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.

    AGAR

    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

         No information available.

    TOXICOLOGICAL STUDIES

    Acute toxicity

         LD50 values have not been found in the literature.

         Subcutaneous implantation or injection into rats produced a
    foreign-body giant-cell reaction (Tedeschi & Mangiantini, 1956;
    Zbinden & Studer, 1957).

    Short-term studies

    Rat

         Four groups of six rats received diets containing 5%, 10%, 20%
    and 30% of agar respectively for 10 weeks. The group receiving the 10%
    diet gained weight about 20% faster than the controls; the other
    groups gained weight at the same rate as the controls. The rats fed
    diets containing 20% and 30% of agar required significantly more feed
    and water per gram of weight gain than the control group (Nilson &
    Schaller, 1941).

         Six weanling male rats fed a diet containing 25% of agar for four
    weeks showed growth retardation during the third week. The dry weight
    of the cleaned stomach and caecum was found moderately increased.
    Colon and rectum were more than twice as heavy as in the controls
    (Fischer, 1957).

    OBSERVATIONS IN MAN

         For the last 50 years agar has been used as a mild laxative for
    human subjects in daily doses of 4-15 g (Sollmann, 1957).

    Comments:

         Agar is consumed traditionally as food though not as a nutrient.
    The effect on weight gain observed in rats was probably due to the
    lack of utilization of agar, or to its laxative effects, or both. The
    evaluation is based on human data where doses above 5 g only cause a
    laxative effect. Further work is desirable to investigate potential
    storage of macro molecules in the body.

    EVALUATION

    Estimate of acceptable daily intake for man

         Not limited.*

    REFERENCES

    Fischer, J. E. (1957) Amer. J. Physiol., 188, 550

    Nilson, H. W. & Schaller, J. W. (1941) Food Res., 6, 461

    Sollmann, T. (1957) A Manual of Pharmacology, Philadelphia & London,
         Saunders, p. 207

    Tedeschi, G. G. & Mangiantini, M. T. (1956) Arch. Sci. biol., 40, 504

    Zbinden, G. & Studer, A. (1957) Schweiz. Z. allg. Path., 20, 469

              

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

    See Also:
       Toxicological Abbreviations
       AGAR (JECFA Evaluation)