Is Eating From a Dented Can Safe? Canned Food and Botulism
It is indeed true that eating canned food from a bulging or badly dented can may not be safe and can cause illhealth. Why? Because food that has been in a dented can or or another damaged can may contain Clostridium botulinum, bacteria that has been linked to botulism.
Botulism, also known as botulinus intoxication, is a rare but severe illness that affects the nervous system and leads to paralysis. Botulism typically affects the facial muscles first and then spreads to other parts of the body. If the paralysis spreads to the breathing muscles, respiratory failure may follow. The first symptoms of botulinus intoxication usually appear 8-36 hours after you eat food contaminated by the bacteria.
The Clostridium botulinum bacteria that may live in improperly processed or canned food can form spores, reproductive structures that are able to survive in unfavorable conditions. These spores produce highly heat-resistant toxins (poison) which can cause severe botulinus intoxication, even when the poisoned food is eaten only in small amounts.
However, contaminated food from dented cans or other improperly stored or prepared foods are not the only potential sources of the Clostridium botulinum bacteria; it is also possible to get botulism through contamination of a wound by the bacteria. Person to person transmission of botulism does not occur.
Due to the high standards of food hygiene in most western countries, the chances of getting food-born botulism from canned foods bought in these countries is extremely low. In the U.S., for example, only about 110 cases of botulism occur every year. Home-canned foods, especially those with low acid content (such as asparagus, beets, carrots, corn and green bean) are more likely to cause food-borne botulism in western countries than commercially canned products.
Despite the low likelihood of getting food-born botulism from canned foods in the western countries, it is important to stick to the safety precautions that authorities recommend. The U.S. Department of Agriculture (USDA), for example, gives the following safety advice with regard to eating canned food:
"NEVER USE food from containers that show signs of botulism: leaking, bulging, rusting, or badly dented cans; cracked jars; jars with loose or bulging lids; canned food with a foul odor; or any container that spurts liquid when opening. DO NOT TASTE THIS FOOD! Even the tiniest amount of botulinum toxin can be deadly."