The advent of refrigeration has facilitated the storing of sensitive foods and raw food in general for prolonged periods of time and over great distances. However, some foods remain sensitive to eat in summer when it’s hot outside as even the slightest rise in temperature during storage at any point during the distribution chain or time spent outside a refrigerator can favor bacteria growth and cause foodborne illness. In addition to this, some foods which hold a greater risk of bacteria or parasites contamination like leafy green vegetables remain sensitive to eat in summer.
In particular because not only are they consumed raw, but with the rise in temperatures, people are more inclined to eat lighter and prefer salads to cooked meals, thus increasing the chances of developing some form of food-related illness. Risk categories like small children, the elderly, pregnant women or anyone with chronic illnesses or immunodeficiency would do better to avoid sensitive foods in summer when it’s hot outside if they are not sure they’ve been adequately refrigerated, pasteurized or sufficiently cooked.
Even then, there are risks associated with eating sensitive foods in general, especially in warmer weather and especially if such foods are destined for consumption in raw form. Except for the obvious bad foods to eat in summer (junk food, fast food, sugary fizzy drinks, alcohol and coffee), here are the top foods that carry the potential of causing food-related illness if insufficiently cooked or improperly stored and thus best avoided in summer when it’s hot outside and by more sensitive categories:
1) Raw milk
Has a short shelf life and is likely to spoil very soon, especially if it’s not refrigerated rigorously from the moment it’s produced and throughout the distribution chain, from producer to end consumer. Raw milk begins to sour naturally at room temperature even after as little as a few hours and can be consumed safely in this form, provided it was safe to drink in the first place and is refrigerated after it’s soured (so the souring process is controlled).
However, all raw milk carries risks of food-related illness as it can potentially be a carrier of E. coli, Listeria, Salmonella, Campylobacter and Brucella bacteria and other human pathogens. And higher temperatures in summer encourage the growth of bacteria present in the milk either naturally or as a result of lack of hygiene during collection, processing (packing) and distribution to stores or directly to consumers. This can easily lead to food-related illness, including E. coli gastrointestinal infections, bacterial gastroenteritis and others.
If you do get raw milk, check the label for the production date (which should coincide with the day the milk was collected or the day after that), expiration date and other relevant information from the producer. Make sure the milk has been refrigerated and continues to be kept at low temperatures on the way home. If the milk carton has reached room temperature or has gotten slightly warm by the time you get home, it’s best you discard it. Raw milk should be kept in the refrigerated section at stores or other distributors; don’t get milk that has been left on a shelf at room temperature (either by store employees or shoppers) – by the time it’s returned to the refrigerated section, chances are it’s already spoiled. Also, before you drink raw milk, check smell and taste for indicators of spoilage. Fresh raw milk has a pleasant, fresh smell to it and tastes just a little sweet – there should be no acidic, no acrid and no bitter smell or taste. For children and other categories at risk of food-related illness, it’s best to boil the milk prior to consumption.
2) Certain cheeses
First of all, it’s important to remember that all cheese must be refrigerated to prevent spoilage and food-related illness. But some cheeses in particular spoil extremely fast, in a matter of days or two weeks at most. Raw milk cheese, especially fresh, unripened cheeses (that have not been aged) have the highest potential of spreading food-related illness because they are highly perishable. Examples include paneer, queso blanco, cottage cheese, ricotta, fresh mozzarella etc. Unripened or mildly ripened soft and medium-soft cheeses also spoil fast. Examples include: soft cheeses (Brie, Camembert, Coulommiers) and semi-soft cheeses (Havarti, Muenster).
If it’s summer and temperatures are high, remember to refrigerate your cheese and discard it if it acquires a funny smell or unpleasant, acidic or bitter taste or if you’ve had it for too long (more than 10 days – 2 weeks) and didn’t eat it. Depending on the type, cheese may develop a great variety of bacteria with the potential to cause food-related illness.
3) Leafy salad greens
In summer, when temperatures are high, we all switch to eating lighter meals, usually meat protein and salad vegetables. But lettuce, romaine lettuce, arugula, fresh spinach, endives, radicchio and other leaf vegetables commonly eaten raw as salad greens are all potential carriers of bacteria that cause foodborne illness, especially Escherichia coli, but also intestinal parasites. They are difficult to wash well and often eaten raw and this alone ensures the transmission of bacteria or intestinal parasites fairly easily. Not to mention that in areas where crops are irrigated with untreated or inadequately treated sewage water or greywater, risks of foodborne illness are high. Young children, the elderly, pregnant women and anyone with a chronic disease or immunodeficiency may experience severe food-related illness with complications from ingestion of contaminated leafy greens.
While a great food to eat when it’s hot outside thanks to its high water content (over 91.45 g of water per 100 g of fruit), watermelon is also a source of food-related illness. Watermelon can go bad in the fridge, when left at room temperature and even while still attached to its vine. Once it becomes overripe, it also becomes a serious source of food-related illness, causing diarrhea and severe dehydration as a result, which, in summer and for more sensitive people or those with existing health problems, can prove difficult to manage and predispose to complications.
Cut watermelon can develop slime or mold, although this is often easy to spot and, at this point, nobody will eat it anyway. If the fruit tastes off (tasteless or like fermented fruit) or smells off (usually like fermented fruit or plain spoilt), it’s best to avoid eating it. Good watermelon should have a crisp, juicy pulp, fresh smell and be honey sweet with no unpleasant flavors.
5) Raw fish- sushi, sashimi (raw fish)
Raw fish in general holds many health risks, from bacteria to intestinal parasites. In summer, when temperatures are high, it’s best to avoid eating all forms of raw fish (sashimi) or sushi with raw or undercooked fish or fish eggs. Higher temperatures increase the risk of spoilage and fish spoils extremely fast. And when it’s covered with vinegar, soy sauce and other condiments, it’s harder to tell how fresh it really is. Bacteria from raw fish can also be picked up from cutting boards and other kitchen utensils that haven’t been washed well. It’s important that children, pregnant women and anyone with immunodeficiency avoid raw fish.
6) Raw oysters, mussels and other shellfish
Oysters contain pathogens like E. coli and Vibrio parahaemolyticus bacteria and must undergo a depuration process (they are put in sterilized water for up to 3 days so all the contaminants are removed from the oysters as they process the water). They may also contain stool matter and other contaminants, including heavy metals, depending on how clean the area they were harvested from was. If mussels aren’t fresh, they may develop toxins and become unsafe for consumption even after being cooked. Eating shellfish raw (like is common with oysters) or undercooked (clams, mussels etc.) poses serious health risks especially for children, pregnant women and people with serious illnesses. And since they spoil faster in summer as a result of the higher temperatures, they are best avoided.
7) Undercooked meat: burgers, rare steak etc.
A rare steak, an undercooked burger or ground meat pose serious health risks as they are the perfect medium for bacteria growth. Contamination with E. coli, Listeria or other bacteria or contamination caused by lack of hygiene, especially in summer, can produce serious illness. It’s important to check all meat for signs of spoilage, consider expiration date and cook it well to make it safe for consumption. Also, it’s best to avoid meat with condiments because the addition of flavors may be employed to mask lack of freshness or spoilage.
8) Raw or undercooked eggs
Eggs are primarily carriers of Salmonella bacteria which cause severe food-related illness. It’s important to avoid eating raw eggs in general, not just in summer. For eggs that have been previously washed, refrigeration is mandatory because they spoil faster. Unwashed eggs, although they don’t require refrigeration as they maintain their protective outer layer (cuticle), are also best cooked well as contaminants from the shell can be transferred to one’s plate and cause disease. It’s important to wash your hands after handling eggs and cook them well on both sides, until both the yolk and egg white are not runny anymore. See all eggs varieties (chicken, quail, duck, goose, turkey, ostrich, peahen etc.). And absolutely don’t feed raw or undercooked eggs to children, pregnant women, the elderly or anyone with chronic illnesses or immunodeficiency.
9) Unpasteurized fruit and vegetable juices
We may think this is a healthy option, but unpasteurized fruit and vegetable juice is not that safe for consumption. Fruits and vegetables can be carriers of bacteria such as Escherichia coli, Listeria or intestinal parasites such as tapeworms. See article on Worms and Intestinal Parasites. Not to mention that unpasteurized fruit and vegetable juices spoil really fast in summer when it’s hot outside. The more sensitive the person and the higher the bacterial load, the more serious the illness.
Note: The purpose of this article is not to scare people into avoiding raw food, but to highlight the risks associated with improper storage and insufficient cooking of sensitive foods and foods that are destined to be eaten raw. No food is perfect and a lot of our meal choices come with health risks in certain conditions. The more natural, less processed the food, the better it’s for our health and for the health of other organisms, including bacteria, fungi, parasites, hence the higher risks of food-related illnesses, especially when temperatures sore, as higher temperatures favor microorganisms growth.
And those with underdeveloped immune systems like children, pregnant women, those with heavy medical history files or immune system deficiencies may experience more severe forms of food-related illness as well as stand higher chances of experiencing complications as a result. This makes it all the more important to be aware of the potential risks associated with certain commonly eaten raw or otherwise sensitive foods and take measures to minimize these risks for better health.