Learning Exercise #19
Any chemical “food additive” at high enough doses will eventually cause cancer in
humans or experimental animals
Caffeine is a natural toxicant in coffee, and a food additive in cola drinks; it is not a carcinogen.
10 grams caffeine (100 cups of coffee) per day will not cause cancer; but it will kill you.
Explain the distinction between a food additive that is “toxic”*, and a food additive that
“causes cancer”*; in relation to “safe” levels of the food additive allowed in human food.
*As determined by animal tests
Animal Tests (rats, mice)
Life time: 2 years
Direct food additive: Poison toxin
Dose (ppb)* Effects
50,000 Illness – death 100,000 Immediate death
*Parts per billion
NE – no effect
No effect level – 10,000 ppb
“Safe” tolerance – 100 ppb
Direct food additive that causes cancer
Dose (ppb) Effects