5 Types of Foods That May Increase Cancer Risk – What to Limit in Your Daily Diet

Cancer is one of the leading causes of death worldwide. In addition to genetic and environmental factors, daily dietary habits also play a key role in increasing or reducing the risk of developing cancer. Below are five food groups that have been identified by numerous studies as foods to limit in order to protect your health and reduce cancer risk.

1. Deep-Fried Foods at High Temperatures

Fried foods like French fries, fried chicken, and fritters are often delicious, but cooking at high temperatures, especially deep-frying, can produce harmful compounds such as:

• Acrylamide: Formed when starchy foods (like potatoes) are cooked above 120°C. This is a potential carcinogen, according to the International Agency for Research on Cancer (IARC).

• Polycyclic Aromatic Hydrocarbons (PAHs) and Heterocyclic Amines (HCAs): Found in charred or overcooked meat, these have been linked to colorectal, pancreatic, and stomach cancers.

Particularly dangerous is reusing cooking oil multiple times, which leads to the formation of oxidized compounds and harmful free radicals.

👉 Tip: Replace deep-frying with healthier methods like steaming, boiling, baking with minimal oil, or pan-frying without oil.

2. Smoked and Processed Meats

Smoked meats, sausages, and preserved foods often contain preservatives and additives, especially nitrates/nitrites.

In the stomach, nitrites can combine with stomach acid to form nitrosamines, which are well-established carcinogens, particularly associated with colorectal cancer.

Moreover, the smoking process may introduce benzopyrene – a powerful carcinogen found in wood or charcoal smoke.

👉 Tip: Limit consumption of processed meats. Choose fresh, homemade options whenever possible.

3. Improperly Pickled or Fermented Foods

Pickled vegetables like fermented cucumbers, cabbage, or kimchi can be healthy if made properly. However, when:

• Fermented too quickly (e.g., under 3 days),

• Prepared under unhygienic conditions, or

• Stored for too long,

...these foods can accumulate high levels of nitrites, which may form nitrosamines in the stomach, increasing the risk of stomach cancer.

Excessively salty pickled foods can also raise blood pressure and put strain on the cardiovascular system.

👉 Tip: Only eat well-fermented and cleanly prepared pickles. Discard anything with mold, unusual smells, or excessive sourness.

4. Moldy or Spoiled Foods

Foods such as rice, peanuts, corn, cashews, or bread that are moldy may contain aflatoxins – among the most potent liver carcinogens known, according to the World Health Organization (WHO).

Aflatoxins are produced by the fungus Aspergillus flavus, especially in hot and humid climates like in many parts of Southeast Asia.

👉 Tip: Never consume any part of a moldy food item, even if only partially affected. Store dry foods in cool, dry, airtight containers.

5. Leftover Food Stored Improperly

Keeping leftovers is a common habit. However, if food is:

• Not refrigerated properly, or

• Stored for too long (more than 2–3 days),

…it can become contaminated with bacteria, fungi, or nitrites that may be harmful.

Although there is no strong evidence showing that leftovers stored for more than 24 hours directly cause cancer, poor storage can lead to foodborne illness and increase the risk of long-term health problems.

👉 Tip: Consume leftovers within 1–3 days and reheat thoroughly before eating.

How to Reduce Cancer Risk Through Diet and Lifestyle

✅ Maintain a balanced diet:

• Eat plenty of fresh vegetables, fruits, legumes, and whole grains.

• Aim for 30–40 grams of fiber per day, which helps move waste through the digestive tract and reduces cancer-causing substances in the gut.

• Limit processed foods and items high in sugar, salt, and fat.

✅ Exercise regularly:

• Engage in at least 30 minutes of physical activity daily such as brisk walking, cycling, or stair climbing.

• Helps maintain a healthy weight and reduces the risk of cancers like breast, colon, prostate, and lung.

✅ Avoid tobacco and alcohol:

• Tobacco contains more than 60 known carcinogens and is the main cause of lung and throat cancer.

• Alcohol metabolizes into acetaldehyde, a carcinogen linked to liver, mouth, and esophageal cancer.

Conclusion

No single food causes cancer immediately, but long-term habits involving unhealthy food choices and poor lifestyle behaviors can significantly increase your risk.
To protect your health:

• Avoid or limit the five high-risk food types listed above,

• Adopt a nutrient-rich and balanced diet,

• Stay physically active and avoid harmful substances,

…so your body can stay strong and resilient against disease, including cancer.