Which groups of people are considered high risk for foodborne illnesses? A guide to safe nutrition diet

October 8, 2025 •

5 min read

According to the World Health Organization, hundreds of millions of people fall ill from consuming contaminated food annually. However, certain vulnerable populations are at a much higher risk of suffering severe complications from these infections. Knowing which groups of people are considered high risk for foodborne illnesses? is the first step toward effective prevention and management.

Quick Summary

This article outlines the primary populations most susceptible to serious foodborne illnesses, explaining the physiological and health reasons behind their vulnerability. It details specific pathogens and risky foods to avoid while providing targeted food safety recommendations for these groups. Emphasis is placed on protective measures like proper food handling, cooking, and storage.

Key Points

Older Adults: Weaker immune systems, lower stomach acid, and slower gut motility make individuals aged 65 and older highly susceptible to severe foodborne illness.
Young Children: Underdeveloped immune systems and less stomach acid increase the risk of severe infections and dehydration in children under five.
Pregnant Women: Hormonal changes reduce immunity, increasing susceptibility to pathogens like Listeria and Toxoplasma gondii, which can harm the fetus.
Immunocompromised Individuals: People with conditions like HIV/AIDS, diabetes, cancer, or those on immunosuppressants have a compromised ability to fight infections.
High-Risk Foods: Certain foods like raw or undercooked meat and eggs, unpasteurized products, soft cheeses, and deli meats pose a higher risk of contamination for vulnerable groups.
Safety Measures: Following the four core principles of food safety—Clean, Separate, Cook, and Chill—is essential for minimizing risk, especially when preparing food for high-risk individuals.

Understanding the Increased Risk Factors

While anyone can get food poisoning, certain groups face a significantly elevated risk of severe illness, hospitalization, or even death. This increased vulnerability is primarily due to a weakened or underdeveloped immune system, as well as specific physiological changes that affect how the body combats harmful pathogens. These vulnerable populations include the elderly, young children, pregnant women, and individuals with compromised immune systems due to underlying health conditions or medical treatments.

Older Adults (65 and Older)

As people age, their bodies undergo natural changes that reduce their ability to fight off foodborne pathogens. The immune system becomes less robust, and organs like the liver and kidneys may not function as efficiently at ridding the body of toxins. Furthermore, the stomach may produce less acid, which is a natural defense against many bacteria. Slower gut motility in older adults also gives bacteria more time to multiply and cause illness. Pathogens like Listeria and Salmonella can be particularly dangerous for this group, leading to serious complications and higher hospitalization rates.

Young Children (Under 5)

Children under five years of age are at higher risk because their immune systems are still developing and cannot effectively combat infections. They also produce less protective stomach acid. For young children, foodborne illnesses can quickly lead to severe dehydration from vomiting and diarrhea due to their small body size. Infections with E. coli O157 can be especially perilous for this age group, sometimes leading to a severe kidney complication known as hemolytic uremic syndrome (HUS). Caregivers must be vigilant about food safety behaviors for infants and toddlers.

Pregnant Women

Pregnancy triggers hormonal changes that can temporarily weaken the immune system, making pregnant women more susceptible to infections. Some foodborne pathogens, such as Listeria monocytogenes and Toxoplasma gondii, can cross the placenta and infect the unborn baby, even if the mother has mild or no symptoms. A Listeria infection during pregnancy can lead to devastating outcomes like miscarriage, stillbirth, or severe illness in the newborn. Specific dietary guidelines are crucial for pregnant women to protect both themselves and their baby.

Immunocompromised Individuals

This is a broad category encompassing anyone with a weakened immune system, whether from a medical condition or treatment. This includes people with:

Chronic Diseases: HIV/AIDS, diabetes, liver disease, and kidney disease all impair the immune response. For instance, people on dialysis are significantly more likely to contract Listeria infections.
Cancer Treatment: Chemotherapy and radiation can suppress the immune system by lowering white blood cell counts, leaving patients vulnerable to a wide array of infections.
Organ Transplants: Recipients of organ transplants take immunosuppressant medications to prevent rejection, which leaves their body less able to fight off pathogens.

Safe Food Choices for High-Risk Individuals

To protect vulnerable populations, it is vital to avoid certain high-risk foods and practice careful food handling. The following list highlights foods to avoid and safer alternatives:

Raw or Undercooked Meat, Poultry, and Seafood: This includes sushi, sashimi, rare steaks, and undercooked burgers. Pathogens like Salmonella, E. coli, and Listeria can be present. The safer alternative is to cook all meat, poultry, and seafood to the recommended safe internal temperatures.
Raw or Undercooked Eggs: These can contain Salmonella. Avoid dishes made with raw eggs, such as homemade Caesar dressing, mayonnaise, and cookie dough. Safer options include thoroughly cooked eggs with firm yolks and whites, or using pasteurized eggs/egg products for recipes requiring raw eggs.
Unpasteurized Products: Raw (unpasteurized) milk, cheese, and juices can harbor dangerous bacteria like E. coli and Listeria. Always choose pasteurized products.
Soft Cheeses: Soft cheeses made from unpasteurized milk, such as brie, feta, and queso fresco, are a particular risk for Listeria. Hard cheeses, processed cheeses, and soft cheeses made with pasteurized milk are generally safer.
Deli Meats and Hot Dogs: Unless reheated until steaming hot, these processed meats can contain Listeria. Reheating to 165°F (74°C) is recommended.
Raw Sprouts: Alfalfa, bean, and other raw sprouts can contain harmful bacteria. Thoroughly cooking sprouts eliminates this risk.
Refrigerated Pâtés and Meat Spreads: These can also be a source of Listeria. Canned or shelf-stable versions are a safer alternative.
Honey: Honey can contain Clostridium botulinum spores, which are harmless to most adults but can cause infant botulism in children under one year of age. Honey should not be given to infants.

Comparison of At-Risk Groups and Associated Dangers

To highlight the specific vulnerabilities, here is a comparison table outlining key differences between high-risk groups:


High-Risk Group	Primary Vulnerability	Common Pathogens of Concern	Potential Severe Outcomes
Older Adults (65+)	Weaker immune system, lower stomach acid	Salmonella, Listeria, E. coli	Dehydration, higher hospitalization rates, organ damage
Young Children (<5)	Underdeveloped immune system, low stomach acid	Salmonella, E. coli O157, Campylobacter	Severe dehydration, HUS (kidney failure) from E. coli
Pregnant Women	Altered immune system	Listeria, Toxoplasma gondii	Miscarriage, stillbirth, preterm delivery, severe infant illness
Immunocompromised	Impaired immune system (disease/medication)	Listeria, Salmonella, Campylobacter	Invasive, systemic infections, increased mortality

Essential Food Safety Practices

For everyone, but especially when cooking for high-risk groups, following the four steps to food safety is critical:

Clean: Wash hands, surfaces, and utensils thoroughly and often. Use separate cutting boards for raw meat and produce to prevent cross-contamination.
Separate: Keep raw meat, poultry, seafood, and eggs separate from ready-to-eat foods in your grocery cart, refrigerator, and during preparation.
Cook: Ensure food is cooked to its proper internal temperature to kill harmful germs. Use a food thermometer to be certain, and reheat leftovers until steaming hot.
Chill: Refrigerate perishable foods within two hours (or one hour if temperatures are above 90°F). Do not thaw foods on the counter; use the refrigerator, microwave, or cold water.

Adhering to these guidelines, along with avoiding the high-risk foods mentioned, significantly minimizes the danger of foodborne illness for vulnerable individuals.

Conclusion

While foodborne illness is a threat to everyone, the risk of severe, life-altering, or even fatal consequences is disproportionately higher for older adults, young children, pregnant women, and those with weakened immune systems. This increased vulnerability is tied to the state of their immune system, and specific pathogens like Listeria and E. coli can pose particular dangers. By understanding the risks and diligently practicing food safety principles—such as proper cleaning, preventing cross-contamination, cooking thoroughly, and chilling promptly—we can protect those who need it most. Making informed food choices, like opting for pasteurized products and thoroughly cooked meals, is a fundamental part of providing safe and nutritious diets for these vulnerable populations. For more detailed information, consult resources from authoritative health organizations such as FoodSafety.gov.

Frequently Asked Questions

Older adults are more vulnerable because their immune systems weaken with age, their stomachs produce less acid, and food moves more slowly through their digestive tracts. These factors make it easier for harmful bacteria to cause illness and for infections to become more severe.

For pregnant women, the primary risk is from pathogens like Listeria monocytogenes, which can cross the placenta and cause serious complications for the unborn baby, such as miscarriage, premature birth, or stillbirth. Pregnancy-related immune system changes make them more susceptible.

Infants under one year should not be given honey because it can contain Clostridium botulinum spores. While harmless to older children and adults, these spores can cause infant botulism in babies whose digestive systems are not yet developed enough to fight them.

Several conditions can lead to a weakened immune system, including HIV/AIDS, cancer (especially during chemotherapy), diabetes, and autoimmune diseases. Organ transplant recipients and individuals on certain immunosuppressant medications are also considered high-risk.

High-risk groups should avoid raw or undercooked meat, poultry, seafood, and eggs; unpasteurized milk and soft cheeses; raw sprouts; and refrigerated deli meats and pâtés unless reheated thoroughly.

The four core steps are: Clean (wash hands and surfaces), Separate (avoid cross-contamination), Cook (to safe internal temperatures), and Chill (refrigerate perishable food promptly).

Yes, prepackaged, ready-to-eat salads and fruits carry a risk and should be washed thoroughly, even if prewashed. Homemade salads with freshly washed produce are a safer alternative.