Every October, Breast Cancer Awareness Month brings renewed attention to screening, early detection, treatment and survivorship. However, for someone actively undergoing cancer treatment, there is another aspect of health protection that deserves greater attention: Food safety.

A meal that presents relatively little risk to a healthy person may carry more serious consequences for someone whose immune system has been weakened by cancer treatment. This does not mean that every person undergoing treatment needs to live on an extremely restricted diet. It does mean that familiar decisions about leftovers, refrigerated foods, eggs, seafood, fresh produce and eating away from home may need to be approached differently. For patients and their families, understanding why those rules change can make food safety an important part of supportive care.

Why Treatment Can Change Risk

Some cancer treatments, particularly chemotherapy, can weaken the immune system by reducing infection-fighting white blood cells such as neutrophils. This condition, known as neutropenia, can increase the risk of serious infection, although the level of risk varies depending on the treatment and the individual patient.

Treatment can also damage protective tissues in the mouth and gastrointestinal tract, making it easier for microorganisms to enter the body. Food safety is therefore especially important during cancer treatment, not because food becomes inherently more dangerous, but because exposure to foodborne pathogens can have more serious consequences when the body’s normal defences are weakened.

The Same Germ, Different Consequences

People undergoing cancer treatment may face a higher risk of serious foodborne illness because some treatments weaken the immune system.

Listeria monocytogenes is an important example because it can survive and grow even under refrigeration and is often linked to ready-to-eat foods. In one cancer-centre study of 94 listeriosis cases, 90 per cent of affected patients developed bloodstream infection and 36 per cent had central nervous system involvement. The key message is not to fear food, but to take greater care with food safety when immunity is reduced.

Look Again at Ready-to-Eat Foods

Some of the foods that deserve additional attention are not necessarily the foods people traditionally think of as dangerous.

Raw or undercooked meat, poultry, seafood and eggs remain obvious concerns because they may carry organisms such as Salmonella, pathogenic Escherichia coli and other foodborne pathogens. Raw sprouts are another recognised risk because bacteria present on or inside seeds can multiply rapidly under the warm and humid conditions used for sprouting. Research examining sprout-associated outbreaks has shown that organisms such as Salmonella and E. coli O157:H7 can reach very high populations without changing the appearance of the sprouts.

Ready-to-eat refrigerated foods require a slightly different type of thinking. Products such as sliced cooked meats and other chilled ready-to-eat foods may receive no further heat treatment before consumption. Research has repeatedly identified L. monocytogenes as a concern in this category because contamination can occur after processing and the organism can continue to grow during refrigerated storage.

For someone whose medical team has identified significant immunosuppression, the question should therefore be more than: “Is this food expired?” It should also include how the food was prepared, whether it remained refrigerated, how long it has been open, whether contamination could have occurred after cooking and whether another cooking step will occur before it is eaten.

Your Refrigerator Matters More Than You Think

Refrigeration slows the growth of many microorganisms, but it does not sterilise food. A major review of household refrigerator performance found that domestic refrigerators frequently operate above recommended temperatures and that many consumers are unaware of their refrigerator’s actual temperature. The researchers described domestic refrigeration as an important final link in the chilled food chain because inadequate cooling can allow microbial risks to increase between purchase and consumption.

For a household supporting someone undergoing treatment, a refrigerator thermometer is therefore a useful food-safety tool rather than an unnecessary gadget. Refrigerated foods should be stored promptly, raw foods should be separated from foods that will be eaten without further cooking, and containers should be covered and protected from leakage and cross-contamination.

It is also important to remember that cold storage has limits. Listeria monocytogenes is capable of growth under refrigeration, meaning that keeping a food cold does not make indefinite storage safe. Research examining Listeria in ready-to-eat foods has demonstrated that storage conditions after purchase can contribute substantially to risk, particularly among susceptible populations.

Leftovers Deserve More Respect

Leftovers can be convenient during cancer treatment, especially when fatigue, nausea or reduced appetite make preparing fresh meals difficult. However, the way those leftovers are handled matters.

Food should not remain at room temperature for extended periods before refrigeration. Large volumes of cooked food should be divided into smaller or shallower containers so that cooling occurs more efficiently. Food taken from the refrigerator should also be protected from repeated cycles of warming, serving and returning to storage.

Cross-contamination can undo otherwise good cooking practices. A completely cooked meal can become contaminated again through an unwashed cutting board, dirty utensil, contaminated hand, raw meat juices or an inadequately cleaned refrigerator surface.

For caregivers, this is an important mindset shift. The food safety process does not end when the stove is turned off. Cooling, storage, reheating and serving are all part of preparing a safe meal.

A Restrictive ‘Cancer Diet’ Is Not the Answer

Historically, people with neutropenia were often advised to follow highly restrictive diets that excluded foods such as fresh fruits and vegetables in an effort to reduce infection risk. However, research has not shown that these diets consistently prevent infections.

Evidence supports a more practical approach: rather than unnecessarily restricting nutritious foods, cancer patients should focus on reducing exposure to pathogens through safe food choices and good handling practices. Research also suggests that careful food handling may provide better outcomes than highly restrictive dietary rules. Food safety during cancer treatment should protect nutrition, not undermine it.

Eating Away From Home Requires Different Questions

Cancer treatment does not mean that every restaurant meal, family gathering or catered event has to disappear from someone’s life. It does mean that food choices may deserve more scrutiny, particularly during periods when the medical team has identified significant immunosuppression.

Buffets and self-service environments can introduce additional uncertainty because food may spend longer periods being displayed and may be exposed to repeated handling. Raw foods, lightly cooked or served without a final heating step also deserve greater consideration.

The condition of the establishment matters as well. Good hand hygiene, separation of raw and ready-to-eat foods, clean utensils, proper refrigeration and effective temperature control are not cosmetic standards. They are barriers that prevent contamination and microbial growth.

When the consequences of foodborne infection are potentially greater, choosing where and what to eat becomes part of risk management.

Caregivers Are Part of the Food Safety Team

Family members and friends often play an important role in food safety during cancer treatment because they may shop, cook, transport and store meals for the patient. Even a well-prepared meal can become unsafe if it is left unrefrigerated for too long, reheated repeatedly, stored improperly or exposed to cross-contamination.

Caregivers should also remember that foods described as “natural,” “healthy” or “immune boosting” are not automatically safe. Raw juices, undercooked foods and poorly handled produce can still carry harmful microorganisms. The goal is not to create fear around food, but to control preventable risks through safe preparation, storage and handling.

Food Safety Becomes Personal

Breast Cancer Awareness Month is an important time to remember that food safety also has a place in cancer care. Safe food does not treat breast cancer, but it can help reduce avoidable infection risks for patients whose immune systems have been weakened by treatment.

About the Author

Allison Richards is a food safety communicator, certified trainer and the founder of The Food Safety Girl®, a consumer awareness platform promoting food safety in Jamaica and the Caribbean. She is the Caribbean Chapter Director for Women in Food Safety (WIFS) and host of The Big Bite Food Safety Show®. With over 15 years of experience in food safety regulation, she is committed to public education and consumer empowerment. Through public education initiatives, including free community webinars, she continues to create space for learning, dialogue, and practical food safety awareness.

Allison Richards thefoodsafetygirlja@gmail.com .