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Hans Verhagen

Publications and source records attributed to Hans Verhagen.

6 recordsLinked to original sources
PubMed2006

Effectiveness of customary use of phytosterol/-stanol enriched margarines on blood cholesterol lowering.

Postlaunch monitoring of functional foods can encompass monitoring of effectiveness under conditions of customary use. To this end, the effectiveness of phytosterol/-stanol enriched margarine consumption in free-living conditions was investigated with data from the Dutch "Doetinchem cohort study". In total, 4,505 subjects (aged 26-70 years) were examined in 1994-1998 and re-examined during 1999-2003. A general and a food frequency questionnaire and non-fasting blood samples for total and HDL cholesterol determination were obtained. Subjects were stratified into phytosterol/-stanol enriched margarine users (n = 84) and non-users (n = 4,421) based on the re-examination data, as these margarines were available on the Dutch market from 1999 onwards. Mean spontaneous daily use (g +/- SD) of phytosterol-containing margarine (n = 71) was 15 +/- 8 and of phytostanol-containing margarine (n = 13) 9+/-6. After five years, total blood cholesterol had increased with 0.26 mmol/l in non-users while it had not significantly changed in users. The difference in total blood cholesterol change in users versus non-users was -0.30 mmol/l (p < 0.001). The beneficial effect of the phytosterol/-stanol enriched margarine, used under customary conditions can be characterized as a stabilization of cholesterol levels. This is the first report finding a modest beneficial effect on blood cholesterol level under customary conditions thereby partly confirming findings from clinical trials.

Adult↗
PubMed2004

Assessment of the efficacy of functional food ingredients-introducing the concept "kinetics of biomarkers".

Functional foods are "foods and beverages with claimed health benefits based on scientific evidence". Health claims need to be substantiated scientifically. The future of functional foods will heavily rely on proven efficacy in well-controlled intervention studies with human volunteers. In order to have the maximum output of human trials, improvements are needed with respect to study design and optimization of study protocols. Efficacy at realistic intake levels needs to be established in studies with humans via the use of suitable biomarkers, unless the endpoint can be measured directly. The human body is able to deal with chemical entities irrespective of their origin, and the pharmaceutical terms "absorption, distribution, metabolism and excretion" have their equivalent when biomarkers are concerned. Whereas only "diurnal variation" or "circadian rhythm" is sometimes considered, little attention is paid to "kinetics of biomarkers". "Kinetics of biomarkers" comprises "formation, distribution, metabolism and excretion". However, this is at present neither an established science nor common practice in nutrition research on functional foods. As a consequence, sampling times and matrices, for example, are chosen on the basis of historical practice and convenience (for volunteers and scientists) but not on the basis of in depth insight. The concept of kinetics of biomarkers is illustrated by a variety of readily comprehensible examples, such as malaria, cholesterol, polyphenols, glutathione-S-transferase alpha, F2-isoprostanes, interleukin-6, and plasma triacylglycerides.

Biomarkers↗
PubMed2003

PASSCLAIM - Synthesis and review of existing processes.

Several approaches to the use of health claims on foods have been made around the world, and the common theme is that any health claim will require scientific validation and substantiation. There is also broad consensus that any regulatory framework should protect the consumer, promote fair trade and encourage innovation in the food industry.This paper is based on a critical evaluation of existing international approaches to the scientific substantiation of health claims, with a view to identifying common new ideas, definitions, best practice and a methodology to underpin current and future developments. There is a clear need to have uniform understanding, terminology and description of types of nutrition and health claims. Two broad categories were defined: Nutrition Claims, i. e. what the product contains, and Health Claims, i. e. relating to health, well-being and/or performance, including well-established nutrient function claims, enhanced function claims and disease risk reduction claims. Such health claims relate to what the food or food components does or do. The categories of health claims are closely and progressively related and are, in practice, part of a continuum. Provision is also made for "generic" or well-established, generally accepted claims and for "innovative" or "product-specific" claims. Special attention was paid to reflect the health-promoting properties of a food or food component in such a way as to facilitate the making of risk reduction claims outside the medical scope of the term prevention. The paper sets out basic principles and guidelines for communication of health claims and principles of nutritional safety. The main body of the work examines the process for the assessment of scientific support for health claims on food and emphasises an evidence-based approach consisting of: Identification of all relevant studies exploring the collection of evidence, data searches, the nature of the scientific evidence, sources of scientific data (including human intervention studies, human observational studies, animal studies and in vitro studies, and the use of biomarkers in human studies. Evaluation of the quality of individual studies to ensure good experimental design and interpretation. Interpretation of the totality of evidence to apply scientific judgement to interpret the weight of evidence as a whole. Assessment of significant scientific agreement on a case-by-case basis to agree within the relevant scientific community that an association between a food or a food component and a health benefit is valid. Annexes include an international comparison of regulatory approaches to health claims, suggestions for the documentation and presentation of evidence, and a procedure for reviewing the evidence.

Canada↗
PubMedDate not supplied

Biomarkers.

Explore the source record for details and available documents.

Amino Acids↗
PubMedDate not supplied

Synthesis of isothiocyanate-derived mercapturic acids.

Twelve mercapturic acids derived from saturated and unsaturated aliphatic and aromatic isothiocyanates were synthesised, by adding isothiocyanate to a solution of N-acetyl-L-cysteine and sodium bicarbonate, in a typical yield of 77%. Isothiocyanates were synthesised first by adding the corresponding alkyl bromide to phthalimide potassium salt. The obtained N-alkyl-phthalimide was hydrazinolysed yielding the alkyl amine, which subsequently was reacted with thiophosgene yielding the isothiocyanate with an overall yield of 16%. Mercapturic acids in urine can serve as a biomarker of intake to determine the health promoting potential of isothiocyanates present in cruciferous vegetables.

Acetylcysteine↗