According to the Centers for Disease Control and Prevention (CDC), Listeria infection is caused by the bacteria Listeria monocytogenes which is one of the leading causes of foodborne illnesses within the U.S. Listeria is found in soil, water and some animals and is unique because of its ability to grow in cold temperatures.

Listeria can be found in any product that is not cooked immediately before consumption but is commonly associated with raw milk, products made from raw milk, and some processed foods, Dr. Nwadike said. The outbreak in Europe involved frozen vegetables. Listeria bacteria is killed through pasteurization and proper cooking methods.

Listeriosis, which is the illness caused by a Listeria bacteria infection, can affect anyone but certain groups of people are at a much higher risk. Dr. Nwadike said pregnant women, young children, those who are over the age of 65 and those who have a weakened immune system should be especially careful.

Symptoms of listeriosis can vary but often include flu-like symptoms, such as fatigue and muscle aches. Symptoms can occur the same day as eating contaminated food but usually take one to four weeks to show. Listeriosis is diagnosed using a bacterial culture from a body tissue or fluid, such as a blood sample, and once diagnosed is treated with antibiotics.

To avoid contracting Listeria follow these steps:

• Chill food to the correct temperature. Check your refrigerator’s and freezer’s temperature with a thermometer. Your refrigerator should be less than 40°F and your freezer less than 0°F.
• Use ready-to-eat foods by the “use by” date.
• Clean your refrigerator regularly with hot water and a mild soap.
• Follow proper food safety protocols including rinsing raw produce thoroughly.
• Closely follow cooking directions on packages and do not eat food raw that is intended to be cooked before consumption.
• Avoid higher-risk foods such as unpasteurized milk and raw sprouts. This is particularly important for those at higher risk for listeriosis.

Those at a higher risk for listeriosis should take extra precautions such as heating hot dogs and deli meats before consuming.

Canada and the United States have extensive regulations in place to reduce foodborne illnesses. Dr. Nwadike mentioned that food processors rely on strict sanitation standards to ensure the products they produce are free from contamination. Federal, state and local governments investigate foodborne illnesses to stop outbreaks.

Listeria is a type of bacteria that can cause foodborne illness. To avoid contracting listeriosis, follow proper food safety protocols and use caution when consuming certain foods.

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1. Onions contain flavonoids, unique compounds found in plants that also have health benefits. “They contain mainly the bioactive compound quercetin, which has been implemented as an antioxidant, anticancer and anti-inflammatory compound,” said Dr. Ruth McDonald, Chair and Professor of the Department of Food Science & Human Nutrition, Iowa State University.
2. Besides flavor, onions do not contribute much to the diet. “Onions are not very nutrient dense,” Dr. McDonald explained. One cup of chopped onion contains 234 mg of potassium, compared to about 537 mg in a banana. (One cup is a lot of onions!)
3. Onions contain sulfur compounds. That’s why your eyes water when you chop them and why the odor lingers on your breath.
4. These sulfur compounds led to onions being used for medical purposes in many cultures, such as treating wounds. However, the effect was minimal. “There is folklore that onions are antibacterial because of the presence of sulfur-containing compounds. But they are unlikely to have sufficient potency to treat infections,” Dr. McDonald said.
5. This belief in the antibacterial effect led to the practice of placing a cut onion by the bedside to prevent illness, with the idea that the onion would soak up germs. “Absorbing bacteria from the air is total fiction,” Dr. McDonald said. While science has not found evidence that onions prevent illness, some still follow this folklore remedy and you can follow the discussion.
6. It’s okay to eat leftover onions. A social media report has circulated stating that onions become toxic after you cut them. “I suppose that comes from the concept that when you cut onions there is release of the sulfur-compounds, but I don’t know of any health risks from those compounds,” Dr. McDonald said.
7. Onions can prevent hair loss. You just have to rub onion juice directly on your scalp.

Onions can pack a powerful punch when added to foods. Although they cannot prevent illness, onions do have some health benefits and there are many reasons they are so appealing.

The post Food Facts: Seven Things You Might Not Know About Onions appeared first on Best Food Facts.

It is a widely circulated report such as this Facebook post about onions curing the flu, and we wondered many of the same questions. We reached out to Ruth MacDonald, PhD, RD, Chair and Professor of the Department of Food Science & Human Nutrition at Iowa State University.

Do onions absorb bacteria and cure illness?

Dr. MacDonald: “No, onions do not absorb bacteria. The idea that a vegetable would attract and suck into itself bacteria from the air is not even logical. The onion may turn black because it would eventually rot from both cell breakdown events and bacterial contamination if you left it out, not because it absorbs germs. Onions and garlic are slightly acidic, which could have antibacterial effects if you rubbed the juice on things, but these are much less effective than bleach or chemical antibiotics. Eating these vegetables provides antioxidants that can have health benefits, but they are unlikely to prevent or cure disease.”

Onions do contain sulfur compounds and were used in some cultures for medical purposes, but the effectiveness of these treatments is not significant.

The post also mentioned that you don’t need to refrigerate mayonnaise. Is this true?

Dr. MacDonald: “Mayonnaise that is made from eggs needs to be refrigerated. Products made from oils only may not require refrigeration – however, once opened, they will grow bacteria just as any food might, due to exposure from utensils or hands during use. It is best to refrigerate any mayonnaise after it has been opened.

“The possible sources of foodborne illness are many, especially in salads, and it is usually not possible to trace it back to the original source; however, modern technology is making that more possible. All foods can carry pathogens, and any food left at room temperature or above for more than 30 minutes can become contaminated to the point of causing illness. Pathogenic bacteria in those foods could grow at that temperature. The increased amount of the pathogen (or a toxin produced by the bacteria) in the food causes the illness when the food is consumed.”

Is it bad to feed onions to dogs, as mentioned in the post?

Dr. MacDonald: “I don’t know if dogs can eat onions – but I do know that stomachs do not ‘metabolize’ onions. The stomach of all mammals provides acid and enzymes that break down food prior to entering the small intestine.”

Previously, we asked Dr. MacDonald if it is OK to use leftover onions. Click here to learn more about the food safety rules concerning leftover onions.

What do you think about onions?

_{“Assorted onions” by Alice Henneman is licensed under CC BY 2.0.}

The post Do Onions Absorb Bacteria That Cause Illness? appeared first on Best Food Facts.

Why are antibiotics fed to livestock inside CAFOs or feedlots?

Dr. Davies:

Several purposes – mostly related to maintaining animal health. The most obvious use is for therapeutic reasons – to treat animals with disease; they may also be used for metaphylaxis – meaning if there is an outbreak of disease in a group of animals – which treats all animals because of their exposure to the affected animals. In some instances, antimicrobials are used following the approved label to improve feed efficiency.

Dr. Hurd:

As they say, an ounce of prevention is better than a pound of cure. Exclusively talking about feeding (antibiotics can also be administered via injection or water), antibiotics are fed to animals mainly for two purposes: to prevent illness outbreak or for growth promotion (the FDA calls this “production purposes”) – both of which allow the animals do better. This could be because in feed, antibiotics are preventing the animal from getting sick in the first place.

Note, however, that overall, 88% of all antibiotics in livestock are used for illness prevention or illness treatment, according to the companies who sell these antibiotics. The balance is to keep animals from getting sick. If we can prevent a barn of 1,000 animals from getting sick in the first place, then we won’t need to inject animals later – which is a riskier practice than prevention techniques.

Is there a risk to human health?

Dr. Davies:

There’s no such thing as zero risk. This has been analyzed for over 50 years; products have been approved for various uses since the mid-1950s. Most people accept the fact that when using antibiotics – in animals or humans, there is potential for resistance. The part that has been disputed is to what extent the use of antibiotics in animals could contribute to human health concerns. There are a lot of opinions, and some shortage of data. There have been some risk assessment studies done looking at antimicrobial uses and the probability of human disease and these have universally concluded that the human health risks are extremely low. There are almost no documented clinical cases where antibiotic resistance was unequivocally tied to animal antibiotic use. So while the risk is not zero, in my opinion, it is extremely low.

Dr. Hurd:

Regarding whether this presents public health concerns, the risk assessments that have been published in peer reviewed scientific journals (half a dozen or so) show that the chance of danger is extremely low. For it to be a concern, the resistant bacteria would have to be on the farm, then get to the consumer, then that consumer would have to fail to get better because of their resistance to antibiotics because of the antibiotic given to the animal. If you actually do the calculation, you’re statistically more likely to die of a bee sting than you are to end up enduring a couple days with diarrhea because of the above scenario. That’s not to say that we don’t see resistance in the population, but if you calculate the possibility that, for example, the resistant bacteria is going to make it from a farm in Nebraska to a dinner plate of a person in New Jersey who doesn’t respond to antibiotics, the risk is exceedingly small. This is because there are a lot of interventions in between. We make sure there are no livestock antibiotics on the meat before it leaves the packing plant. And most importantly, anyone handling meat should understand how to prepare it in a way that ensures all bacteria on the meat are killed during the cooking process.

We would like to extend our sincere condolences to the family and friends of Dr. Scott Hurd, who passed away on Thursday, March 27, 2014.

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