January 12 Flashcards
Benefits
1) Safer food supply
- antimicrobial : prevent/delay food poisoning (infection, intoxication); - antioxydant : delay the development of off flavours and odors; inhibit the formation of potentially toxic compounds ( e.g. reactive oxygen species [ROS] ); - sulfites : inhibit non-enzymatic browning formation of potential carcinogenic compounds; 2) More nutritious food supply - inhibition/slowing down the destruction of nutritionally important food components (e.g. vitamins, lipids, amino acids/proteins) - replacement of excess calories (lipid replacers, sweeteners) - improved shelf-life and improved food quality (antimicrobials/preservatives) - enhanced nutritional quality of food via the addition of minerals, essential amino acids, essential free fatty acids/lipids, vitamins, proteins, etc. 3) Wider choice of food products - ~20,000 different food items available in a typical grocery store - numerous out-of-season foods available year round - convenience: heat and serve meals; microwavable items/meals; snack foods - diet restriction foods: low calorie; low carbohydrate; low fat; high protein; gluten free; lactose free; diabetic; vegetarian; religion
the food suppply is always reponding to what we want
4) Lower Priced foods
- percent of average income spent on food (in the home) has declined in Canada: 1969 (18.7%)……2009 (10.2%)......2011 (9.7%)......2014 (9.2%) …..2017 ?
pakistan: 1500 yearly income and 42% of that is spent on food
hungarian spend 27% on drinks and tobaco
Risks (Direct)
Direct toxicological effects of additive consumption
Direct toxicological effects of additive consumption
- in many cases (all?) there is insufficient scientific data to prove the absolute safety of a chemical additive (chronic vs. acute toxicity)
very little scientific data exists on the health effects of food additive combination
- very little scientific data exists of the safety of food additive-food component complexes
Food Additive Toxicology
- the study of the adverse effects of chemicals present in foods on living organisms (food toxicology definition )
- intenseity of the biological response is dependent on the dose and purity of the compound being studied
living organisms vary in their sensitivity (i.e. the lowest
dose which elicits a response)
Dose-Response Experiments
a population of organisms (e.g. Salmonella typhimurium [Ames Test], amphibians [frog], Xenopus laevis (used becasu has multiple embryonic stages and very short reproduction cycle) mammalian cell cultures, rats/mice) is subjected to a range of dises of a chemical compound over a defined time period
- a response vs. dose graph is produced
- from this plot NOEL values (no observable effect level or no observed adverse effect levels, NOAEL OR NOAELs) are determined. Defined (for food additives) as “the highest exposure level of the compound resulting in no detectable toxic effect in animals” [determined by subchronic or life-span studies using laboratory animals];
LOAEL:
lowest observable adverse effect level- the lower concentration of the chemical compound/additive where an adver effect was observed
Risks (Direct)
“Toxic Effects”
carcinogen
mutagen
teratogen
carcinogen : an agent directly involved in causing cancer
- mutagen : an agent that alters a cell’s genetic makeup by changing the structure of the hereditary material (i.e. DNA)- afects future generation- ex. cant walk as well, more aggressive
- teratogen : an agent that causes development abnormalities of the fetus or embryo
Delaney Clause (1958)
- “chemicals intended for consumption by humans are not permitted for use if they induce tumors when administered at an concentration to humans or any animals”- at this moment no food would pass this law- uninforcable
Delnaey Paradox
changed it in 1996 - compromise version (July/August 1996) replaced the ‘zero tolerance’ for cancer-causing residues in foods with a “reasonable certainty of no harm” standard
California Proposition 65 (November 1986)
businesses (grocery stores, restaurants, etc.) must provide a clear and reasonable warning if their product, “causes a person to be exposed to a listed carcinogen or reproductive toxicant”
- as naturally occurring carcinogens and reproductive toxicants are ubiquitous in foods; warnings on all foods would be mandatory
again had to change it:
California proposition 65 paradox
- California Health and Welfare Agency had to pass an emergency exemption for naturally occurring toxicants in foods (1 in 100,000 risk)
- Current impact?
4-methylimidazole (added to the list in 2012)
- compound produced during the manufacture of caramel colours/flavours
- Coke (3.8-4.3 g/330 mL [serving]), Pepsi (24-31), Dr. Pepper (22-24), Barq’s Root Beer (9.8-10.1) based on scientific literature a person would need to consume ~1000 servings/day to reach the scientifically established toxicity level (i.e. the doses that lead to cancer in rats)
Based on California Proposition 65 a daily limit of 29 mcg was established ( assumption of 1 in 100,000 cancer risk)-> product reformation
- pepsi (sept. 2015) agreed to pay 385,000 in fines (“not admitting any liability”)
What do we know about the toxicity of food additives?
- there is no direct scientific eveidense linking current additive consumption to toxicity issues in humans
- where animal studies have linked additives with toxicity they have been banned (exception: saccharin in the USA and Europe)
- long term (>20 [>100] years in many cases) toxicity studies on common food additives have been negative
- permitted levels of additives in foods are far below those that produce toxicological effects in animals (many additives show no toxic effects in animals even at extremely high levels; g/kg of body weight)
- existing, and all new additives undergo extensive rigorous scientific testing (animals and human trials- manufacturer independant )
