of components.

Results

Crab, lobster, and shrimp contained significant cholesterol (96.2–27 mg/100 g); scallops and clams had the lowest concentrations (23.4–30.1 mg/100 g). Variability in cholesterol among single-location samples of shrimp was low. The major sterols in the mollusks were brassicasterol (12.6–45.6 mg/100 g) and 24-methylenecholesterol (16.7–41.9 mg/100 g), with the highest concentrations in oysters. Total non-cholesterol sterols were 46.5–75.6 mg/100 g in five single-location scallops samples, but 107 mg/100 g in the sixth, with cholesterol also higher in that sample. Other prominent non-cholesterol sterols in mollusks were 22-dehydrocholesterol, isofucosterol, clionasterol, campesterol, and 24-norcholesta-5,22-diene-3β-ol (4–21 mg/100 g).

Conclusions

The presence of a wide range of sterols, including isomeric forms, in shellfish makes the analysis and quantitation of sterols in marine species more complex than in animal and plant tissues. The detailed sterol composition reported herein provides data that may be useful in research on the impact of shellfish consumption on dietary risk factors.

Pistachio nuts: composition and potential health benefits

The pistachio is a nutrient-dense nut with a heart-healthy fatty-acid profile as well as protein, dietary fiber, potassium, magnesium, vitamin K, γ-tocopherol, and a number of phytochemicals. The pistachio's unique green and purple kernel color is a result of its lutein and anthocyanin content. Among nuts, pistachios contain the highest levels of potassium, γ-tocopherol, vitamin K, phytosterols, and xanthophyll carotenoids. Five published randomized cardiovascular trials have shown that pistachios promote heart-healthy blood lipid profiles. Exploratory clinical studies suggest that pistachios help maintain healthy antioxidant and anti-inflammatory activity, glycemic control, and endothelial function. When consumed in moderation, pistachios may help control body weight because of their satiety and satiation effects and their reduced net metabolizable energy content. One study with subjects in a weight-loss program demonstrated lower body mass index and triglyceride levels in individuals who consumed pistachios compared with those who consumed an isocaloric pretzel snack. Emerging research suggests that the addition of pistachios to high-glycemic meals may lower the overall postprandial glycemic response. This review examines the nutrients and phytochemicals in pistachios as well as the potential health effects of these nuts.

Comparison of the chemical compositions and nutritive values of various pumpkin (Cucurbitaceae) species and parts

Pumpkins have considerable variation in nutrient contents depending on the cultivation environment, species, or part. In this study, the general chemical compositions and some bioactive components, such as tocopherols, carotenoids, and β-sitosterol, were analyzed in three major species of pumpkin (Cucurbitaceae pepo, C. moschata, and C. maxima) grown in Korea and also in three parts (peel, flesh, and seed) of each pumpkin species. C. maxima had significantly more carbohydrate, protein, fat, and fiber than C. pepo or C. moschata (P < 0.05). The moisture content as well as the amino acid and arginine contents in all parts of the pumpkin was highest in C. pepo. The major fatty acids in the seeds were palmitic, stearic, oleic, and linoleic acids. C. pepo and C. moschata seeds had significantly more γ-tocopherol than C. maxima, whose seeds had the highest β-carotene content. C. pepo seeds had significantly more β-sitosterol than the others. Nutrient compositions differed considerably among the pumpkin species and parts. These results will be useful in updating the nutrient compositions of pumpkin in the Korean food composition database. Additional analyses of various pumpkins grown in different years and in different areas of Korea are needed.

Tree nut phytochemicals: composition, antioxidant capacity, bioactivity, impact factors. A systematic review of almonds, Brazils, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts

Tree nuts contain an array of phytochemicals including carotenoids, phenolic acids, phytosterols and polyphenolic compounds such as flavonoids, proanthocyanidins (PAC) and stilbenes, all of which are included in nutrient databases, as well as phytates, sphingolipids, alkylphenols and lignans, which are not. The phytochemical content of tree nuts can vary considerably by nut type, genotype, pre- and post-harvest conditions, as well as storage conditions. Genotype affects phenolic acids, flavonoids, stilbenes and phytosterols, but data are lacking for many other phytochemical classes. During the roasting process, tree nut isoflavones, flavanols and flavonols were found to be more resistant to heat than the anthocyanins, PAC and trans-resveratrol. The choice of solvents used for extracting polyphenols and phytosterols significantly affects their quantification, and studies validating these methods for tree nut phytochemicals are lacking. The phytochemicals found in tree nuts have been associated with antioxidant, anti-inflammatory, anti-proliferative, antiviral, chemopreventive and hypocholesterolaemic actions, all of which are known to affect the initiation and progression of several pathogenic processes. While tree nut phytochemicals are bioaccessible and bioavailable in humans, the number of intervention trials conducted to date is limited. The objectives of the present review are to summarise tree nut: (1) phytochemicals; (2) phytochemical content included in nutrient databases and current publications; (3) phytochemicals affected by pre- and post-harvest conditions and analytical methodology; and (4) bioactivity and health benefits in humans.

Update on the healthful lipid constituents of commercially important tree nuts

Uncharacteristic of most whole foods, the major component of tree nuts is lipid; surprisingly, information on the lipid constituents in tree nuts has been sporadic and, for the most part, not well reported. Most published papers focus on only one nut type, or those that report a cultivar lack a quality control program, thus making data comparisons difficult. The present study was designed to quantify the healthful lipid constituents of 10 different types of commercially important tree nuts (i.e., almonds, black walnuts, Brazil nuts, cashews, English walnuts, hazelnuts, macadamias, pecans, pine nuts, and pistachios) according to standardized, validated methods. The total lipid content of each nut type ranged from 44.4 ± 1.9% for cashews to 77.1 ± 1.7% for macadamias. As expected, the major fatty acids present in the tree nuts were unsaturated: oleic (18:1 ω9) and linoleic (18:2 ω6) acids. A majority of the lipid extracts contained <10% saturated fatty acids with the exceptions of Brazil nuts (24.5%), cashews (20.9%), macadamias (17.1%), and pistachios (13.3%). The total tocopherol (T) content ranged from 1.60 ± 1.27 mg/100 g nutmeat in macadamias to 32.99 ± 0.78 in black walnuts. The predominant T isomers in the nut types were α- and γ-T. Tocotrienols were also detected, but only in 6 of the 10 nut types (i.e., Brazil nut, cashews, English walnuts, macadamias, pine nuts, and pistachios). In most cases, total phytosterol contents were greater in the present study than reported in peer-reviewed journal papers and the USDA National Nutrient Database for Standard Reference, which is attributed to total lipid extraction and the inclusion of steryl glucosides in the analysis; the levels were highest for pistachios (301.8 ± 15.4 mg/100 g nutmeat) and pine nuts (271.7 ± 9.1 mg/100 g nutmeat). Minor sterols were also quantified and identified using GC-FID and GC-MS techniques.

The effect of pumpkin (Cucurbita pepo L) seeds and L-arginine supplementation on serum lipid concentrations in atherogenic rats

The present study aimed to examine the effect of pumpkin (Cucurbita pepo L.) seeds supplementation on atherogenic diet-induced atherosclerosis. Rat were divided into two main groups , normal control and atherogenic control rats , each group composed of three subgroups one of them supplemented with 2% arginine in drinking water and the other supplemented with pumpkin seeds in diet at a concentration equivalent to 2% arginine. Supplementation continued for 37 days. Atherogenic rats supplemented with pumpkin seeds showed a significant decrease (p<0.001) in their serum concentrations of total cholesterol and LDL - C as they dropped from 4.89 mmol / L to 2.55 mmol /L and from 3.33 mmol / L to 0.70 mmol / L respectively. Serum concentrations of HDL-C were also significantly elevated in the same group. Although, atherogenic rats supplemented with 2% arginine showed significant increase in serum concentration of HDL-C, no significant changes were observed in their serum concentrations of total cholesterol and LDL-C. Our results showed that treatment of atherogenic rats with pumpkin seeds significantly decreased serum concentrations of TC and LDL-C. Our findings suggest that pumpkin seeds supplementation has a protective effect against atherogenic rats and this protective effect was not attributed to the high arginine concentrations in pumpkin seeds.

Vitamin D mushrooms: comparison of the composition of button mushrooms (Agaricus bisporus) treated postharvest with UVB light or sunlight

This study compared the compositional changes in mushrooms exposed to sunlight with those occurring after commercial ultraviolet (UV) light processing. Button mushrooms (75 kg) were processed in the presence or absence of UVB light; a third group was exposed to direct sunlight. Mushroom composition was evaluated using chemical analyses. Vitamin D concentrations were 5, 410, and 374 μg/100 g (dw) in control, UVB, and sunlight groups, respectively. On a dry weight basis, no significant changes in vitamin C, folate, vitamins B(6), vitamin B(5), riboflavin, niacin, amino acids, fatty acids, ergosterol, or agaritine were observed following UVB processing. Sunlight exposure resulted in a 26% loss of riboflavin, evidence of folate oxidation, and unexplained increases in ergosterol (9.5%). It was concluded that compositional effects of UVB light are limited to changes in vitamin D and show no detrimental changes relative to natural sunlight exposure and, therefore, provide important information relevant to the suitability and safety of UVB light technology for vitamin D enhanced mushrooms.

Vitamin D and sterol composition of 10 types of mushrooms from retail suppliers in the United States

Vitamin D(2) (ergocalciferol) and sterols were analyzed in mushrooms sampled nationwide in the United States to update the USDA Nutrient Database for Standard Reference. Vitamin D(2) was assayed using HPLC with [(3)H]-vitamin D(3) internal standard and sterols by GC-FID mass spectrometric (MS) confirmation. Vitamin D(2) was low (0.1-0.3 μg/100 g) in Agaricus bisporus (white button, crimini, portabella) and enoki, moderate in shiitake and oyster (0.4-0.7 μg/100 g), and high in morel, chanterelle, maitake (5.2-28.1 μg/100 g) and UV-treated portabella (3.4-20.9 μg/100 g), with significant variability among composites for some types. Ergosterol (mg/100 g) was highest in maitake and shiitake (79.2, 84.9) and lowest in morel and enoki (26.3, 35.5); the range was <10 mg/100 g among white button composites but 12-50 mg/100 g among samples of other types. All mushrooms contained ergosta-5,7-dienol (22,23-dihydroergosterol) (3.53-18.0 mg/100 g) and (except morel) ergosta-7-enol. Only morel contained brassicasterol (28.6 mg/100 g) and campesterol (1.23-4.54 mg/100 g) and no ergosta-7,22-dienol. MS was critical in distinguishing campesterol from ergosta-7,22-dienol.

Characteristics and pathways of bioactive 4-desmethylsterols, triterpene alcohols and 4α-monomethylsterols, from developing Tunisian cultivars and wild peanut (Arachis hypogaea L.)

Seven 4-desmethylsterols, five triterpene alcohols and three 4α-monomethylsterols were identified by GC-MS during the development of wild peanut, which is Arbi (AraA), and cultivars peanut, which are Trabelsia (AraT) and Chounfakhi (AraC). Our results showed that the maximum level of 4-desmethylsterols (881.07 mg/100 g of oil) was reached at 12 days after flowering (DAF) date of peanut plant in AraA, as well as the highest level of triterpene alcohols (31.51 mg/100 g of oil) was reached at 23 DAF in AraA, whilst, the highest level of 4α-monomethylsterols (15.11 mg/100 g of oil) was reached at 41 DAF in AraC. Herein, the level of triterpene alcohols and 4α-monomethylsterols was overwhelmed by the amount of 4-desmethylsterols at each stage of peanut maturity. Differences were observed in each sterol contents among the studied cultivars and wild one especially in immature stage.

Chemical composition and biological activities of Arachis species

Arachis hypogaea , known as the peanut, is native to South America. Peanut contains several active components including flavonoids, phenolic acids, phytosterols, alkaloids, and stilbenes. Some therapeutic effects have been reported for peanut seed extracts, such as antioxidative, antibacterial, antifungal, and anti-inflammatory activities. This paper aims to give an overview of the chemical composition, focusing on secondary metabolites, and of the biological activity of A. hypogaea, to stimulate new studies about species of the Arachis genus.

Nuts: anti-atherogenic food?

The prevalence of cardiovascular disease as the leading cause of morbidity and mortality is increasing worldwide. This fact is mainly attributed to the modern lifestyle with predominant characteristics the change of dietary habits and the reduced physical activity which lead to metabolic disorders such as obesity and diabetes. Therefore, drastic dietary interventions are considered necessary in order to reduce cardiovascular risk. Nuts, as a nutritional component have drawn particular attention, due to their beneficial cardiovascular properties derived from their nutrient composition. This is a comprehensive review concerning the potential general effects of nuts. It includes data from older large epidemiologic studies as well as recent significant information from clinical trials regarding this topic. All studies conclude that nuts can play an important role as part of a healthy diet in order to minimize cardiovascular risk and obtain multiple health benefits.

Development of a cell-based, high-throughput screening assay for cholesterol efflux using a fluorescent mimic of cholesterol

Reverse cholesterol transport is the process by which extrahepatic cells, including macrophage-derived foam cells in arterial atherosclerotic plaque, transport excessive cholesterol back to the liver for bile acid synthesis and excretion, thus lowering the peripheral lipid burden. Cholesterol efflux from peripheral cells is the first step in this process, and finding drugs and interventions that promote this event is an important endeavor. Radioisotope-labeled cholesterol traditionally has been employed in measuring efflux efficiency, but this reagent has limitations for high-throughput screening. We developed an alternative method to measure cholesterol efflux in macrophage-derived foam cells using a novel fluorescent cholesterol mimic comprising the Pennsylvania Green fluorophore, attached by a linker containing a glutamic acid residue, to a derivative of N-alkyl-3β-cholesterylamine. Compared with the traditional radioisotope-based assay, this fluorescence-based assay gave similar results in the presence of known modulators of cholesterol efflux, such as cyclic AMP, and different cholesterol acceptors. When the fluorescent probe was employed in a high-throughput screening format, a variety of chemicals and bioactive compounds with known and unknown effects on cholesterol efflux could be tested simultaneously by plate-reader in a short period of time. Treatment of THP-1-derived macrophages with inhibitors of the membrane transporter ATP-binding cassette A1, such as glyburide or a specific antibody, significantly reduced the export of this fluorescent compound, indicating that ATP-binding cassette A1 represents the primary mediator of its cellular efflux. This fluorescent mimic of cholesterol provides a safe, sensitive, and reproducible alternative to radioactive assays in efflux experiments and has great potential as a valuable tool when incorporated into a drug discovery program.

Further insight into the latex metabolite profile of Ficus carica

Latex is a sticky emulsion that exudes upon damage from specialized canals from several plants. It contains several biologically active compounds, such as phytosterols, fatty acids, and amino acids. In plants, these compounds are involved in the interaction between plants, insects, and the environment. Despite its chemical, biological, and ecological importance, Ficus carica latex is still poorly studied. To improve the knowledge on the metabolite profile of this matrix, a targeted metabolite analysis was performed in a representative sample from F. carica latex. Seven phytosterols were determined by gas chromatography-ion trap mass spectrometry (GC-ITMS) and high-performance liquid chromatography coupled to diode array detection (HPLC-DAD), with β-sitosterol and lupeol being the compounds present in higher concentrations (ca. 54 and 14%, respectively). A total of 18 fatty acids were characterized by GC-ITMS, being essentially represented by saturated fatty acids (ca. 86.4% of total fatty acids). A total of 13 free amino acids were also identified by high-performance liquid chromatography coupled to ultraviolet-visible spectroscopy (HPLC/UV-vis), and cysteine and tyrosine were the major ones (ca. 38.7 and 31.4%, respectively). In humans, phytosterols and some polyunsaturated fatty acids, such as linoleic acid, are known for their anticarcinogenic properties. With regard to amino acids, some of them, such as glycine, are neurotransmitters. Our results reveal the presence of a wide diversity of compounds, from distinct classes, in F. carica latex, possessing various potential pharmacological activities; thus, its biological potential appears to be worth further exploring.

Commercial peanut (Arachis hypogaea L.) cultivars in the United States: phytosterol composition

Phytosterols in commercially grown Runner, Virginia, and Spanish peanuts (n = 221) from 2005 and 2006 were quantified by a combination of acid hydrolysis and alkaline saponification steps followed by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry analysis of the trimethylsilyl derivatives. Δ(5)-Avenasterol, which partially degrades during acid hydrolysis, was quantified after alkaline saponification plus direct analysis of the steryl glucosides isolated by solid-phase extraction. β-Sitosterol, Δ(5)-avenasterol, campesterol, and stigmasterol were identified in peanut lipid extracts as the dominant sterols by retention time mapping and mass spectra with recoveries ∼99%. Clerosterol, Δ(5,24(25))-stigmastadienol, Δ(7)-sitosterol + cycloartenol, and one unidentified sterol were also present but at low levels. Free and esterified phytosterols accounted for ∼80% of the total sterols determined; the remainder was attributed to steryl glucosides. The total sterol level in Spanish market type peanuts (144.1 ± 5.3 mg/100 g) was significantly greater than both Runners (127.5 ± 6.3 mg/100 g) and Virginias (129.3 ± 6.9 mg/100 g) (P < 0.05). Tamspan 90 (146.9 mg/100 g) followed by OLIN (138.5 mg/100 g) showed the highest total sterol content among the cultivars examined. Cultivar effects were strongly significant (P < 0.001) for all phytosterols, whereas production year effects were strongly significant (P < 0.001) for Δ(5)-avenasterol, Δ(5,24(25))-stigmastadienol, and the combined quantities of Δ(7)-sitosterol + cycloartenol, which coeluted. Cultivar × year interactions were strongly significant (P < 0.001) in all sterols except for Δ(7)-sitosterol + cycloartenol (P < 0.01). Total phytosterol contents were markedly higher than those reported in the existing literature for Runner and Virginia type peanuts, partially attributed to the inclusion of steryl glucosides in the analysis.

Nuts, metabolic syndrome and diabetes

The ability of nuts to improve the blood lipid profile and reduce the risk of CHD is now well established. The interest that health effects of nuts have gained recently has brought the possible benefits of consuming nuts, such as improvement in the conditions of the metabolic syndrome, and their potential to prevent and control diabetes into focus. Results from cohort studies have associated nut consumption with a reduced risk of developing diabetes and CVD. However, few randomised controlled trials have assessed the effect of nuts on diabetes control, and those that have been undertaken have shown improvements in blood lipids but not in the glycaemic control. Diabetes agencies are increasingly recognising the importance of controlling postprandial glycaemia fluctuations. Acute feeding studies indicate that nuts have minimal effects on rising postprandial blood glucose levels when eaten alone, and diminish the postprandial glycaemic response when consumed with high-glycaemic index carbohydrate foods in both normoglycaemic and type 2 diabetic individuals. Nuts have a healthy nutritional profile, high in MUFA and PUFA, are a good source of vegetable protein and are rich in fibre, vitamins and minerals. Incorporation of nuts in the diet may therefore improve the overall nutritional quality of the diet. While more research is required to establish the ability of nuts to improve glycaemic control in the long run, early data indicate that the inclusion of nuts in the diets of individuals with diabetes and the metabolic syndrome is warranted, in view of their potential to reduce CHD risk.

Evolution of the human diet: linking our ancestral diet to modern functional foods as a means of chronic disease prevention

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.

Phytosterol-deficient and high-phytosterol diets developed for controlled feeding studies

Phytosterols reduce cholesterol absorption and low-density lipoprotein cholesterol concentrations, but the quantity and physiological significance of phytosterols in common diets are generally unknown because nutrient databases do not contain comprehensive phytosterol data. The primary aim of this study was to design prototype phytosterol-deficient and high-phytosterol diets for use in controlled feeding studies of the influence of phytosterols on health. A second aim was to quantify the phytosterol content of these prototype diets and three other diets consumed in the United States. This study was conducted from June 2001 to September 2008 and involved designing, preparing, and then analyzing five different diets: an experimental phytosterol-deficient control diet, a relatively high-phytosterol diet based on the Dietary Approaches to Stop Hypertension diet, American Heart Association diet, Atkins lifetime maintenance plan, and a vegan diet. A single day of meals for each diet was homogenized and the resulting composites were analyzed for free, esterified, and glycosylated phytosterols by gas chromatography. Independent samples t tests were used to compare the diets' total phytosterol content. The total phytosterol content of the experimental phytosterol-deficient diet was 64 mg/2,000 kcal, with progressively larger quantities in Atkins, American Heart Association, vegan, and the high-phytosterol Dietary Approaches to Stop Hypertension diet (163, 340, 445, and 500 mg/2,000 kcal, respectively). Glycosylated phytosterols, which are often excluded from phytosterol analyses, comprised 15.9%+/-5.9% of total phytosterols. In summary, phytosterol-deficient and high-phytosterol diets that conform to recommended macronutrient guidelines and are palatable can now be used in controlled feeding studies.