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Vitamin Research Department, F. Hoffmann-Roche Ltd, CH-4070 Basel, Switzerland
Summary
A diet including 23 portions of fatty fish per week, which corresponds to the intake of 1.25 g EPA (20:5n-3) + DHA (22:6n-3) per day, has been officially recommended on the basis of epidemiological findings showing a beneficial role of these n-3 long-chain PUFA in the prevention of cardiovascular and inflammatory diseases. The parent fatty acid ALA (18:3n-3), found in vegetable oils such as flaxseed or rapeseed oil, is used by the human organism partly as a source of energy, partly as a precursor of the metabolites, but the degree of conversion appears to be unreliable and restricted. More specifically, most studies in humans have shown that whereas a certain, though restricted, conversion of high doses of ALA to EPA occurs, conversion to DHA is severely restrict-ed. The use of ALA labelled with radioisotopes suggested that with a background diet high in saturated fat conversion to long-chain metabolites is ~6% for EPA and 3.8% for DHA. With a diet rich in n-6 PUFA, conversion is reduced by 40 to 50%. It is thus reasonable to observe an n-6/n-3 PUFA ratio not exceeding 46. Restricted conversion to DHA may be critical since evidence has been increasing that this long-chain metabolite has an autonomous function, e.g. in the brain, retina and spermatozoa where it is the most prominent fatty acid. In neonates deficiency is associated with visual impairment, abnormalities in the electroretinogram and delayed cognitive development. In adults the potential role of DHA in neurological function still needs to be investigated in depth. Regarding cardiovascular risk factors DHA has been shown to reduce triglyceride concentrations. These findings indicate that future attention will have to focus on the adequate provision of DHA which can reliably be achieved only with the supply of the preformed long-chain metabolite.
Keywords
Essential fatty acids, Dietary requirements, a-Linolenic acid, Metabolism, Conversion, Eicosapentaenoic acid, Docosahexaenoic acid, Fish oil, Humans, Platelet function, Serum lipoproteins, Triglycerides
International Journal for Vitamin and Nutrition Research, Band 68, 1998, Heft 3, © Verlag Hans Huber, Bern
United States Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Food Safety Research Unit, 600 E. Mermaid Lane, Wyndmoor, PA 19038
Summary
Riboflavin, lumiflavin and lumichrome were produced by light catalysis and gamma irradiation. Their formation under various conditions was determined, and a number of intermediates identified. Fluorescence excitation and emission spectra were determined for the compounds and compared with the absorbency spectra. While lumiflavin predominated in alkali and lumichrome in neutral solutions in the light-catalyzed reaction, all products were produced to some extent under all conditions. Gamma radiation resulted only in the formation of lumichrome, with no observable intermediates.
Keywords
Riboflavin, Light catalysis, Gamma irradiation, Oxidation
International Journal for Vitamin and Nutrition Research, Band 68, 1998, Heft 3, © Verlag Hans Huber AG, Bern
Departamento de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil
Summary
The effect of ascorbic acid (AA) on hepatic d-aminolevulinic acid dehydratase (ALA-D) activity was studied. AA decreased enzyme activity by reducing maximum velocity and tended to increase the Michaelis constant. ALA-D inactivation by AA occurred similarly both in air and argonium atmosphere incubation. DTT reduced considerably the inhibitory effect of AA on ALA-D, but glutathione was ineffective in reversing inactivation. These data indicate that inhibition occurs mainly due to an acceleration of the oxidation rate mediated by the hepatic supernatant utilizing AA in sulfhydryl groups of cysteine residues present at the ALA-D active site. AA probably acts on cysteine from the ALA-D B site since cucumber and radish leaves ALA-D was not inhibited by AA (up to 16 mM). The addition of free radical scavengers to the medium did not alter ALA-D inactivation caused by AA, indicating that active oxygen species formed during AA oxidation were not directly related to -SH oxidation. The chelation of zinc ions from the enzyme by EDTA turned ALA-D more susceptible to the inhibitory effect of AA. This effect seems to involve mainly ZnB, which is known to bind to four cysteines. The present data suggest that AA may participate in the regulation of the heme biosynthesis pathway by promoting a reversible inactivation of ALA-D.
Keywords
Ascorbic Acid, d-Aminolevulinate Dehydratase, Porphobilinogen Synthase, Heme Biosynthesis
International Journal for Vitamin and Nutrition Research, Band 68, 1998, Heft 3, © Verlag Hans Huber AG, Bern
1 Service de Médecine
Gériatrique, Centre Hospitalo-Universitaire Lyon-Sud, 69495
Pierre-Bénite Cedex, France
2 Biostatistiques et Informatique Médicale,
Faculté de Médecine Lyon-Sud, Epidémiologie et
Information Médicale, Centre Hospitalo-Universitaire Lyon-Sud,
69495 Pierre-Bénite Cedex, France
3 Laboratoire de Nutrition, Université Louis Pasteur,
Strasbourg, 67401 Illkirch, France
4 Laboratoire d'Immunologie et de Biologie de
l'Inflammation, Centre Hospitalo-Universitaire Lyon-Sud, 69495
Pierre-Bénite Cedex, France
5 Centre de Recherche en Nutrition Humaine de Lyon,
Faculté de Médecine Laënnec, 69372 Lyon Cedex 08
Summary
The prognostic inflammatory and nutritional index (PINI) is a
simple scoring system of overall health which aggregates two blood
markers of inflammatory (C-reactive protein and a1-acid glycoprotein)
and of nutritional (albumin and transthyretin) states. This study was
undertaken with a view to evaluate, in comparison to currently used
predictive approaches, the potential usefulness of PINI to forecast
hospital mortality and outcome of patients hospitalized in an acute
geriatric unit. 1,066 elderly patients, aged 82.7 ± 6.6 years
and fulfilling inclusion criteria, were enrolled in the study.
Logistic regression analysis and calculation of relative risk (RR)
were carried out for epidemiological data with a cut-off value of 25
for PINI. Immediate mortality (7.9% of admissions) was predicted by
PINI > 25 (RR = 4.34). Only 387 patients (36.3%) could rejoin
their residence location (home or family). A sizeable proportion of
acute patients (55.8%) failed to recover and/or developed diseased
states requiring chronic care management. Incapacity to return home
was predicted by PINI > 25 (RR = 2.04). Hypoalbuminaemia < 30
g/L was not found a predictor of mortality but was associated with
total disability (RR = 9.08). The optimal PINI cut-off value to
predict mortality was calculated at 8.8 using the ROC analytic
approach.
We conclude that the PINI formula is helpful to predict both nearest
lethality and chronic institutionalization. This scoring system
should take a place within the battery of tests used to identify and
to follow up acutely ill elderly patients at risk of major
complications.
Keywords
Elderly persons, Stressful conditions, Albuminaemia, PINI, Prognosis, Mortality
International Journal for Vitamin and Nutrition Research, Band 68, 1998, Heft 3, © Verlag Hans Huber AG, Bern
1 Khonkaen Provincial Health Office,
Thailand
2 Faculty of Tropical Medicine, Mahidol University,
Bangkok, Thailand
3 Khonkaen University, Thailand
4 Deutsche Gesellschaft für Technische
Zusammenarbeit (GTZ), Eschborn, Germany
5 Institute of Social Medicine and Medical
Psychology, Free University Berlin, Germany
Summary
An investigation was undertaken in Northeast Thailand, a country undergoing rapid health transition, to find out whether there is a likelihood that the nutritional and lipid pattern of an adult population in Northeast Thailand is related to coronary heart disease in the same way as in western countries. In a cross-sectional study, the body mass index (BMI) and the waist-hip ratio as well as the important plasma lipids were determined. The nutritional status and the lipid profile of the predominantly middle-aged population is characterised by a generally favourable nutritional status and lipid concentrations, where the distribution, indicated by the medians, of the relevant variables over the total population is concerned. A rather high proportion of individuals was found to be overnourished and to have high triglyceride levels. Individuals with high triglyceride levels run a risk of developing coronary heart disease only when the LDL-HDL fraction is above 5. Only 3% of the total population investigated had a LDL-HDL ratio above that value. Since hypertriglyceridaemia is also linked to the insulin-resistent syndrome, it is concluded that, if the mortality of coronary heart disease increases in future, then this must be accounted probably more to the after-effects of the insulin-resistant syndrome than to the direct effect of an atherogenic lipid pattern. This view is supported by a high prevalence of impaired glucose tolerance (IGT) and non-insulin dependent diabetes mellitus (NIDDM) in the population under survey. Preventive measures in the area should concentrate among others on reducing overnutrition, especially among women, and increasing physical activity and screening for NIDDM.
Keywords
Serum lipids, NIDDM, Epidemiological transition, Thailand
International Journal for Vitamin and Nutrition Research, Band 68, 1998, Heft 3, © Verlag Hans Huber AG, Bern
1 Université De Moncton,
School of Nutrition/Family Studies and Department of
Chemistry/Biochemistry, New Brunswick, Canada E1A 3E9
2 Department of Human Nutrition, TNO Toxicology and
Nutrition Institute, Postbus, NL-3700 AJ Zeist, The Netherlands
Summary
The present study was aimed to assess the psychological status of young healthy women after the administration of a triphasic contraceptive steroid preparation for six complete menstrual cycles. Subjects had never used oral contraceptives (OC) and had neither a familial history of depression nor psychological disturbances. OC-induced psychological disturbances were interpreted for years as evidence of pyridoxine (vitamin B6) deficiency. Other nutritional deficiencies, namely in cobalamin, folate and iron, can disturb the functioning of the central nervous system. In addition, a deficiency of any of these nutrients can lead to several anemia-induced symptoms that are highly susceptible to influence the psychological status. For ample evidence, nutritional status was then evaluated in parallel to psychological testing. Blood iron and vitamin levels of interest were found to be adequate and could not have biaised the response to a psychological test (MMPI). This study showed that a 6-month Triphasil® treatment did not modify significantly the psychological status of subjects. To our knowledge, this is the first psychological study on young never OC-users taking an identical triphasic contraceptive steroid preparation to investigate early psychological side-effects due to OC, at a similar time of the menstrual cycle, when nutritional status was also evaluated.
Keywords
Oral contraceptives, Estrogen, Nutritional status, Psychological disturbances, MMPI
International Journal for Vitamin and Nutrition Research, Band 68,
1998, Heft 3, © Verlag Hans Huber AG, Bern
Biochemistry & Nutrition Discipline Defence Food Research Laboratory, Mysore 570 011, India
Summary
The effect of feeding a fresh garlic or garlic oil-supplemented diet was studied in rats for a period of 23 weeks with or without the treatment of a carcinogen, azoxymethane (AOM), on the modulation of detoxification enzymes and micronuclei formation. The results showed that feeding fresh garlic or garlic oil-supplemented diets tended to reduce hepatic lipid peroxidation, though not to significant levels. Glutathione content was also not altered. The catalase activity in liver of rats fed a fresh garlic-supplemented diet was reduced compared to that of the control diet; however, the activity was not affected by AOM treatment. Ingestion of garlic caused a 40 percent increase in the hepatic glutathione peroxidase activity, whereas carcinogen treatment reduced it. The activitiy of hepatic glutathione-S-transferase was unaffected by the feeding regimen, while it was lowered in the garlic oil diet group treated with AOM. The gamma glutamyl transpeptidase activity was elevated more than sevenfold, in the kidney of rats treated with AOM, while it was reduced almost to half when the AOM-treated rats were fed fresh garlic or garlic oil. Micronuclei formation was increased fourfold, in rats exposed to AOM whereas the increase was reduced to half when AOM-injected groups had either fresh garlic or garlic oil in their diet. From these studies, it is concluded that long-term feeding of garlic, fresh or oil, reduced the toxic effect of AOM in rats.
Keywords
Detoxifying enzymes, Garlic, g-Glutamyl transpeptidase, Micronuclei
International Journal for Vitamin and Nutrition Research, Band 68, 1998, Heft 3, © Verlag Hans Huber AG, Bern