Guidelines for the design, conduct and reporting of human intervention studies to evaluate the health benefits of foods.

There is substantial evidence to link what we eat to the reduction of the risk of major chronic diseases and/or the improvement of functions. Thus, it is important for public health agencies and the food industry to facilitate the consumption of foods with particular health benefits by providing consumer products and messages based on scientific evidence. Although fragmentary advice is available from a range of sources, there is a lack of comprehensive scientific guidelines for the design, conduct and reporting of human intervention studies to evaluate the health benefits of foods.

The proportion of lycopene isomers in human plasma is modulated by lycopene isomer profile in the meal but not by lycopene preparation.

Dietary lycopene consists mostly of the (all-E) isomer. Upon absorption, (all-E) lycopene undergoes isomerisation into various (Z)-isomers. Because these isomers offer potentially better health benefits than the (all-E) isomer, the aim of the present study was to investigate if the profile of lycopene isomers in intestinal lipoproteins is affected by the profile of lycopene isomers in the meal and by the tomato preparation.

Lycopene bioavailability and metabolism in humans: an accelerator mass spectrometry study.

Background: To our knowledge, there is no direct information on lycopene metabolism in humans.

Objective: The objective of this study was to quantify the long-term human bioavailability of lycopene in plasma and skin after a single dose of (14)C-lycopene and to profile the metabolites formed.

Design: We preselected 2 male subjects as lycopene absorbers and gave them an oral dose of 10 mg synthetic lycopene combined with ≈6 μg [6,6',7,7'-(14)C]lycopene (≈30,000 Bq; 92% trans lycopene).

The biological relevance of direct antioxidant effects of polyphenols for cardiovascular health in humans is not established.

Human studies provide evidence for beneficial effects of polyphenol-rich foods on cardiovascular health. The antioxidant activity of polyphenols potentially explains these effects, but is the antioxidant activity a reliable predictor for these effects? An International Life Sciences Institute Europe working group addressed this question and explored the potential of antioxidant claims for polyphenols in relation to cardiovascular health by using the so-called Process for the Assessment of Scientific Support for Claims on Foods project criteria. In this process, analytical aspects of polyphenols, their occurrence in foods, dietary intake, and bioavailability were reviewed.

Lycopene isomerisation takes place within enterocytes during absorption in human subjects.

Lycopene in fruits and vegetables occurs mostly (80-97 %) in the all-E configuration, whereas a considerable proportion of lycopene in the human body is present as Z-isomers. The Z-isomers offer potentially better health benefits and show improved antioxidant activity in vitro when compared with the all-E-isomer. The absorption of dietary lycopene is a complex process involving transfer of the carotenoid from the food matrix into micelles, uptake by enterocytes, packaging into chylomicrons and finally secretion into plasma.

Bioaccessibility of carotenoids and vitamin E from their main dietary sources.

Vitamin E and carotenoids are fat-soluble microconstituents that may exert beneficial effects in humans, including protection against cancer, cardiovascular diseases, and age-related eye diseases. Their bioavailability is influenced by various factors including food matrix, formulation, and food processing. Since human studies are labor-intensive, time-consuming, and expensive, the in vitro model used in this study is increasingly being used to estimate bioaccessibility of these microconstituents.

Skin bioavailability of dietary vitamin E, carotenoids, polyphenols, vitamin C, zinc and selenium.

Dietary bioactive compounds (vitamin E, carotenoids, polyphenols, vitamin C, Se and Zn) have beneficial effects on skin health. The classical route of administration of active compounds is by topical application direct to the skin, and manufacturers have substantial experience of formulating ingredients in this field. However, the use of functional foods and oral supplements for improving skin condition is increasing.

Enhanced bioavailability of zeaxanthin in a milk-based formulation of wolfberry (Gou Qi Zi; Fructus barbarum L.).

The carotenoid zeaxanthin is concentrated within the macula. Increased macular zeaxanthin is suggested to lower the risk of age-related macular degeneration. The small red berry, wolfberry (Fructus barbarum L.

beta3-adrenoceptor agonist prevents alterations of muscle diacylglycerol and adipose tissue phospholipids induced by a cafeteria diet.

BACKGROUND: Insulin resistance induced by a high fat diet has been associated with alterations in lipid content and composition in skeletal muscle and adipose tissue. Administration of beta3-adrenoceptor (beta3-AR) agonists was recently reported to prevent insulin resistance induced by a high fat diet, such as the cafeteria diet. The objective of the present study was to determine whether a selective beta3-AR agonist (ZD7114) could prevent alterations of the lipid profile of skeletal muscle and adipose tissue lipids induced by a cafeteria diet.

Both free and esterified plant sterols reduce cholesterol absorption and the bioavailability of beta-carotene and alpha-tocopherol in normocholesterolemic humans.

Background: Plant sterols reduce cholesterol absorption, which leads to a decrease in plasma and LDL-cholesterol concentrations. Plant sterols also lower plasma concentrations of carotenoids and alpha-tocopherol, but the mechanism of action is not yet understood.

Objectives: The aims of this clinical study were to determine whether plant sterols affect the bioavailability of beta-carotene and alpha-tocopherol in normocholesterolemic men and to compare the effects of plant sterol esters and plant free sterols on cholesterol absorption.

[2H/H] Isotope ratio analyses of [2H5]cholesterol using high-temperature conversion elemental analyser isotope-ratio mass spectrometry: determination of cholesterol absorption in normocholesterolemic volunteers.

This paper validates the use of high-temperature conversion elemental analyser isotope-ratio mass spectrometry (TC-EA/IRMS) for measuring the [(2)H/H] enrichment of plasma [(2)H(5)]cholesterol. From a molecular point of view, the free cholesterol is initially separated from plasma by thin-layer chromatography (TLC) and then injected onto the TC-EA reactor which converts cholesterol molecules into CO and H(2) gases. The slope of the curve of the experimental mole percent excess (MPE((exp.

Simultaneous determination of deuterated and non-deuterated alpha-tocopherol in human plasma by high-performance liquid chromatography.

Labelled tocopherol is used to evaluate its absorption by biodiscriminating the dietary intake from the endogenous tocopherol pool of subject. A normal-phase high-performance liquid chromatographic method is described for the easy separation and quantification of deuterated (d(6)) and non-deuterated alpha-tocopherol. The alpha-tocopherol isotopomers were extracted from plasma triacylglycerol-rich lipoproteins in hexane, separated by two EC Nucleosil columns in series with a mobile phase of hexane-isopropanol (659.

Hydrolysis of isoflavone glycosides to aglycones by beta-glycosidase does not alter plasma and urine isoflavone pharmacokinetics in postmenopausal women.

We investigated whether the bioavailability of isoflavones could be enhanced by enzymatic hydrolysis of glycosides to aglycones before consumption of a nonfermented soy food. Two drinks were formulated with an enriched isoflavone extract from soy germ (Fujiflavone P10), one of which was hydrolyzed enzymatically with beta-glucosidase to produce aglycones. In a randomized, double-blinded, cross-over study, six European, postmenopausal women consumed each soy drink at a 1-wk interval at a concentration of 1 mg total isoflavones/kg body.

A food-based formulation provides lycopene with the same bioavailability to humans as that from tomato paste.

Lycopene from fresh and unprocessed tomatoes is poorly absorbed by humans. Absorption of lycopene is higher from processed foods such as tomato paste and tomato juice heated in oil. The aim of the present study was to develop a food-grade lycopene formulation that is bioavailable in humans.