November 2000 - Folate Func Health

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November 2000 - Folate Func Health Powered By Docstoc
					November 2000            Issue 2

From Food to
Functionality and
Optimal Health

                                     Folate F u n c Health
      Introduction                  Erythrocyte Folate Analysis
Welcome to the 2nd                  There is strong interest in the analysis of red cell folate (RCF) as an indicator of folate deficiency risk,
FolateFuncHealth                    because neural tube defects (NTD) can be prevented by additional intake of folic acid prior to
Newsletter. In this issue,          conception, and inverse associations between folate status and vascular
there are articles on optimal       disease and various cancers have also been noted. The analysis
blood extraction for red cell       of RCF depends upon complete hemolysis of erythrocytes,
folate analysis, details of         and it is assumed that complete hemolysis is achieved by
two folate-rich foods (low          10-fold dilution of whole-blood with hypotonic solutions
alcohol-beer and rye bread)         of 1% ascorbic acid. Tony Wright and Paul Finglas, in a
that are being investigated         soon to be published paper in Clinical Chemistry, have
in this project, and on the         investigated this phenomenon.
recent availability of              The conventional method of erythrocyte lysis was
isotopically-labelled folates       modified to include saponin as a known effective
for nutritional studies. In         hemolysing agent at a variety of lysate pH’s using the
addition, we have news              microbiological folate assay. Saponin addition was
about forthcoming meetings          found to increase assayable RCF up to 9-fold,
and conferences involving           depending on lysate pH. Sonication of lysates had no
folates that we will be             effect, and freeze-thawing lysates once did not always
attending. If you would like        guarantee complete hemolysis. Lysates created with pH-
any further information,            unadjusted 1% ascorbic acid (an historical widely used
please contact either               diluent) resulted in significantly lower assayable folate than         Hemoglobin structure showing central            optimal. They concluded that (1) a lysing agent should be
                                                                                                           cavity and potential for trapping folate.

or                                  incorporated into RCF assays to guarantee complete hemolysis; (2) ten-fold dilution of blood with           pH-unadjusted 1% ascorbic acid results in lysates with an acidity (pH 4.0) below the point (pH 4.7) at
or visit our web site at            which hemoglobin can denature irreversibly, and (3) the optimum pH for hemolysates is ca. 5.0.
                                    For further information, contact Tony Wright (
Paul Finglas                        Colour diagram downloaded from
Scientific Coordinator              From Stryer, Biochemistry who adapted the picture from M.F. Perutz, The Hemoglobin Molecule (1964).

Functionality of Rye and Rye Folates                                                                             In addition, the potential of
                                                                                                                 rye bread to increase plasma
                                                                                                                 folate will be evaluated.
Rye is an important folate          name a few.) The health                more refined flours are typically
source for the Finns. It provides   benefits of rye have helped to         used in Sweden and Germany.
                                                                                                                 Rye has been at the centre of
on average as much as                     maintain rye’s popularity        Preliminary results suggest that
                                                                                                                 interest in the Nordic countries
12% of the daily                              as a bread cereal, and       a large proportion of folate in
                                                                                                                 as a potential health food.
folate intake                                    folates in rye is         rye flour is present as formyl
                                                                                                                 This grain, with several special
according to a                                    another topic            forms. This is different from
                                                                                                                 functional properties, is also
recent dietary                                     really worth            typical vegetable folates, which
                                                                                                                 gaining increasing interest
survey. Most                                       exploring in this       are present mostly as
                                                                                                                 elsewhere, as a health food,
Finns love the                                     context.                methylated forms. Process
                                                                                                                 but also as a component of a
taste of rye                                                               stability of formylated folates
                                                                                                                 healthy normal diet. A single
bread, and this                                    Folate content of       might be better than that of
                                                                                                                 nutrient is of course not the
wholegrain                                       rye flour is highly       other reduced folates; this will
                                                                                                                 key to the whole picture - but
product contains a                             dependent of the            be investigated during the
                                                                                                                 what more folates can bring
great variety of other                    extraction rate; the more        course of the project, together
                                                                                                                 into this picture remains to be
health-promoting nutrients as       refined flour the less folates are     with other process effects.
well (including dietary fibre,      to be expected. Fortunately,           Homocysteine lowering
proteins, minerals,                 however, most rye breads in            capacity of rye and rye bread is      For further information,
phytoestrogens, plant sterols,      Finland are baked with                 being investigated in Helsinki in     contact Dr Liisa Vahteristo
phytic acid, polyphenols, just to   wholemeal rye flour. Somewhat          a study with human volunteers.        (
                                                                                                         HPLC Folate
                     Folates in Beer                                                                     Workshop
Cereals contain folates, and      enough data to say how                •   other factors such as        A 2-day workshop on HPLC
since folates are both water      folate content is connected               packaging                    analysis of food folates was
soluble and heat stable it is     to beer style or type. Why                                             organised by Dr Liisa
hardly surprising that            is there so much variation            Processing has been given        Vahteristo and Susanna
folates have been reported        in the folate content of              top place in this list for       Kariluoto (University of
in beer. There are a few          beers, and why are some               good reason. Our                 Helsinki) in April for project
published folate values that      so much better than                   preliminary work has             participants not familiar with
vary widely, with up to 150       others? One obvious                   suggested that as much as        these methods. The purpose
µg/l being reported in some       difference will be raw                60% of folate is lost during     of the workshop was to
beers. Each report has used       materials and since the               processing (Table 1).            familiarise new groups with
different methods of              folate in beer comes from             Therefore, the next phase of     optimised methods for
analysis, making it difficult     the malt, we expected that            this project will involve        sample extraction and clean-
to compare values.                malt content should                        sampling at key points      up, chromatographic
Therefore, the first aim of       be connected to                                 during the brewing     separation and
this project has been to          the folate                                        process to find      quantification of individual
establish both                    content of                                           out where         folates. A working
microbiological (which give       the beer.                                              these losses    document is available from
total folate values) and          In other                                                occur. This    Liisa at
HPLC (which give values for       words,                                                   will be
individual folate vitamers,       beers                                                    carried
mainly 5-MeTHF) methods           with                                                     both in our
of folate analysis, which are     high                                                     pilot plant
optimised for beer and can
be used to give accurate
                                                                                           as well as
                                                                                                         Relevant Future
values for comparing beer
                                  would be
                                                                                                         Meetings and
A range of beers have been
                                  expected to
                                  generally have
                                                                                     Ultimately, we
                                                                                  hope that the
analysed to get an idea of        less folate, whereas                        information from this      The following conferences
what the variation between        those brewed with 100%                part of the project will         include sessions on folates and
folate content in beer types      malt should be higher.                allow us to identify             several project participants will
is. In terms of ‘total folate     When we tested this idea              strategies for optimising the    be making contributions.
content’, we have found           by plotting adjunct usage             folate content of beers.
that this ranged from 17 to       against folate content, we                                             • 3rd FolateFuncHealth
85 µg/l. The beers were           found this was not the                The effect of folates in a         project Meeting,
categorised as either ales,       case. Although the highest            low-alcohol beer on blood          University of Uppsala,
lagers or stouts, but at this     folate containing beer was            levels of homocysteine, an         Sweden, 16-18 February 2001.
stage with a limited              indeed made with 100%                 emerging risk factor for
number of samples, we             malt, other beers did not             cardiovascular disease, will     • Bioavailability 2001,
cannot say which style has        fit into any particular               also be investigated in a          Interlaken, Switzerland,
the higher folate content.        pattern. Clearly other                human study in Norwich.            30 May-1 June, 2001
So how good are these             factors must be important             BRI’s role will be to select       (Contact:bioavailability.2001
folate contents? To put this      and likely possibilities              the beer for this study, ,
is context, two pints (1 litre)   include:                              which has to be chosen             Fax: +41.1.704.57.10).
of our highest scoring beer                                             according to both folate
has the folate content of         •    processing effects               content as well as taste.        • 3rd International
either:                           •    raw materials (barley                                               Conference on Homocysteine
                                       variety; adjunct type)                                              and Metabolism,
                                                                        For further information
•   100 g of broccoli                                                                                      Sorrento, Italy, 4-7 July, 2001
                                  •    folate stability                 please contact Caroline
•   0.5 kg tomatoes                                                                                        Fax: +39.0817.463.116).
                                  •    batch-to-batch                   (c.walker@brewingresearch
•   1.5 litres semi-skimmed                                                                              • 17th International
    milk                                                                                                   Congress of Nutrition,
                                  Vitamin       Malt            Potential      Beer         Recovery       Vienna, 27-31 August, 2001
•   0.25 kg potatoes                            (µg/brew)       in beer        (µg/litre)   (%)
                                  Niacin        884,000         8,500          7,000        82   
As might be expected,
there is wide variation in        Riboflavin    24,300          240            300          125          • ILSI International
the 5-MeTHF content of            Folate        13,100          129            54           42             Symposium on Functional
beer. In a small set of                                                                                    Foods – Scientific and
samples, values have              Table 1: Vitamin content of malt and beer, Pilot brew BRI.               Global Perspectives,
ranged between 8 and 24           Vitamins were determined in the malt and in the beer made from           17-19 October, 2001,
µg/l. Again, we do not have       that malt with a 1 hectolitre brew length.                               Paris, France.
     Highlights from
   Recent Publications                               Isotopically Labelled Folates
   by Project Partners                                  for Nutritional Research
Refereed Papers & Book Chapters:
                                                                    EPROVA AG (part of Merck) has recently announced the
Witthöft, C.M., Forssen, K.,                                        availability of two high-quality 13C-labelled folates carrying a 13C5-
Johannesson, L. &                                                   label at the L-glutamic acid part of the molecule for research
Jagerstad, M. (1999).                                               purposes. The compounds are 13C5-labelled folic acid
Folates – food sources,                                             (Pte[13C5]Glu) and 13C5-labelled (6S)-5-methyltetrahydrofolic acid
analyses, retention and                                             [calcium salt; CH3H4Pte(13C5)Glu-Ca. The latter is the natural (6S)-
bioavailability. Scandinavian                                       isomer of 5-methyltetetrahydrofolic acid, which is also available as
Journal of Nutrition, 43, 138-                                      the unlabelled compound. Both labelled folates have isotopic
46.                                                                 enrichment of >98% and are suitable for nutritional studies. Up
                                                                    to now several isotopically labelled folates have been used by a
Vahteristo, L. & Finglas,                                           few groups to study folate absorption and metabolism in humans
P.M. (2000).                       13C- labelled spinach for folate
                                                                    but these compounds have been synthesised in-house, which is
Chromatographic                    bioavailability studies
                                                                    both time-consuming and laborious. The new compounds will
Determination of Folates. In:      permit new studies in this important area.
Modern Chromatographic
Analysis of Vitamins, 3rd edn.,    For further information on these
A.P. de Leenheer, W.E.             compounds, contact Dr Rudolf Moser
Lambert & J.F. Van Bocxlaer        (
(eds.), Marcel Dekker, Inc:        In the current project, we are
New York, pp.301-323.              conducting two human studies
                                   using isotopically-labelled
Wright, A.J.A., Finglas, P.M.      folates and whole body
& Southon, S. (2000).              models. In Norwich, we
Erythrocycte folate analysis:      are investigating the
addition of saponin when           absorption and short-
lysing whole-blood can             term metabolism of
increase apparent red-cell         folic acid and
folate concentrations greatly,     naturally-occurring
depending markedly on              folates. In Amsterdam,
                                   we are determining                    CALCIUM-L-MEFOLINATE-13C5 [(6S)-5-CH3-H4Pte(13C5)Glu-Ca]
hemolysate pH. Clinical
Chemistry, in press.               whether folate uptake
                                   and cellular retention is impaired in the elderly compared to younger adults. In addition,
Forssen, K., Jagerstad, M.I.,      researchers in Bonn are investigating the relative absorption in humans of 5-methyltetrahydrofolic
Wigertz, K. & Witthöft,            acid [both in its natural (6S-) and racemic forms (6R,S-)] versus folic acid at relevant dietary
C.M. (2000). Folates and           concentrations.
dairy products: a critical         For further information on these studies, contact Dr Caroline Wolfe (Norwich;
update. J. Am. Coll. Nutr., 19, Dr Kees de Meer (Amsterdam; and
(2), 100S-110S.                    Prof Klaus Pietrzik (Bonn;

Marie Curie Training               Talks and Poster Presentations by Project Partners at Conferences
Sites on Micronutrient             and Meetings
Bioavailability at IFR
                                   Ruggeri S., Aguzzi A., Carnovale E. (2000). Folate rich foods: an effective choice for increasing
Research fellowships are           folate intake? In: Micronutrients in the Mediterranean Diet and Health. Cost Action 916, Rome,
available for non-UK PhD           Italy, 23-25 March, in press.
students studying in any EU
country on the influences of       Finglas, P.M. (2000). Development of GC-MS and LC-MS techniques to determine labelled folates
dietary and physiological          in food and biological samples. Workshop on Folate Methodology for Analytic and Metabolic
factors on the availability of     Studies, Experimental Biology 2000, San Diego, USA, 15-18 April, 2000.
essential dietary components       Walker, C., Hilborne, V., Wolfe, C., Wright, A. & Finglas, P.M. (2000). Brewing a better beer –
to their target sites within the   getting more vitamins in your pint! World Brewing Congress, 29 July-2 August, 2000, Orlando, USA.
body. For further information,     Vahteristo, L., Kariluoto, S., Salovaara, H. & Piironen, V. (2000). Variations in folate contents
contact Profs                      of rye varieties and rye fractions – implications for development of high folate cereal products.
Sue Fairweather-tait               European Conference on Nutritional Enhancement of Plant Foods, John Innes Centre, Norwich, UK,
(minerals; sue.fairweather-        6-9 September, 2000.
                                   R. Prinz-Langenohl, Pietrzik, K. et al. (2000). Is 5-Methyltetrahydrofolate superior to folic acid
                                   with regard to short-term bioavailability? Proceedings of the German Nutrition Society, 2, 17.
Sue Southon (organic
micronutrients;                    Pietrzik, K. (2000). The New DRI’s for Folate and Trends in Research. GVF Symposium (Society for          Applied Vitamin Research), Perspektiven für Vitamine, 18 May, Bonn, Germany.
or visit                           Johansson, M., Witthöft, C. & Jagerstad, M. (2000). Bioavailability of folates in cereals and               cereal products. Effect of fortification and processing. National Conference in Food Science, 19-20
vacancies/fellowships              October, Uppsala, Sweden.
                                                    Partner 6                                  Partner 10:
     PROJECT PARTNERS                               Dr Liisa Vahteristo
                                                    Department of Applied Chemistry and
                                                                                               Prof Klaus Pietrzik
                                                                                               Institute of Nutritional Science
                                                    Microbiology                               Department of Pathophysiology of
                                                    Vikki Food Science                         human Nutrition
Partner 1
                                                    Latokartanonkaari 11                       University of Bonn
Paul Finglas (Scientific Coordinator)
                                                    PO Box 27, 00014 University of Helsinki,   Endenicher Allee 11-13 53115 Bonn,
Nutrition Health & Consumer Science Division,
                                                    Finland                                    Germany
Institute of Food Research,Norwich Research Park,
Colney, Norwich, NR4 7UA Norfolk, UK                Fax: +358.9.708.58475                      Fax: +49.228.692055
                                                    E-mail:       E-mail:
Tel: +441603255318
Fax: +44.1603.507723                                Partner 7                                  Partner 11
E-mail:                    Dr Ram Reifen                              Prof Göran Hallmans
                                                    The Hebrew University of Jerusalem         Department of Nutritional Research
Partner 2                                           Institute of Biochemistry, Nutrition and   Umeå University
Dr Kees de Meer                                     Food Sciences                              SE-90187 Umea Sweden
Academic Free University Hospital                   Faculty of Agriculture, Rehovot, Israel    Fax: +46.90.785.2642
Department of Clinical Chemistry                    Fax: +972.936.3208                         E-mail:
Postbag 7057, De Boelaan 1117˚                      E-mail:
1007 MB Amsterdam, The Netherlands                                                             Partner 12
Fax: +31.20.444.0305                                Partner 8                                  Prof Heinz Nau
E-mail:                            Dr Henk van den Berg                       Department of Toxicology
                                                    TNO Nutrition and Food Research            VMH Hannover, Germany
Partner 3                                           Institute                                  Fax: +49.511.856.7680
Dr Caroline Walker                                  PO Box 360 , 3700 AJ Zeist                 E-mail: hnau@lebensmittel.tiho-
Brewing Research International                      The Netherlands                  
Lyttel Hall, Nutfield, Surrey, RH1 4HY, UK          Fax: +
Fax: +44.1737.822747                                                                           Partner 13
                                                    E-mail:        Reg Fletcher
                                                    Dr Jacqueline Castenmiller                 Kelloggs Management Services Europe
Partner 4                                           Department of Human Nutrition &            Ltd
Dr Emilia Carnovale                                 Epidemiology                               Talbot Road, Manchester, M16 0PU UK
Isituto Nazionale della Nutrizione (INN)            Wageninegn Agricultural University         Fax: +44.161.869.2516
Via Ardeatina 546, 00178 Rome, Italy                Postbus 8129 NL-6700 EV Wageningen         E-mail:
Fax: +39.06.5031592                                 The Netherlands
E-mail:                      E-mail:
Prof Pierpaolo Mastroiacovo                         Jacqueline.castenmiller@staff.nutepi.wa
Servizi di Epidemiologia e Clinica dei Difetti
Congeniti                                           Partner 9
Istituto di Clinica Pediatrica                      Prof Gaspar Ros
Universita’ Cattolica Del Sacro Cuore                                                          FolateFuncHealth News
                                                    Food Science and Human Nutrition           Nutrition Health & Consumer Science
Largo Agostino Gemelli, 8                           Campus de Espinardo                        Division, Institute of Food Research, Norwich
00168 Rome, Italy                                   30071 Murcia, Spain                        Research Park, Colney, Norwich, NR4 7UA
Fax: +39.06.3383211                                 Fax: +34.968.364147                        Norfolk, UK
E-mail:                            E-mail:                     ISSN-1472-9700
Partner 5
Prof Margaretha Jagerstad/
Dr Cornelia Witthöft
Department of Food Science
Swedish University of Agricultural Sciences
PO Box 7051, SE 750 07 Uppsala, Sweden
Fax: +39.06.3383211

European Commission:
Torbjörn Ingemansson
European Commission
DGXII.B.1, SDME 8/17
Rue de la Loi 200, B-1044,
Brussels, Belgium
Fax: +

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