Should we worry about getting cancer from eating burnt toast?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Not really. In 2025 Joe Schwarcz published a book titled Better Not Burn Your Toast: The Science of Food and Health. Although there potentially is an acrylamide hazard there is little risk. (I don’t like the taste so I just take a butter knife and scrape off the thin black burnt top layer). A more recent article by Joe Schwarcz at the McGill Office for Science and Society on April 24, 2026 titled Just How Much Should You Worry About Eating That Burnt Toast? discusses it:

 

“Acrylamide forms when the amino acid asparagine and some sugars, mainly glucose, fructose and galactose are heated together to a high temperature. Since asparagine and these sugars are present in many foods and since roasting, baking and frying are common cooking techniques, ingestion of acrylamide is unavoidable. But how much should we worry about its carcinogenicity? 

 

…. In rodents treated with acrylamide, usually in their drinking water, carcinogenic effects begin to be noted when they have consumed about 0.5 mg per kg body weight per day.

 

…. The acrylamide content of many foods has been determined in the lab and human exposure can be calculated from food frequency questionnaires. Typical human exposure turns out to be about 0.3 to 0.6 micrograms per kg body weight per day. This is a thousand times less than the minimal dose that can cause cancer in test animals!” [1 mg = 1000 micrograms]

 

There is another article from Joe Schwarcz in the Montreal Gazette on November 6, 2015 titled The Right Chemistry: No, eating a hotdog is not the same as smoking in which he discusses acrylamide from eating French fries:

 

“Before long scary headlines appear in the lay press: ‘Bacon poses same cancer risk as cigarettes!’ People panic and industry attempts to sooth fears with arguments about poor-quality research, cherry-picked data and calculations about the gross amounts of food that would have to be eaten for the claimed effect to arise: ‘One would have to consume over 150 pounds of French fries every day in order to increase the risk of cancer from acrylamide.’ or, ‘just because we can measure something does not mean the levels are toxic; for farmed salmon, PCB levels were about 3 per cent of the allowable limit of the Canadian Food Inspection Agency, the Food and Drug Administration, the World Health Organization and the European Union.’ ”

 

And there are also web pages titled Acrylamide and Cancer Risk both from the American Cancer Society and the National Cancer Institute.

 

Recent research is discussed in a massive (27-page pdf) article by Burhan Basaran, Burcu Cuvalci, and Guzin Kaban in Food magazine on January 11, 2023 titled Dietary Exposure and Cancer Risk: A Systematic Approach to Human Epidemiological Studies.  Their conclusions are:

 

“Acrylamide, whose presence in foods was shared with the public in 2002 and whose importance has been increasing in our lives since then, still contains many unknowns in terms of its formation mechanism, its level in foods and its effects on health. This uncertainty is a major concern when considering the potential risks of acrylamide. Therefore, more information should be obtained about all the factors that may be caused by dietary acrylamide exposure, and by managing this information, meaningful policies for public health should be produced. The high level of acrylamide in foods such as French fries, bread, biscuits and coffee, which have an important place in our daily life and which we can easily reach and consume throughout life, is an important issue that should be considered for our health. Therefore, many researchers have discussed various aspects of acrylamide, and research is still ongoing today.

In the light of the information obtained in this study, it is quite difficult to say clearly that there is a positive relationship between dietary acrylamide exposure and cancer types. In addition, no direct relationship was found with dietary acrylamide exposure on organs or systems. The lack of a standardized measurement method used by researchers also prevents the studies from being comparable. In this context, it seems that more research is needed to say whether exposure to acrylamide based on nutrition is a risk factor for developing various types of cancer. In order to obtain reliable results in explaining the relationship between dietary acrylamide exposure and cancer, it is very important that future research includes more people and foods. In addition, factors such as physical inactivity, harmful alcohol use, dyslipidemia, obesity and different chronic diseases should be considered as parameters in studies.

Additionally, databases should be established in order to evaluate dietary acrylamide exposure, and the accuracy of the information in the databases should be tested and revised according to the new information obtained. The relationship between dietary acrylamide exposure and cancer risk is unclear. It is necessary to develop new evaluation methods that detect acrylamide and other similar compounds that can lead to clinical pictures, which is the end point of the disease, such as cancer. In this respect, acrylamide and other similar compounds should be included in health policies, and researchers should be supported in terms of information and resources. In addition, legislation on foods with high levels of acrylamide should be developed.”

The image of burnt toast came from Wikimedia Commons.