Death by meat

Death by meat

Processed protein may be convenient and delicious, but there's danger in every bite

It was just less than a year ago that worldwide consumers almost jumped out of their skin when the WHO's International Agency for Research on Cancer (IARC) categorised processed meats such as sausage, ham and bacon as not just unhealthy, but linked to cancer.

What is even more alarming in Thailand is the Foundation for Consumers announcement earlier this month that sausages are also detrimental to health.

Chalard Sue (Smart Buyers) magazine tested 15 samples of prepackaged sausages from a market and 14 of them were found to contain nitrate and nitrite -- chemicals used for food preservation. Of these 14, three were reported to have contained more nitrates and nitrites than the amount allowed under the Food and Drug Administration (FDA)'s standard. The rest had the chemicals, but not in high quantity. Of all the tested samples, only cocktail sausages under the Thai Sausage brand manufactured by Thai-German Meat Products Company Limited were found to contain zero nitrate or nitrite.

Such an announcement has triggered public paranoia as a few of the "lethal" sausages were from popular food brands.

For health and safety reasons, however, assistant professor in biological sciences Wenika Benjapong of Mahidol University's Institute of Nutrition suggested that consumers lessen the amount and frequency of their consumption of processed meats.

A consumer browses through a selection of pre-packaged sausages in a department store in Nonthaburi.

"If you eat processed meats every day, you simply put yourself at health risks," said Wenika.

Processed meats, according to Wenika, include not just ham, bacon and salami but also some Thai favourites like kun chiang (Chinese sausage) and naem (Thai-styled fermented sausage). In the manufacturing process of such products, two food additives, namely nitrate and nitrite, are usually added in the form of potassium nitrate, potassium nitrite, sodium nitrate and sodium nitrite. Regardless of the chemical terms, nitrate and nitrite are added to prevent the growth of bacteria in the food and to maintain the original pink colour of the meat.

"When fresh meat is exposed to oxygen, it might turn darker and people do not like that. Manufacturers, therefore, add nitrate or nitrite to the meat, which helps maintain its red pigment. You might notice even when we heat sausages, their colour does not change," she explained.

Also during the production, meat that is processed is likely to be contaminated with Clostridium botulinum, a bacteria which grows well in zero-oxygen conditions and is frequently found in canned, vacuum-packed foods or cured meat. Nitrate and nitrite, added Wenika, has the ability to block the proliferation of germs.

In Thailand, the use of nitrate and nitrite is allowed but in limited quantities as stated in the notification of the Ministry of Public Health (No.281) concerning food additives. No more than 500mg of nitrate per kilo of meat is allowed in the case of processed meats, while a maximum of 125mg of nitrite per kilo of meat is allowed given the toxicity of nitrite is more severe. If both chemicals are used, the amount is limited to 80mg per kilo of meat.

The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has set the acceptable daily intake of nitrate and nitrite at no more than 3.7mg and 0.07mg respectively per one kilo of body weight. Exceeding this safety curb means higher health hazards, depending on the amount and duration that the body is exposed to the said substances.

Nitrate and nitrite have acute and chronic consequences, said Wenika. If consumed in large quantities, immediate side effects include methemoglobinemia, or the inability of red blood cells to carry oxygen throughout the body. Other symptoms include fatigue, difficult breathing, headaches and a rapid heartbeat, which can be fatal.

"When exposed to acidity in the stomach, nitrites can react to compounds in the meat called amines. Together they form nitrosamine which, according to the IARC's cancer classification, is categorised as possibly carcinogenic to humans," Wenika explained, adding that despite the lack of scientific evidence to fully confirm nitrosamine as a cancer-causing agent, studies have found that excessive intake of nitrate and nitrite is associated with higher prevalence of cancer.

The IARC also stated that each 50g portion of processed meat eaten daily increases the risk of colorectal cancer by 18%. The IARC is able to conclude and classify that processed meats are carcinogenic to humans, based on a study on the link between processed meats and cancer conducted with more than 400 people.

"More consumption of processed meats thus means higher risk," said the assistant professor. But from consumer perspectives, nitrate and nitrite intake from processed meats can be unavoidable to a certain extent given the chemicals are undetectable to the naked eye. And consequently, Wenika recommended, reading food labels is of utmost importance.

If consumers are to buy sausages or any other processed meats, look for the approval sign of the FDA on product packages. Such a symbol certifies the products are screened that they do contain ingredients and compounds as stated in the labels.

Nonetheless, nitrate and nitrite might not be mentioned on product labels in a straightforward manner. As a result, Wenika suggested that consumers look for code number IND 249, 250, 251 and 252 -- food additive codes for potassium nitrite, sodium nitrite, sodium nitrate and potassium nitrate, respectively. These numbers on product labels means they contain the chemical compounds.

"For safety, you might also opt for processed meats that state on their packages they contain no food preservatives and colour fixatives," advised Wenika. "Children should not eat more than four pieces of 10cm-long sausage per week."

The cooking temperature and approach for processed meats also matter. According to a 1979 study, fried bacon was found to be high in nitrosamine when compared to bacon that was not exposed to heat. Clostridium botulinum can also be killed when heated to over 80C for more than 10 minutes.

"Sausages when grilled or fried are likely to release more nitrosamine than steamed," said Wenika. "But in all, eat less processed meats and more fruit and vegetables. They are sources of vitamin C, vitamin E and phenolic acids, which are able to inhibit nitrosamine formation."

Do you like the content of this article?
COMMENT (3)