Publications by authors named "Machteld van Lieshout"

Prevention of non-communicable diseases through, among other factors, increasing vegetables and fruit (V&F) intake is a cost-effective strategy for risk reduction but requires behavioral change. Such changes in adolescents benefit from their active involvement. The Food Boost Challenge (FBC) was developed using a participatory action research approach to enhance healthy eating behaviors, namely V&F products among adolescents.

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The beneficial effect of fresh tomatoes or processed tomato products on platelet aggregation depends on the presence of bioactive compounds in these products, in sufficient quantities, to produce a relevant physiological effect, when consumed as part of a normal diet. This work is focused on reviewing the development on tomato products bioactive compounds, particularly with reference to its potential biological activity with beneficial effect on the prevention of platelet aggregation.The most relevant studies found show that all bioactive compounds found in Water-soluble tomato concentrate are in tomato fruit and other tomato products, and there is enough evidence of their beneficial effects.

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Data on the vitamin A equivalency of beta-carotene in food are inconsistent. We quantified the vitamin A equivalency (microg) of beta-carotene in two diets using the dual-isotope dilution technique and the oral-faecal balance technique. A diet-controlled, cross-over intervention study was conducted in twenty-four healthy adults.

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Background: Natural antithrombotic agents that influence platelet function are of potential interest for primary prevention of cardiovascular disease. Previous reports showed that tomato extracts inhibit platelet aggregation in vitro, but little is known of the active components, their mode of action, or their efficacy in vivo.

Objective: The objectives of the study were to examine the antiplatelet activity of specific tomato components by in vitro experimentation and to establish their ex vivo efficacy in healthy humans.

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Previously, we have presented a method for quantifying beta-carotene bioavailability based on analysis in serum, following administration of (13)C-labeled beta-carotene. Because stool samples can be collected noninvasively, we have now extended the method to measure the bioavailability based on measurements in feces. An extraction method was developed to enable measurement of concentrations and degree of isotopic enrichment of retinol, retinyl palmitate and carotenoids in feces.

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Vitamin A deficiency is a serious health problem in many developing countries. Provitamin A carotenoids in fruit and vegetables are the major source of vitamin A for a large proportion of the world's population. However, the contribution of plant foods is substantial only when both the consumption and provitamin A content of such food is high and, at the same time, the bioefficacy of the provitamin A is high.

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According to existing recommendations of the Food and Agriculture Organization (FAO)/World Health Organization (WHO), the amount of provitamin A in a mixed diet having the same vitamin A activity as 1 microg of retinol is 6 microg of beta-carotene or 12 microg of other provitamin A carotenoids. The efficiency of this conversion is referred to as bioefficacy. Recently, using data from healthy people in developed countries and based on a two-step process, the U.

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