Acrylamide in food: how much do we need to take heed?

What is acrylamide? 
Acrylamide is a chemical that is formed naturally in a variety of foods when they are cooked or processed at high temperatures (above 120°C), and for longer periods of time. The production of acrylamide usually occurs in high carbohydrate, starchy foods such as bread, potatoes and cereal products however, coffee and roasted almonds are too found to be significant dietary sources of acrylamide.

 Acrylamide is formed when naturally occurring sugars in food and the amino acid asparagine undergo processes such as grilling, frying, baking, roasting, and toasting. Typically, steaming or boiling foods will not result in acrylamide production.
 
Aside from being naturally formed during food processing, acrylamide is an industrial chemical commonly used in construction, papermaking, and water treatment. Acrylamide is also present in food packaging however there is no evidence to suggest this contaminates the packaged food in any way.

What’s the issue? 
In animal studies, acrylamide has been found to be carcinogenic i.e, high exposure was found to cause cancer. In an industrial environment, long-term exposure to the chemical may cause damage to the human nervous system. Whether dietary acrylamide is harmful to humans is currently debated however, several international food safety bodies, including FSANZ, have published guidelines for both consumers and the food industry to reduce exposure.
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In 1994, The International Agency for Research on Cancer (IARC) listed acrylamide as an industrial chemical with a probable human carcinogenic risk.

In 2002, the Swedish National Food Authority first discovered acrylamide in food. Processing methods were determined to be influential, with factors affecting the presence of acrylamide including temperature, high temperature exposure time, presence of amino acid asparagine, and most importantly the concentration of carbohydrates (reducing sugars) in the food. Acrylamide was not found to be present in boiled or unheated foods.

In 2010, the Joint Food and Agriculture Organisation / World Health Organisation Expert Committee on Food Additives (JECFA) deemed acrylamide a human health concern and made recommendations for further research into its effects.
 
The key issue with acrylamide is that it is present in many of our ‘staple foods’. Additionally, the reaction causing acrylamide production is actually one we desire in order to make our food more palatable and pleasing. The combination of reducing sugars i.e., glucose and fructose with amino acids (in this case asparagine) in the presence of heat is known as the ‘Maillard reaction’, and results in the browning of food along with the formation of flavours and aromas. This includes the toasting of bread, the roasting of potatoes, and the baking of cakes until golden. An anticipated aroma and flavour change accompany all of these processes. 

​What is science saying? 
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Acrylamide and cancer
Currently, there is no statistically significant evidence that dietary acrylamide causes, or increases the risk of cancer in humans. This includes pancreatic, breast, prostate, and ovarian cancers. While acrylamide has been found to be carcinogenic in animal models it is important to note that the dose and level of acrylamide exposure is far greater than levels we would be exposed to in food.
 
Neurotoxic effects
To date, the only proven toxic effects of acrylamide on humans are due to industrial occupational exposure. Clinically, this exhibits as nerve damage and those affected report numbness and tingling in limbs. While the average dietary exposure to acrylamide is unlikely to cause neurological damage, the JECFA recommends that the potential for neurotoxicity should not be ignored among those with high dietary exposure. 
 
Effects on reproduction
In animal studies, high and prolonged acrylamide exposure was found to reduce fertility rates, litter sizes, and male sperm count. There is currently no evidence of reproductive toxicity in humans.
 
Effects on the liver
Dietary acrylamide is metabolised by cytochrome P450 in the liver and as such, research has been conducted into the potential for hepatotoxicity. Animal studies report oxidative stress and increased LDL cholesterol in the liver following high and prolonged acrylamide exposure. There is no current evidence to suggest acrylamide is harmful to the liver of humans.  
 
The scientific community encourages further research into the health risks of dietary acrylamide.

So, what does this all mean? 

Determining the extent to which acrylamide poses a health risk is complex without more human specific scientific data. Most of our knowledge surrounding the potential harms is based on evidence from animal studies and as such it’s important to keep in mind that the dose of acrylamide in these studies is often 1000-100,000 times greater than average human exposure.
Until we do know more, it won’t hurt to take a few precautionary steps to reduce our intake of dietary acrylamide.
 
Tips for reducing dietary acrylamide exposure
 
Consumers can take several steps during food storage and preparation to reduce their intake of acrylamide:

• Cook starchy foods like potatoes and bread until golden only. The darker the food, the higher the acrylamide.
• Avoid fried potatoes.  These produce the greatest amounts of acrylamide, followed by roasting and baking. Boiling or microwaving does not produce acrylamide.
• If you are frying or roasting, soaking raw potatoes or blanching beforehand can reduce acrylamide production.
• Don’t store potatoes in the refrigerator. Store in a dark cool place to limit acrylamide formation.
• Follow a balanced and healthy diet with a variety of different foods. Ensuring diet is varied will help manage acrylamide levels.
• Follow cooking instructions on packaged foods. Manufacturers have often adjusted preparation methods to reduce acrylamide formation.

References can be provided on request.

Author

Words by Iydi Willis
Registered Public Health Nutritionist, Health Programs and Community Initiatives at Well College Global.