May 17, 2012
When You Heat Natural Plant-Based Foods You Get Acrylamide and Cancer
Nature has a funny way of showing us not to disrupt the perfection of organic produce. Changing the chemical structure of many natural foods, such as exposing them to high heat can promote cancer. Acrylamide is a chemical that naturally forms in certain foods, particularly plant-based foods that are rich in carbohydrates and low in protein, during processing or cooking at high temperatures. We're not only referring to foods like french fries or potato chips, but hundreds of conventional foods that are "ready to eat" in the grocery aisle including cookies, breakfast cereals, popcorn, pizza and even ground coffee.
It's one of the reasons many raw food enthusiasts go raw in the first place. The move to such dietary lifestyles usually stems from the disease promoting chemicals attached to the processed food industry. Acrylamide is just one of many.
It was first confirmed that acrylamide caused cancer in 2002 by the Swedish National Food Authority, however many have long suspected that heating any foods to high temperatures can pose problems to long-term health. The study tested common foods like Folgers instant coffee, Cheerios, and even french fries. The results were so shocking that it sent a tidal wave of concern throughout the scientific community that engulfed the World Health Organization, consumer activists, food manufacturing plants, cancer specialists and nutritionists. Since then, independent studies in the United States, Germany, Norway, Switzerland, and England have confirmed the link between acrylamide consumption and risk of developing cancer.
Acrylamide in not intentionally added to food, but rather forms from naturally occurring components in certain foods when cooked at sufficiently high temperatures. It is formed when frying, baking or grilling carbohydrate-rich foods at temperatures above 120 degrees C.
Health Canada scientists have investigated why some foods have higher levels of acrylamide, for example, baked or fried foods, and have proved that acrylamide is not present in any ingredient of these food items prior to cooking and is not a contaminant inadvertently added at any stage of food preparation. The problem is the end product, not the raw material.
Most acrylamide in food is formed when a natural amino acid called asparagine reacts with certain naturally occurring sugars such as glucose. This only happens when the temperature during cooking is sufficiently high, a temperature which varies depending on the properties of the product and the method of cooking.
The results of Health Canada's work on how acrylamide is formed in food were announced to the international scientific community and to the food industry, and subsequently published in the Journal of Agricultural and Food Chemistry "Acrylamide in Foods: Occurrence, Sources, and Modelling" in 2003.
A study by G. S. Pedersen and colleagues from Maastricht University in the Netherlands analyzed data from 62,573 women aged 55-69 when entering the study in 1986 and found that higher intakes of acrylamide were associated with higher risk of certain types of breast cancer compared to lower intakes.
During the 13-year-follow-up, 2225 cases of breast cancer were identified with hormone receptor status information available in 43 percent of the cases.
"We definitely believe acrylamide is a chemical to be concerned about," says George Alexeeff, deputy director for scientific affairs at the state Office of Environmental Health Hazard Assessment, the office that oversees implementation of Proposition 65. "Our general presumption is that unless there's some other evidence, we assume that if something causes cancer in animals, it causes cancer in humans."
The Environmental Protection Agency considers acrylamide potentially so dangerous that it has fixed the safe level for human consumption at almost zero, with a maximum permissible level in drinking water of 0.12 parts per billion.
By comparison, a 2.4-ounce serving of French fries, a small portion at McDonald's, contains about 401 parts per billion, a small, vending-machine-sized bag of potato chips 466 parts per billion.
Foods Containing Acrylamide
The top 20 foods by average acrylamide intake are as follows:
- French Fries (made in restaurants)
- French Fries (oven baked)
- Potato Chips
- Breakfast Cereals
- Brewed Coffee
- Pies and Cakes
- Soft Bread
- Chile con Carne
- Corn Snacks
- Peanut Butter
- Breaded Chicken
- Soup Mix
Survey Data on Acrylamide in Food
by the U.S. Food And Drug Administration
Collected between 2003, and 2006
Please note: ppb = parts per billion
* THERE HAS BEEN NO
ESTABLISHED LONG-TERM SAFETY LIMIT EVER STUDIED ON ACRYLAMIDE
|Ginger Snap Cookies
|French Market Restaurant Blend Coffee
|Pretzels, hard, salted
|Community Coffee & Chicory New Orleans Blend
|Corn Flakes Cereal
|Baby Food Teething Biscuits
|Prune Juice, bottled
|Baby Food Arrowroot Cookies
|Mariquitas Plantain Chips, 100% Natural
|Shredded Wheat Cereal
|Chocolate Chip Cookies
|Raisin Bran Cereal
|Granola w/ Raisins
|Kashi GOLEAN Crunch
|Popcorn, microwave, butter-flavored
|Taco Bell Mexican Pizza
||0.12 (EPA limit)
The top two food groups listed above - French fries and potato chips - are two of the most damaging foods to human health. Despite the creation of "healthy" varieties of French fries and potato chips like New York Fries - Fried in 100% Non-Hydrogenated Sunflower Oil and Trader Joe's Veggie Chips Potato Snacks, it's important to know that all French fries and potato chips that have been deep-fried in oil are heavily laced with acrylamide and pose a significant threat to one's health.
How To Reduce Your Exposure
"By changing and optimising these factors when producing foods, the acrylamide content of many different types of products can be reduced considerably," says Kit Granby senior scientist at the National Food Institute, Technical University of Denmark.
Based on what is currently known, it is impossible to determine recommended maximum exposure levels or to set daily consumption limits for specific foods containing acrylamide. However, research based on the above foods can give you some idea on which food categories to avoid.
Over the past five years, a research project has identified several ways of reducing acrylamide in foods. The project is a collaboration between the National Food Institute and the Department of Systems Biology at the Technical University of Denmark, the Faculty of Life Sciences at the University of Copenhagen and five Danish food companies.
In addition to the heating temperature, tests carried out during the project also show that factors such as time of processing, pH, water content, water activity and the content of the amino acid asparagine and sugar in the raw ingredients influence the formation of acrylamide. For example, the longer the cooking time and the lower the water content, the higher the acrylamide content in the heat-processed food.
The addition of rosemary to dough prior to baking a portion of wheat buns at 225 degrees C reduced the acrylamide content by up to 60 per cent. Even rosemary in small quantities -- in one per cent of the dough -- was enough to reduce the acrylamide content significantly.
Flavonoids are another type of antioxidant found, among other things, in vegetables, chocolate and tea. Tests also showed that the addition of the flavonoids epicatechin and epigallocatechin from green tea considerably reduced the acrylamide content.
Natasha Longo has a master's degree in nutrition and is a certified fitness and nutritional counselor. She has consulted on public health policy and procurement in Canada, Australia, Spain, Ireland, England and Germany.