Grace-Anne Bent, Contributor
RESEARCHERS AT the University of the West Indies (UWI) have shone the spotlight on a chemical by-product of fried food and starches cooked at high temperatures that may pose serious health risks.
In April 2002, Swedish researchers sounded the alarm around the world when they concluded that foods, such as potato chips, French fries, bread, rice and processed cereals which are cooked at high temperatures create high levels of a potential cancer-causing agent called acrylamide.
This prompted the UWI's Chemistry Department to take a closer look at the white, odourless chemical to determine the levels of exposure to acrylamide.
Acrylamide is used in the production of another chemical known as polyacrylamide, which has many functions in industry including use in water treatment and the manufacture of fertilisers. It is non-toxic (harmless) to humans.
CANCEROUS TUMOURS
However, acrylamide is quite the opposite. Studies have shown that acrylamide affects the nervous system, even at low levels. Lab animals that have been exposed to large quantities of acrylamide develop cancerous tumours. It is, therefore, a possibility that exposure to acrylamide might also lead to cancer in humans.
When acrylamide is ingested, it is converted to a substance known as glycidamide by enzymes within the body. Glycidamide has the potential to mutate DNA, resulting in genetic mutations.
Acrylamide is soluble in water. The body contains approximately 60 per cent water. This means that acrylamide can move through body fluids.
Research has shown that acrylamide can cross the placenta from mother to child. It can also be passed on from mother to child through breastfeeding. It is, therefore, recommended that pregnant and nursing mothers avoid foods that contain high levels of the chemical.
Acrylamide is quantified as the amount consumed per kilogram of body weight; as a result, children are at a greater risk to acrylamide exposure.
Recent studies have shown that acrylamide is found in foods that are cooked at temperatures above 100 degrees Celsius or 248 degrees Fahrenheit This, therefore, means that foods which are prepared by methods other than boiling have the potential to contain acrylamide.
Higher levels have been found in foods from plant sources than foods from animal sources.
Some of the highest levels have been found in potato products such as French fries and potato chips, but very low levels have been found in meats.
The presence of acrylamide in foods is not attributable to the packaging or storage conditions to which they are exposed, but results from heat-assisted chemical reactions that occur between amino acids (building blocks for proteins) and sugars such as glucose which are nutrients present in our foods.
Of the 20 known amino acids, asparagine is the main contributor to acrylamide formation.
The amount of acrylamide that is formed is directly related to the quantities of precursors (amino acids and sugars) that are present within the foods. Larger amounts of amino acids and sugars lead to more acrylamide.
Foods from plants, especially potatoes ,contain a lot of these precursors while animal produce has smaller amounts of these precursors.
COOKING TIME
The acrylamide content in foods is not only related to high temperatures, but also to cooking time. The longer the cooking time, the more acrylamide is usually formed. Overcooking by five minutes could double the acrylamide content!
Considering the harmful effects that acrylamide can cause, it is important to keep the intake levels at a minimum.
This can be achieved by eating balanced diets, reducing the number of fried, baked, and grilled portions, and by eating a lot of fresh fruits and vegetables.
It is important that foods, ,especially meats, are properly cooked to destroy harmful bacteria.
Since meats and other animal produce do not contain a lot of acrylamide precursors, cooking time or temperature will not significantly affect acrylamide levels.
Acrylamide in foods: Micrograms per serving
Water, 8 oz., EPA limit 0.12
Boiled Potatoes, 4 oz. <3
Old El Paso Taco Shells, 3, 1.1oz. 1
Ore Ida French Fries (uncooked), 3 oz. 5
Ore Ida French Fries (baked), 3 oz. 28
Honey Nut Cheerios, 1 oz. 6
Cheerios, 1 oz. 7
Tostitos Tortilla Chips, 1 oz. 5
Fritos Corn Chips, 1 oz. 11
Pringles Potato Crisps, 1 oz. 25
Wendy's French Fries, Biggie, 5.6 oz. 39
KFC Potato Wedges, Jumbo, 6.2 oz. 52
Burger King French Fries, large, 5.7 oz. 59
McDonald's French Fries, large, 6.2 oz. 82
NOTE
The amount of acrylamide in a large order of fast-food French fries is at least 300 times more than what the U.S. Environmental Protection Agency allows in a glass of water. Acrylamide is sometimes used in water-treatment facilities.
Information taken from the website of the Center For Science in the Public Interest and is based on tests conducted by this U.S.-based organisation.
Acrylamide levels in food products.
Food Type Acrylamide
(µg/kg) (ppb)
Chips, banana 2045
Chips, breadfruit 4686
Chips, potato 2827-3437
French fries 2474- 3491
Potato, boiled Not detected
NOTE
Data from Grace-Anne Bent's analysis of some Jamaica foods.
