Toxicological evaluation of some food
    additives including anticaking agents,
    antimicrobials, antioxidants, emulsifiers
    and thickening agents



    WHO FOOD ADDITIVES SERIES NO. 5







    The evaluations contained in this publication
    were prepared by the Joint FAO/WHO Expert
    Committee on Food Additives which met in Geneva,
    25 June - 4 July 19731

    World Health Organization
    Geneva
    1974

              

    1    Seventeenth Report of the Joint FAO/WHO Expert Committee on
    Food Additives, Wld Hlth Org. techn. Rep. Ser., 1974, No. 539;
    FAO Nutrition Meetings Report Series, 1974, No. 53.

    LECITHIN

    Explanation

         This substance has been evaluated for acceptable daily intake by
    the Joint FAO/WHO Expert Committee on Food Additives (see Annex 1,
    Ref. No. 7) in 1963.

         The previously published monograph has been revised and is
    reproduced in its entirety below.

    BIOLOGICAL DATA

    BIOCHEMICAL ASPECTS

         Lecithin is an essential constituent of all cells of the human
    body. The organism is able to synthesize phosphatides and the pathway
    of catabolism of lecithin in the organism is well-known.

         The average diet provides a daily intake of several grams of
    lecithin (approximately 1-5 g).

    TOXICOLOGICAL STUDIES

    Acute toxicity

         No information on the LD50 of lecithin has been found in the
    literature. Rapid infusion into cats of a 1.2% egg-yolk phosphatide
    emulsion containing 5% glucose (1 ml/kg/min) had no effect on the
    respiratory and circulatory systems; rapid infusion of soybean
    phosphatides caused a fall in blood pressure with apnoea (Schuberth &
    Wretlind, 1961).

         Egg-yolk soybean and hydrogenated soybean phosphatides are used
    for the preparation of fat emulsions for parenteral nutrition. The
    newer fat emulsions prepared using well-purified phosphatide
    preparations show a small incidence of side-effects in animals and
    man. Lecithin can be considered a non-toxic substance, even when given
    parenterally.

    OBSERVATIONS IN MAN

         Administration to human subjects of lecithin in daily doses
    varying from 22 to 83 g for two to four months to improve working
    capacity was not accompanied by any untoward reactions (Atzler &
    Lehmann, 1937).

         Lecithin in large amounts (25-40 g per day) given for some months
    will frequently lower the serum cholesterol level. Intolerance to this
    amount limits its use (Merrill, 1959).

         Some crude phosphatides (e.g., cardiac extracts) containing 93%
    lecithin showed pharmacological effects when given parenterally
    (Kunze, 1941). It is not clear if the observed effects were due to
    unidentified by-products.

    Comments:

         Although fewer toxicological studies have been conducted than
    would normally be required for substances used as food additives, it
    is considered that nutritional and clinical experience with lecithin
    is sufficiently extensive to compensate for the incompleteness of the
    experimental data.

         Since many observations have been made in man it is not
    considered necessary to calculate the safe intake level from animal
    experiments.

    EVALUATION

    Estimate of acceptable daily intake for man

         Not limited.*

    REFERENCES

    Atzler, E. & Lehmann, G. (1937) Arbeitsphysiologie, 9, 76

    Kunze, R. (1941) Arzneimittel-Forsch., 1, 88

    Merrill, J. M. (1959) J. Amer. med. Ass., 170, 2202

    Schuberth, O. & Wretlind, A. (1961) Acta chir. scand., Suppl. p. 278

              

    *    See relevant paragraph in the seventeenth report, pages 10-11.

    See Also:
       Toxicological Abbreviations
       LECITHIN (JECFA Evaluation)