Are Leftover Rice and Pasta Bad for Your Health?

A recent news story told the harrowing tale of a young college student who became very ill after eating leftover rice and lo mein noodles. He became so sick, in fact, that he was hospitalized with multiple organ failure and had to have his legs and fingers amputated. Does this mean we should all clear out our cupboards? Should we throw away all rice and pasta products to protect ourselves and our family from a similar fate? The simple answer is “no.” However, there are things we can learn from this tragedy about how to store all leftovers, how to reheat them and when to throw them away.

What Sets Rice and Pasta Apart?

“Microscopic bacteria thrive in certain conditions referenced by the pneumonic FAT TOM: Food, Acidity, Time, Temperature, Oxygen, and Moisture,” says UH food and nutrition specialist, Jessica Jurcak, MS, MPH, RD, LD. “Each type of bacterium has their own specific ideal environment, but in general, bacteria that cause food-borne illnesses thrive in the environments created by cooked foods left sitting out at room temperature. They have a source of food, perfect pH level, an ideal temperature and plenty of oxygen and water to consume, allowing them to multiply quickly,” she adds.

Uncooked rice and pasta can contain spores of the bacterium, Bacillus cereus, which is common and widespread in our environments. Notably, B. cereus can survive even after the food has been properly cooked. If the rice or pasta is left standing at room temperature, like in a pot on the stove, B. cereus spores can quickly multiply and produce a significant amount of toxin. Once refrigerated, the bacteria may go dormant but begin to multiply again when the leftovers are removed and reheated. B. cereus is one of the most common causes of food poisoning in the United States.

The case of the college student is extreme and such a drastic outcome is very rare. Most people who get sick from contaminated food will experience symptoms such as belly pain, cramps, fever, vomiting and/or diarrhea beginning six to twelve hours after eating, as their body’s digestive and immune systems fight the infection. However, the vast majority of people infected with B. cereus will get better within 24 hours. The main health threat to pay attention to is dehydration. Drinking plenty of fluids during the course of the illness is often the only treatment needed, although some severe cases may require antibiotics. Other food borne illnesses can take three to five days for symptoms to fully resolve.

Certain high-risk groups, including the elderly, children, pregnant women and immunosuppressed people, are more likely to get very sick from food-borne illnesses and should seek medical care right away for severe symptoms of food poisoning.

How to Safely Keep Rice and Pasta on the Menu

Both pasta and rice should be cooked according to the package directions and served immediately, while it is still steaming hot. If that isn’t possible or if preparing ahead of time, both should be cooled quickly after cooking and refrigerated within two hours maximum. Place foods in shallow containers in thin layers to help the food cool more quickly. The bottom shelf is usually the coldest area of the fridge, but make sure the containers are properly covered and sealed so nothing from shelves above can fall or drip into the dish. Remember, in the food safety temperature danger zone of 40-140°F, the amount of bacteria can double every 20 minutes so time is definitely of the essence.

When using up rice and pasta leftovers, make sure to heat to 165°F all the way through and eat right away. Do not reheat whole dishes more than once and do not keep either for more than few days even if properly stored and refrigerated. If you notice your cooked rice has an unpleasant smell or there are dry, crunchy grains when reheated, it should not be consumed. Throw it away.

Safety Tips for Storing and Reheating All Leftovers

According to FoodSafety.gov, there are four simple steps we can follow to prevent food contamination and poisoning for all foods: clean, separate, cook and chill. And, in general, all leftovers should be eaten within three to four days - use this Food Keeper resource to look up specific food items. Perishable foods left at room temperature for more than two hours should be discarded and, in very hot weather such as 90°F, even one hour is enough time for bacteria to start multiplying and make you sick. Don’t risk it - toss it.

The UH Department of Clinical Nutrition Services offers a wide range of services designed to help patients manage and prevent disease with dietary strategies personalized to each individual’s needs.