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Many people believe that eating overcooked foods, such as burnt toast, can cause adverse health effects.

In particular, some claim that foods like burnt toast could even be linked to an increased risk of cancer.

While it’s true that what you put on your plate can affect your risk of cancer, many may wonder whether this common claim is actually backed by science.

This article takes a closer look at the evidence to determine whether eating burnt toast can cause cancer.

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Burnt toast contains acrylamide

Acrylamide is a compound commonly used to produce a variety of products, including cosmetics, toiletries, dyes, fabrics, papers, and textiles (1).

However, acrylamide can also form in starchy foods during high-heat cooking methods (2).

This is caused by a chemical reaction between proteins and sugars, giving cooked foods a dark color and distinctive taste (3).

Dietary acrylamide is found in various ingredients, including fried, baked, or roasted foods, including burnt toast (3).

It’s more likely to accumulate when foods are cooked at higher temperatures or for longer periods of time (2).

That means that the more burnt the toast is, the more acrylamide it probably contains.

Acrylamide is a compound that can form in starchy foods, including burnt toast, during high-heat cooking methods.

Acrylamide and cancer

Dietary acrylamide has been linked to several negative health effects, including cancer.

In fact, in 1994 the International Agency for Research on Cancer classified acrylamide as a probable carcinogen in humans (4).

Multiple older animal studies have shown that consuming acrylamide in large amounts may increase the growth of breast and thyroid tumors, as well as contribute to endometrial cancer and testicular mesothelioma (5, 6).

However, studies on the effects of acrylamide on cancer development in humans have turned up mixed results.

For instance, one review of 32 studies concluded that dietary acrylamide is not associated with a higher risk of the most common types of cancer (7).

Another large review observed similar findings, noting no significant association between dietary acrylamide and cancer (8).

On the other hand, a recent study in 4,000 older adults found that increased dietary acrylamide intake was associated with a higher risk of death from cancer in older adults (9).

According to another review, dietary acrylamide could be tied to a higher risk of lymphatic and skin cancer in men, along with a higher risk of esophageal tumors (10).

An additional analysis of 18 studies also showed that acrylamide intake may be linked to a slightly higher risk of ovarian and endometrial cancer, especially among nonsmokers (11).

Still, it’s important to keep in mind that most research is based on observational studies, which determine whether there’s an association between acrylamide intake and cancer but don’t account for other factors that may be involved.

Long-term clinical trials in humans are needed to evaluate whether consuming foods that contain acrylamide could contribute to the development of cancer.

Animal studies suggest that long-term exposure to acrylamide could contribute to cancer growth. However, studies in humans have turned up mixed results, and additional long-term trials are needed.

Should you stop eating burnt toast?

Currently, it’s unclear exactly how acrylamide may affect cancer development and growth in humans.

However, eating burnt toast is unlikely to cause cancer when consumed in moderation as part of a healthy, well-rounded diet.

Therefore, it may not be necessary to eliminate burnt toast from your diet completely.

That said, if you want to reduce your acrylamide intake, you can try toasting it for a shorter amount of time until it reaches a light golden color.

Cutting off pieces that are very dark or burnt can also help limit your acrylamide consumption.

Regarding other foods in your diet, consider decreasing the cooking time or opting for other non-charring cooking methods, such as boiling or steaming, whenever possible (12).

Burnt toast is unlikely to cause cancer when consumed in moderation as part of a healthy diet. Still, several strategies can help you reduce your intake of acrylamide.

The bottom line

Burnt toast contains acrylamide, a compound formed in starchy foods during high-heat cooking methods like roasting, baking, and frying.

Although animal studies have found that consuming high amounts of acrylamide may increase the risk of cancer, research in humans has turned up mixed results.

While consuming burnt toast from time to time as part of a healthy, well-rounded diet is unlikely to cause cancer, several simple steps can help you decrease your intake of acrylamide from toast and other foods.