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.