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Biomedical subjects

R Suwanik

Publications and source records attributed to R Suwanik.

At least 19 recordsLinked to original sources
PubMed1991

Dose-dependent inhibitory effect of phenolic compounds in foods on nonheme-iron absorption in men.

Nonheme-iron absorption from a typical Southeast Asian meal was studied to examine the effect of a common vegetable, Yod Kratin, which contains a considerable amount of iron-binding phenolic groups. Yod Kratin (leaves of the lead tree) is a very popular vegetable in Thailand. It is consumed at least once a week year round, sometimes every day, together with the main meal. With a common portion size of the vegetable (20 g), iron absorption was reduced by almost 90%. As little as 5 g inhibited iron absorption by 75%. Addition of ascorbic acid partly counteracted inhibition. Adding 100 mg ascorbic acid reduced inhibition of iron absorption from 5 g Yod Kratin by half and the inhibition from 10 g Yod Kratin by a quarter. The study illustrates the marked effect of iron-binding phenolic compounds on iron nutrition and, thus, the importance of acquiring knowledge of the content of such compounds in different foods.

Absorption↗
PubMed1990

Rice and iron absorption in man.

Several studies suggest that iron absorption is low from rice-based meals. Comparisons of the effect of rice starch and wheat starch on iron absorption showed that rice had no effect on absorption. Observed differences in effects on iron absorption between different batches of rice starch could be explained by differences in the phytate content. Phytate is always present in rice grains. The content varies markedly depending on the method of milling. In polished rice, the content of phytate-P varied between 11.5 and 66 mg/100 g rice (data from 45 rice mills in Thailand). The bioavailability of iron in a meal composed of meat, a vegetable and rice varied about threefold (22.1-7.5 per cent) depending on the different phytate content of the rice (4 levels between 30 and 175 mg phytate-P were studied). The inhibitory effect of the phytate in rice was overcome by adding different amounts of an ascorbic acid-rich vegetable (green collard) to the meals.

Biological Availability↗
PubMed1983

Iron absorption in patients with beta-thalassaemia/haemoglobin E disease and the effect of splenectomy.

Intestinal 59Fe absorption was measured in 16 patients with beta-thalassaemia/haemoglobin E disease and in 5 normal controls, using a total-body counting technique. The average iron absorption in the patients was 62% in contrast to 16.5% in the normal controls. 6 of the 9 splenectomized patients had absorption values above 65%, while only 2 of the 7 nonsplenectomized patients had comparably high values.

Adult↗
PubMed1979

The measurement of food iron absorption in man. A methodological study on the measurement of dietary non-haem-Fe absorption when the subjects have a free choice of food items.

1. The present study was considered as a first step to develop a method to measure food iron absorption from realistic common meals prepared and consumed by the subjects themselves in their own homes. The absorption of Fe from the meals was measured by means of the extrinsic-tag method modified to allow for a free choice of food items. 2. The mean Fe intake was 2.79 mg and the mean Fe absorption approximately 0.30 mg. The Fe status of the subjects corresponded to 31.5% absorption from a reference dose solution containing 3 mg elemental Fe as ferrous ascorbate. The variation in food Fe absorption obtained in this field study was found to be of the same magnitude as that obtained in studies performed under more controlled conditions as in the laboratory. 3. The conclusion was drawn that the proposed method could be used in realistic field studies aimed at, for example, explaining or preventing a high prevalence of deficiency. A suffciently long run-in period and a careful instruction of the subjects was considered essential for the design of future field studies.

Adult↗
PubMed1978

Iron absorption from South-East Asian diets and the effect of iron fortification.

The increase in iron absorption was measured when different amounts of ferrous sulphate were added to rice-based South-East Asian meals. The study comprised 158 subjects--118 women and 40 men. Iron fortification of simple meals composed of rice, boiled vegetables, and a curry to a level of 5 mg of iron per meal increased the absorption by about 0.2 to 0.3 mg of iron per meal. The additionof fish to such a meal doubled the absorption increase at a fortification level of 5 mg per meal. This absorption increase was about the same as obtained with composite western-type meals containing fish or meat. The results indicate that iron fortification programs may be effective in countries with rice-based diets provided that there is a suitable vehicle available for fortification.

Absorption↗
PubMed1978

Absorption from iron tablets given with different types of meals.

The absorption of iron from tablets given with 5 types of meals was studied in 153 subjects. The meals were: a hamburger meal with beans and potatoes, a simple breakfast meal, a Latin American meal composed of black beans, rice and maize and two Southeast Asian meals composed of rice, vegetables and spices served with and without fish. The groups were directly compared by relating the absorption from the iron tablets to the absorption from a standardized reference dose of iron given on an empty stomach. The composition of meals with respect to content of meat or fish or the presence of large amounts of phytates seemed to have no influence on the absorption of iron from tablets. The absorption from iron tablets was about 40% higher when they were given with rice meals than when they were given with the other meals studied. The average decrease in absorption by meals was about 50-60% based on a comparison when tablets were given on an empty stomach. When tablets from which the iron was released more slowly were used, the absorption increased by about 30% except when they were given with rice meals, where the absorption was unchanged. The differences among the meals in their effect on the absorption of iron from tablets thus disappeared when the slow-release tablets were given.

Administration, Oral↗