The health risks of acrylamide in the human diet are still under investigation. But some facts are already evident. Let’s talk about them.
Acrylamide is a neurotoxic substance and a real danger to the nervous system. For thousands of years, humans have been using heat to cook their food. If heat provides the desired taste, smell, and color, it can also lead to the formation of undesirable substances. One of them is acrylamide.
Discovery of the Health Risks of Acrylamide in Food
Originally, acrylamide was known only for its industrial uses such as the production of plastics, glues, paper, and cosmetics. Accidental exposure of workers to high concentrations of acrylamide has led to the identification of this substance as neurotoxic. In other words, high-dose acrylamide has the power to cause nerve tissue damage. In animals, high doses cause cancer and affect reproduction.
In 2002, researchers at the University of Stockholm in Sweden discovered the presence of acrylamide in certain foodstuffs and since then it has been identified in several foods cooked at very high temperatures.
*** How Does Acrylamide Form in Foods?
The formation of acrylamide in foods is the result of a phenomenon called the Maillard reaction, a chemical reaction between an amino acid – the basic element of proteins – and a simple sugar such as glucose, fructose, or lactose. Heat is needed to initiate the baking reaction, which triggers a series of chemical transformations that result in the “browning” (charring) of food and the formation of different odor and flavor compounds. It is these compounds that give cooked foods their characteristic appearance and flavor. One of the most common illustrations of the Maillard reaction is to heat white bread to turn it into a brown toast. Acrylamide is the result of chemical reactions that occur when carbohydrates in foods are cooked at high temperatures (above 120 ° C or 250 ° F). Foods rich in starch (complex carbohydrate) such as potatoes and flour-based foods contain one type of amino acid, asparagine. At high temperatures, asparagine reacts with the natural sugars of foods to form acrylamide. Foods that are fried, baked, or fired, as well as processed foods, may contain this substance. French fries and chips have the highest levels of acrylamide. Coffee, ready-to-drink, toast, cereals, cookies, popcorn, and crackers are also available.
The formation of acrylamide is only partially understood because the Maillard reaction is one of the most complex chemical reactions occurring in foods. However, the formation and concentration of acrylamide in foods appear to depend on the type of food, the temperature, and the duration of heat exposure. In general, starchy foods (bread, potatoes) cooked at very high temperatures for a long time contain high concentrations of acrylamide.
In addition to cooking time and temperature, research has shown that acrylamide formation is dependent on the content of the asparagine food.
This amino acid has a chemical structure that is comparable to the chemical structure of acrylamide, suggesting that asparagine could be converted to acrylamide during the Maillard reaction.
This substance may appear spontaneously when cooking foods above 120 ° C, for example in fried, baked, or roasted foods. Potato products such as French fries and chips, cookies and crackers, breakfast cereals, baked potatoes, baked goods, or coffee contain acrylamide. Other research has identified this substance in dried fruits, baked vegetables, black olives, and some roasted nuts.
The levels of acrylamide produced depend on:
– the cooking time,
– the amount of asparagine and the reduction of sugars present in cooked foods.
*** Foods That Contain the Highest Levels of Acrylamide
Scientists generally agree that foods that have the highest levels of acrylamide are those that are fried or baked.
– pastries and sweet biscuits
– bread and toast
No trace of acrylamide has yet been detected in foods that have been boiled, poached, or steamed. This can be explained by the maximum temperature of these cooking methods, which does not exceed 100 ° C, and by the absence of a browning reaction.
I – The Health Risks of Acrylamide During Pregnancy
According to a study conducted by the Center for Research in Environmental Epidemiology (CREAL) in Barcelona and published in the online journal Environmental Health Perspectives in October 2012, the consumption by the pregnant woman of foods considered as high levels of acrylamide causes a low weight of birth of the child and a smaller cranial perimeter. The study was conducted from 2006 to 2010 among pregnant women attending 11 maternity units in the cities of Denmark, Greece, Norway, Spain, and England. Mothers completed a food frequency questionnaire either before or at the time of delivery. In total, data were obtained for 1101 mother-infant pairs. The researchers measured acrylamide levels in umbilical cord blood at birth and found that higher acrylamide levels were associated with low birth weight and lower head circumference. The link is confirmed between levels of acrylamide in the umbilical cord blood of babies and maternal consumption of foods considered to be high levels of acrylamide. The Spanish team, in collaboration with other European institutions, warns pregnant women about their diet and, with this risk borne by acrylamide on the development of the baby, implicitly recommends avoiding the fries served, by For example, in fast-food restaurants, it is important to remember the dietary principles that should be favored during pregnancy, ie a diet rich in fruits, vegetables, and proteins.
II – Exposure to Acrylamide Increases the Risk of Cancer
Animal studies have shown that exposure to acrylamide increases the risk of several types of cancer, and the International Agency for Research on Cancer considers acrylamide a probable carcinogen to humans. According to a 1988 study, the data show that acrylamide is capable of inducing genotoxic, carcinogenic, developmental, and reproductive effects in the organisms tested. Acrylamide is a small organic molecule with very high solubility in water. These properties probably facilitate its rapid absorption and distribution throughout the body. After absorption, acrylamide is rapidly metabolized, mainly by conjugation of glutathione, and most of the applied material is excreted within 24 hours. Acrylamide can bind to DNA, which has implications for its genotoxic and carcinogenic potential. A study published in 2007 linked a higher intake of food acrylamide to an increased risk of ovarian and endometrial cancer in postmenopausal women, particularly among non-smokers. It has also been linked to nerve damage and other neurotoxic effects, including neurological problems in workers who handle this substance.
III – The Health Risks of Acrylamide in Food
The World Health Organization says that acrylamide is one of the chemicals that has no reliable identifiable effect level, which means that very low levels are very low risk, but not zero risks. So there are some health risks of Acrylamide in Food even if it exists in small amounts. In 1994, acrylamide was recognized as a carcinogen proven to be an animal and possible for humans by the International Agency for Research on Cancer (IARC). This substance was already known at the time as a danger associated with cigarette smoke and for workers handling this substance. In the latter exposed accidentally, neurological conditions (tremors, decreased coordination of movements,) and skin such as irritation were observed. In 2002, the discovery of the presence of acrylamide in food alerted the international health authorities. If we do not yet know exactly the health risks of Acrylamide for man, scientific studies on rodents have shown that the ingestion of acrylamide in large quantities and over a prolonged period causes the appearance of cancers (thyroid and testicles). in males, and mammary glands, thyroid, central nervous system, oral cavity and uterus in females) and damage to genetic material, as well as to the nervous system.
Many international organizations classify acrylamide as a very harmful substance. It associates:
– Cancers in laboratory animals
– Other effects on health, especially on the reproductive system, development, and the nervous system.
Clinically, the ingestion of acrylamide rapidly induces long-lasting metabolic changes in children and young adults.
IV – The Health Risks of Acrylamide to Children
It is likely that acrylamide affects children in the same way that it affects adults. In children and pregnant women, being in a period of growth and/or gestation, they may certainly be more sensitive to the genotoxic effects of acrylamide. Because of the genotoxicity of acrylamide, children and pregnant women need to pay even more attention to the consumption of products rich in cooked carbohydrates. Acrylamide can cross the placenta and expose it to the fetus. It has also been detected in breast milk. Chips kill hunger, they do not feed. And, in addition, they destroy the slime cells, intended to absorb nutrients from food. A child accustomed to eating potato chips of a customary form weakens or cancels the absorptive capacity of the cellular mucous membranes so that when he ingests spinach, carrots, or tomatoes, he will not take advantage of their nutritional value. Differences in the metabolism of acrylamide. Children consume a larger amount of food relative to their body weight than adults. These are particular foods that make children happy – and rich in acrylamide – such as french fries. Acrylamide is present in a wide range of foods consumed daily, this problem arises for all consumers, but children are the age group most exposed proportionally to their body weight. In most children, fried potato products account for up to half of the total dietary exposure to acrylamide; fresh bread, breakfast cereals, biscuits, crackers, and toast are some of the other sources of exposure. Infant foods are the most important source of exposure for young children.
V – Prevent Formation of Acrylamide
Given the health risks of Acrylamide, international bodies responsible for health topics have recommended reducing the content of this substance in industrial foods.
At the industrial level from 2010, quality control has been established on the levels of acrylamide in these foods during their processing, in order to reduce them, since eliminating them completely is for the moment impossible.
For this, the food industry must improve its food manufacturing technologies that are likely to suffer from these reactions, using as much flour as possible with little asparagine content in its composition or by controlling more precisely the times and temperatures in frying or roasting processes.
*** HEATOX Project Results
To better understand the risks of foods cooked at very high temperatures, the European Commission funded the HEATOX project (Heat-generated Food Toxicants – Identification, Characterization and Risk Minimization).
The goal of HEATOX is to identify, characterize and minimize the risks of harmful compounds produced during cooking. He is particularly interested in acrylamide and made four major conclusions in 2007, following laboratory experiments:
1. Acrylamide in food may be a risk factor for cancer;
2. It is possible to reduce the formation of acrylamide in foods without eliminating it;
3. There are analytical methods for detecting acrylamide levels in foodstuffs;
4. Cooking food can produce other compounds useful for human health.
In 2005, the European Food Safety Authority’s (EFSA) Scientific Panel on Contaminants in the Food Chain confirmed the report’s main conclusions that efforts should be made to minimize exposure to this substance.
EFSA conducted a risk assessment for this substance in food based on about 100 scientific studies and data collected from consumers, NGOs, and the agri-food industry.
The European authority concluded that acrylamide could potentially increase the risk of developing cancer.
Animal studies have shown that acrylamide is genotoxic and carcinogenic and that this compound can damage DNA and cause cancer. In June 2015, EFSA published its first comprehensive assessment of the risks associated with acrylamide in foods. Experts from the Panel on Contaminants in the Food Chain (CONTAM Group) confirmed previous assessments that acrylamide in foods potentially increases the risk of developing cancer for consumers of all age groups. Data from animal studies show that acrylamide and its metabolite, glycidamide, are genotoxic and carcinogenic: they damage DNA and cause cancer. In studies in humans, evidence that dietary exposure to acrylamide causes cancer is currently limited and inconclusive. The scientific advice provided by EFSA will help decision-makers at the national and EU levels to consider possible measures to further reduce consumer exposure to acrylamide in foods. These could include, for example, advice on eating habits and home cooking methods, or controls at the level of commercial food production; however, EFSA has no direct role in decisions on such measures.
*** What Measures Are Being Taken to Reduce the Acrylamide Content of Food?
Food manufacturers have taken steps to reduce the formation of acrylamide in foods such as crispbreads, cookies, and baked goods and crisps by tightening quality controls and modifying recipes and cooking processes. It is important to note, however, that these processes cannot take into account the seasonality factor, which has a significant impact on the precursor content of acrylamide in agricultural raw materials. To take stock of existing knowledge in the agri-food industry, the Confederation of Agri-Food Industries (CIAA) has published a “Toolbox” on acrylamide, which offers manufacturers and consumers a series of measures to reduce the presence of acrylamide in food. The results of the HEATOX research have been taken into account and included whenever possible in this toolbox, which is updated regularly. In France, the National Academy of Pharmacy has advised the moderation and customization of food according to risk factors: diabetes, hyperlipidemia, cancer, cardiovascular and neurodegenerative diseases. Secondly, these new data should motivate and help decision-makers at the national and European levels to study and implement possible measures to further reduce consumer exposure to acrylamide in foods. In particular, on the industrial side.
Researchers are studying the possibility of reducing the presence of acrylamide in foods by blocking the reaction during cooking, through biotechnology and modification of current agricultural techniques.
For example, increasing the level of sulfide in the soil and decreasing the nitrogen content has the effect of reducing the content of some ceramides in acrylamide.
In addition, thanks to genetic engineering, researchers have produced a new potato variety that contains less sugar than ordinary potatoes. The reduction of sugar (glucose) in potatoes should reduce the concentration of acrylamide because this type of sugar is a key element of the Maillard reaction and promotes the formation of acrylamide. Scientists are also targeting genes that in plants are responsible for asparagine formation. Asparagine is another key element required for the formation of acrylamide. Reducing the presence of this compound in plants should have the effect of reducing acrylamide formation during the Maillard reaction.
Research to identify ways to reduce acrylamide formation during the cooking of certain foods continues.
VI – Recommendations to Avoid the Formation of Acrylamide
– Avoid overcooking certain foods (excessive browning). Compliance with cooking instructions on food packaging and good cooking equipment should help to achieve this goal.
– Vary cooking techniques and consider boiling or steaming foods to minimize acrylamide formation. Since products that can contain a lot of acrylamide are also very energetic, it is important to consume them in moderation as part of a balanced diet.
– Monitor the cooking methods by focusing on low temperatures (less than 120 ° C) and cooking with water, steam, or microwave.
– Monitor the cooking or frying oil to prevent it from overheating, avoid over-browning the products when roasting or grilling, and do not consume the most browned areas during cooking.
– Favor a diversified and balanced diet, rich in fruits and vegetables, and moderate in fatty and fried foods.
– Limiting the formation of acrylamide in food is technically possible if all links in the food chain, from producer to consumer are monitored. To give in to the psychosis of acrylamide is useless. Nothing should stop us from eating french fries or cooked food. However, we must still be careful because there are risks for large consumers of fried foods. The secret is to have a varied and balanced diet. This will not only prevent exposure to acrylamide but will also help maintain good health.