Can eggs with antibiotic traces cause cancer? Here’s the truth

What are nitrofurans?

Nitrofurans are antimicrobial drugs that belong to a single class and were previously used only in poultry and livestock. Prohibitions apply not only in India but also in several other countries due to their extended use in high doses for laboratory animals, which has resulted in carcinogenic potential. Although the detected level of AOZ (a nitrofuran metabolite) in the tested batch of a certain brand of eggs — 0.74 micrograms per kilogram — was below India’s own permissible threshold of 1 microgram per kilogram, the presence of any banned-abroad compound immediately escalated consumer anxiety.

Are nitrofurans actually found in eggs today?

Occasional reports of trace residues have come from small, unregulated farms but these are rare and typically far below safety thresholds. FSSAI conducts regular tests of market samples and most of them are compliant. The residue levels in poultry were determined to be below the harmful level, as reflected by more than 98% of samples obtained in a report from ICAR for 2023.

Which dose is poisonous?

Most studies that linked nitrofurans with cancer were conducted on rats, using doses hundreds of times higher than any residue ever found in food. Consuming eggs with residues that are considered negligible does not mean consuming carcinogenic doses.

Studies in rodents have shown limited evidence of carcinogenicity at very high doses, such as an increase in ovarian tumors in some strains of mice or kidney tumors in male rats, but the relevance of these findings to humans is uncertain. Nitrofurantoin has been widely used for decades to treat urinary tract infections (UTIs) in humans, including during pregnancy when clearly needed, without a proven link to cancer in epidemiological studies.

What is misleading about social media posts?

Viral posts take lab-level toxicity data and apply it to real-world food consumption, creating misinformation. Rare occurrences do not equal cancer risk.

Nitrofurans are banned in food-producing animals because of their potential carcinogenicity with long-term exposure. What worries public health experts is not the occasional egg but the cumulative exposure that can happen when contaminated animal products enter the food chain repeatedly. A common myth circulating online is that “any egg with antibiotics will directly cause cancer.” This is not accurate. Cancer risk is multifactorial and single exposures rarely translate into disease.

Eggs are healthy foods

Rich in nutrients, eggs contain very high protein, vitamin B12, choline and Omega-3s. No scientific or government organisation has suggested egg avoidance as a protective measure.

Who should be cautious?

Only immunocompromised people should follow stricter hygiene rules. Have fully cooked eggs and buy from trusted sources. Just washing eggs does not remove antibiotic traces. These residues are internal, not superficial.

How can consumers protect themselves? 

Buy eggs from certified poultry farms or reputable brands. Choose eggs that are graded by suppliers who comply with FSSAI standards. Cook eggs thoroughly; heat destroys most contaminants anyway.

There is no proof that eggs from regulated markets in India are carcinogenic. Eggs have always been a safe, inexpensive, and excellent source of nutrition. They are especially valuable for patients undergoing cancer treatment who need easy-to-digest protein. The real issue is regulation and enforcement ensuring that farms follow withdrawal periods and that banned antibiotics are not used in the first place.

(Dr Narang is medical and hematology oncologist, CK Birla Hospital, Kathuria is clinical dietician)