Cancer is a complex disease resulting from genetic, environmental, and lifestyle factors; no single food item directly causes it. The concern with donuts is that their nutritional profile contributes to a biological environment that increases long-term cancer risk. This risk arises from the metabolic effects of refined ingredients and chemical byproducts of preparation, especially with frequent consumption.
How Refined Sugars Fuel Risk
Donuts are primarily composed of refined carbohydrates, such as white flour and sugar, which have a high glycemic load. Consuming these foods causes a rapid spike in blood glucose levels, prompting the pancreas to release a surge of insulin. This state of chronically elevated insulin, known as hyperinsulinemia, is a significant metabolic factor linked to cancer promotion.
Insulin is a growth-promoting hormone that stimulates cell proliferation. Elevated insulin levels also increase insulin-like growth factors (IGF), which promote cell division and survival. This environment of unchecked cell growth and reduced cell death is a hallmark of cancer development.
Furthermore, the metabolic stress from consistently high sugar intake drives chronic, low-grade inflammation throughout the body. Chronic inflammation and oxidative stress are recognized as conditions that can damage DNA and weaken the body’s defenses against abnormal cells. By repeatedly stimulating these pathways, the consumption of high-sugar, refined foods contributes to a pro-tumorigenic state.
Carcinogens Formed During Frying
The process of deep-frying donuts introduces chemical risks beyond the refined ingredients themselves. The high temperatures required for frying starchy dough lead to the formation of a compound called acrylamide. Acrylamide is classified as a probable human carcinogen based on studies showing it causes cancer in animals.
This chemical forms through a reaction between the sugars and the amino acid asparagine, which are naturally present in the dough, when heated above 120°C (248°F). Since donuts are fried or baked at high heat until they achieve a desirable brown color, they are susceptible to this chemical formation. In the body, acrylamide is converted into glycidamide, which is capable of damaging DNA and causing mutations.
Historically, the fats used for frying also posed a risk, particularly partially hydrogenated oils that contain trans fats. While trans fats are now largely phased out in many regions, the use of unstable oils in high-heat cooking can still generate harmful compounds.
The Context of Consumption
The actual risk from a donut is heavily dependent on the frequency and volume of consumption, placing it within the larger context of one’s entire diet. Donuts are considered high-energy-density foods, meaning they deliver a large number of calories relative to their weight but provide few beneficial nutrients like fiber, vitamins, or minerals.
Regularly eating high-energy-density foods contributes to an excess calorie intake, which often leads to weight gain and the development of obesity. Obesity is a major, independent risk factor for at least 12 different types of cancer. This is because excess fat tissue produces hormones and inflammatory signals that promote tumor growth.
High-energy-density diets have also been linked to increased cancer risk, even in individuals who maintain a normal body weight, suggesting metabolic dysregulation is a factor separate from body mass index. Furthermore, choosing a donut displaces the opportunity to eat protective foods, such as those rich in:
- Fiber
- Antioxidants
- Phytochemicals found in fruits, vegetables, and whole grains