FAO Nutrition Meetings
Report Series No. 48A
WHO/FOOD ADD/70.39
TOXICOLOGICAL EVALUATION OF SOME
EXTRACTION SOLVENTS AND CERTAIN
OTHER SUBSTANCES
The content of this document is the
result of the deliberations of the Joint
FAO/WHO Expert Committee on Food Additives
which met in Geneva, 24 June -2 July 19701
Food and Agriculture Organization of the United Nations
World Health Organization
1 Fourteenth report of the Joint FAO/WHO Expert Committee on Food
Additives, FAO Nutrition Meetings Report Series in press; Wld Hlth
Org. techn. Rep. Ser., in press.
BROMINATED VEGETABLE OILS
Biological data
Biochemical aspects
Brominated olive oil has been used for radiography in man and
animals without apparent deleterious effects. Bromide ions may be very
slowly released during metabolism of brominated oils (Cortell, 1941;
1956). Feeding of brominated maize oil appears to cause an
accumulation of organically bound bromine in adipose tissues and organ
fat of the rat, pig and man, and this lipid-bound bromine is released
slowly. The exact chemical form in which this organically bound
bromine is present in tissue fats is not yet known (BIBRA, 1970). Rats
fed 0.8% brominated maize oil for 25 weeks accumulated bromine to a
maximum of 10 000 ppm in their body fat after 8 weeks. This level
remained stationary during the remaining 17 weeks. Only 30% of the
bromine disappeared in the following 8 weeks on a normal diet no
change in level having been noted for the first two weeks. Starvation
merely increased the bromine concentration in body fat without
mobilisation of lipid-bound bromine (Gaunt et al., 1968).
Acute toxicity
Five groups of 2-4 rats each were fed brominated olive oil at
levels of 15 000, 10 000, 5 000, 3 000 and 1 000 mg/kg bodyweight per
day. All animals on the three highest doses died by the third or
fourth day, those on 3 000 mg/kg died by the 8th day, but those on the
lowest dose level survived 10 days. No significant pathological
lesions were found at autopsy when compared with controls fed
comparable amounts of olive oil (Cortell, 1941; 1956).
Brominated cottonseed oil was administered orally to groups of 5
male rats in doses of 2 500, 5 000 and 10 000 mg/kg/day. After 4 days
of treatment all rats on the highest dose and 3 out of 5 on the middle
dose had died. The survivors and those on the lowest dose were
lethargic and had decreased body temperatures and respiration rates
(Munro et al., 1969).
Short-term studies
Rat
Three groups of 16 young male and female rats were fed for 8
weeks either 0.5% brominated olive oil, plain olive oil or 0.22%
sodium bromide (equivalent to the total bromine in oil) in their diet.
There were no significant differences from controls regarding growth,
urine analysis, haematology and histological examination of liver and
kidney (Cortell, 1941; 1956).
Five groups of 16 male and 16 female rats were fed for 90 days
brominated maize oil in their diet at 0, 0.05%, 0.2% and 0.8% with
0.8% of plain maize oil as positive control. No significant effects on
growth, haematological indices, renal function tests or serum
chemistry were observed. Maize oil caused a mild degree of fat
deposition randomly distributed within the liver lobules. At the 0.8%
and 0.2% level there was enlargement and fatty infiltration of the
liver and kidneys. Periportal fatty infiltration of the liver was also
seen at the 0.05% level. At the 0.8% level the hepatocytes were
enlarged and foamy. Lipid-bound bromine was found at all levels in
adipose tissue after 13 weeks (Gaunt et al., 1968).
Three groups of 20 male rats were fed semi-purified diet
containing 0, 0.5% or 2.5% of brominated cottonseed oil for 80 days.
Growth and food utilization were impaired at the highest level and
mild anaemia was noted. The liver, heart, kidneys and spleen were
enlarged at the 2.5% level and the heart also at the 0.5% level. All
rats had thyroid hyperplasia, myocarditis, fatty changes in the liver,
arrested testicular development, renal tubular epithelial changes and
reduced liver enzyme activities (Munro et al., 1969).
In another experiment groups of rats were fed 0, 0.02%, 0.1% and
0.5% of brominated cottonseed oil in the diet for 100 days.
Enlargement of the heart appeared at the 0.5% level only, as well as
accumulation of lipid in liver and heart. The activities of the
hepatic drug metabolizing enzymes and isocitric dehydrogenase were
normal but that of glucose 6 -phosphate dehydrogenase was reduced at
the 0.1% and higher level. There was minimal liver pathology but the
hearts of some animals even at the 0.1% level showed degenerative
lesions (Munro et al., 1970).
In another experiment groups of 15 male and female rats were fed
0%, 0 0% or 0.5% brominated cottonseed, corn, olive and sesame oils
for 105 days. Animals at the 0.5% levels showed degenerative heart
lesions with interstitial oedema, swollen cells, hyaline degeneration
and pyknotic nuclei. Lesions progressed to myocytolysis and mild
infiltration with mononuclears. Lipid accumulated in the liver and
microfollicular thyroid hyperplasia was seen. Only 2 animals at the
0.1% level showed mild myocardial changes. The heart weights of all
animals at the 0.5% level were elevated except for brominated olive
oil. All kidney and liver weights were increased at the 0.5% level.
Hearts of animals on brominated cottonseed oil had reduced capacity to
metabolize palmitic acid when fed 400 mg/kg bodyweight per day for 3
days (Munro et al., 1970).
Pigs
Groups of 2 miniature pigs were fed brominated maize oil for 42
days at 100 or 400 mg/kg/day. Tissue analysis showed the accumulation
of lipid-bound bromide in adipose tissue, liver, spleen, adrenals,
brain, kidney and lymph nodes. No organic bromine was detected in
serum or urine. Histology showed no abnormalities apart from very
slight fatty accumulation in the liver (Crampton, 1968).
In another experiment single pigs were given 0, 20, 40, 80 or 160
mg/kg/day brominated vegetable oil for 64 days, followed by 109-178
days on normal diet. Biopsy of subcutaneous adipose tissue showed dose
related accumulation of bromine with a fall in the rate of
accumulation after 20 days. When put on a control diet there was a
very slow decrease in absolute amounts of lipid-bound bromine. All
organs examined contained lipid-bound bromine (Crampton, 1968).
Long-term studies
None available.
Observations in man
Bromine estimation in human adipose tissue fat and other organ
fats from Holland, Germany and U.K. revealed high levels of
lipid-bound bromine only in that country which permitted the use of
brominated vegetable oil as a food additive. High levels of
lipid-bound bromine were found particularly in children up to the age
of 15, the levels in adults being very much lower. Lipid-bound bromine
increased in organ fat in an age-related manner and levels were much
higher in the fat extracted from brain, liver and spleen than from
adipose tissue. Body fat from countries not using brominated vegetable
oils contained only minimal lipid-bound bromine. Apparently no
chemical abnormalities were associated with bromine storage (British
Indust. Biol. Res., Assoc., 1970).
Comments
Brominated vegetable oils were considered at the Ninth FAO/WHO
Expert Committee meeting of Food Additives (FAO/WHO, 1966) but not
evaluated because of lack of suitable data. Attention was then drawn
to the necessity for providing evidence on cumulation and subsequent
release of bromine in body lipids. Recent evidence has demonstrated
accumulation of bromine in the body lipids of the rat, pig and man
(particularly children). Despite the absence of any definite
pathological effects in man, it seems undesirable that lipid-bound
bromine should accumulate in the tissues of man. Progressive cardiac
lesions have been noted in the rat at comparatively high levels of
intake. No long-term studies are available to define a no-effect
level.
Evaluation
The absence of a no-effect level based on long-term studies
precludes the establishment of any formal ADI.
Further work required
Long-term studies using various forms of brominated vegetable
oil, commonly used commercially, with particular emphasis on bromine
storage in tissues and on cardiac pathology.
The significance of bromine deposition in body lipids should be
determined and the possibility investigated of an epidemiological
relationship to cardiac disease in man.
Identification of the brominated derivative(s) accumulated in the
fat of animals and man as well as a study of their toxicological
properties.
REFERENCES
British Industrial Biological Research Association (1970) BIBRA
Information Bulletin (in press)
Cortell, R. (1941) Unpublished report submitted to WHO
Cortell, R. (1956) Assoc. F. D. Off., USA Quart. Bull., 20, 71
Crampton, R.F., Gaunt, I.F. & Gangoli, S.D. (1968) BIBRA Research
Report No.5 Unpublished report submitted to WHO
FAO/WHO (1966) FAO Nutrition Meetings Report Series No.40; Wld Hlth
Org. techn. Rep. Ser., 339
Gaunt, I.F., Grasso, P. & Gangoli, S.D., (1968) BIBRA Research Report
No.6 submitted to WHO
Munro, I.C., Middleton, E.J. & Grice, H.C. (1969) Fd. Cosmet.
Toxicol., 7, 25
Munro, I.C., Middleton, E.J. & Salam, K. (1970) Unpublished report
submitted to WHO