Even if you have a healthy immune system, you can get sick from the food you eat, if it is not handled and prepared properly.  At even greater risk are young children, the elderly, pregnant woman, and those with compromised immune systems.

The body does have  defenses to protect itself from harmful bacteria.  Since many bacteria cannot live in an acidic environment, the gastric juices, being acidic, are the first defense against food-born pathogens.  Unfortunately, the elderly and the very young produce fewer of these acidic gastric juices and so are at greater risk. Another defense is the normal bacterial flora that exist in the gastrointestinal tract.  These prevent harmful bacteria from flourishing.  However, some medication such as antibiotics can destroy normal healthy bacteria and allow harmful ones to thrive.

One of the most common types of bacteria found in animals, water, vegetation, soil, sewage, and hence food, is called listeria.  Listeria contaminated foods will not change in appearance, taste, or smell.  This bacteria can exist and grow even on refrigerated foods.  Listeria is responsible for one rare but serious disease called listeriosis, which attacks the very young, the elderly, pregnant woman, and those with compromised immune systems.  In these individuals, listeriosis can cause symptoms similar to flu, such as diarrhea, nausea, vomiting, and muscle aches.  In serious cases, it can cause meningitis, an inflammation of the covering of the brain.

To avoid the possibility of becoming sick from the food you eat, follow these simple precautions.

1.  Clean all fruits and vegetables before you eat them.

2.  Defrost frozen food in cold water or in a microwave, never at room temperature.

3.  Freeze or refrigerate all perishable foods within two hours of purchasing them.

4.  Refrigerate or freeze leftovers as soon as the meal is over.  Keep them in the refrigerator for no more than four days.

5.  Read all labels on packaged foods and follow exactly the directions provided.

6.  Keep food preparation surfaces immaculate.  Immediately disinfect surfaces on which you have prepared raw foods, especially meats and fish.  Clean all containers and utensils used for preparing raw foods before you use them again.

7.  Make sure that the temperature of your refrigerator does not rise above forty degrees.  Colder is better.

8.  Clean and disinfect your refrigerator regularly.  Clean up spills immediately.

9.  Never use food beyond the “best before” date or any food that does not look, smell, and taste fresh.  Return it to the store and demand a refund.

10. If you have any high-risk individuals in your household, be especially vigilant.

A good book about healthy eating is Eat, Drink, and Be Healthy: The Harvard Medical School Guide to Healthy Eating