Researchers and health organizations such as the American Cancer Society have alerted Americans for decades that processed meats - hot dogs, bacon and sausage, for example, may increase the risk of cancer.
But when the World Health Organization's International Agency for Research on Cancer (IARC) announced last week that processed meats were carcinogenic following a review of hundreds of previous studies, and that red meat is "probably" carcinogenic, those previous messages were amplified.
The report informed us how confident they are about whether processed and red meat cause cancer. IARC's group of 22 experts from 10 countries categorized processed meats in Group 1, alongside alcohol, asbestos and tobacco smoke, meaning there is enough evidence to conclude that it causes cancer in humans. However, processed meats create a much lower level of risk compared to those carcinogens.
Red meat was placed in Group 2a, meaning there is limited evidence that it has a carcinogenic effect.
For meat lovers, the news was met with skepticism and vows to continue eating meat. East Texans like Ken Morrow responded on Facebook that no one food seems to be safe from scrutiny.
"Fill in the blank with eggs, milk, butter, cheese, coffee, sugar," Morrow said. "... All of which they later ‘discovered' aren't so bad after all - and in some cases, are pretty darned healthy. I stopped listening to these reports quite some time ago."
The North American Meat Institute on Monday called the report by the IARC panel "dramatic and alarmist."
"IARC's decision simply cannot be applied to people's health because it considers just one piece of the health puzzle," Betsy Booren, North American Meat Institute vice president of scientific affairs, said in a statement.
Others noted that they've already started limiting any meat that doesn't appear to be close to its natural state.
Esther Cooks Medlock, who grew up in a rural area, said she believes meat today is different from years ago.
"I don't eat very much red meat now," she posted on Facebook. "Meat with the color addition - I don't buy."
Melinda Coker, local health and wellness coach and author of the 2010 book "Diet and Cancer: Is There a Connection?" has been advocating a plant-based diet for at least seven years. Losing some close friends to cancer, she's hopeful the WHO report will motivate people to reduce their consumption of meat.
"My reaction was, ‘Why are they just now saying this? It's been known for a long time," Mrs. Coker said. "But at least it's gotten everyone talking about it again so maybe that's good."
Dr. Bola Olusola, a gastroenterologist at UT Health Northeast, said while the information presented in the WHO report isn't new, the international organization's influence places more weight on what others have been saying.
"I think this is going to impact, in some way, people's choices," he said. "When the WHO says something, most people look at it as an unbiased statement and more people take it a little more seriously."
Poor diet, which includes one high in processed meats, is among the modifiable risks largely responsible for the top two leading causes of death - heart disease and cancer, according to the Centers for Disease Control and Prevention.
Evidence that processed and red meats cause cancer has been mounting for decades. IRAC reviewed 800 studies, including a 2011 study that concluded a "high intake of red and processed meat is associated with significant increased risk of colorectal, colon and rectal cancers.
The overall evidence of prospective studies supports limiting red and processed meat consumption as one of the dietary recommendations for the prevention of colorectal cancer."
Researchers said for each 50-gram portion of processed meat eaten daily - the equivalent of one hot dog or two slices of bacon - it increases the risk of colorectal cancer by 18 percent.
Scientists are still not sure how processed and red meat may make cells cancerous, but there are theories, Olusola said.
It's not that red meat by itself is bad. Red meat is high in protein, vitamin B, iron and zinc. The risk of cancer may be a result of how meat is prepared.
"When you process that meat for preservation or adjust the taste of it - you salt it or cure it or barbecue it - it can then generate some chemicals called hydrocarbons. They have been shown to lead to cancer."
Cooking also can produce known or suspected carcinogens. According to the WHO report, "high-temperature cooking by pan-frying, grilling or barbecuing generally produces the highest amounts of these chemicals."
Olusola also notes that food stays in the colon longer than any other part of the GI tract, meaning it gets exposed to potentially cancer-causing compounds over a longer period of time.
This doesn't mean people should never eat meat, or even processed meat. But how much processed and red meat individuals eat may be up for debate, as recommendations differ.
The American Cancer Society and an advisory committee for the upcoming 2015 U.S. Department of Agriculture's Dietary Guidelines for Americans simply acknowledge that a healthy diet is one that is "higher in vegetables, fruits, whole grains, low- or non-fat dairy, seafood, legumes and nuts; moderate in alcohol (among adults); lower in red and processed meat; and low in sugar-sweetened foods and drinks and refined grains."
The American Heart Association advises that individuals eat less than six ounces of lean meat, skinless chicken or fish per day.
"The data is clear for processed meat and for red meat," Olusola said. "We need to know that the risk is there so we should adjust our diets properly.
"Just like anything in life, an excess of anything, no matter what it is, is bad for you."
WHAT YOU NEED TO KNOW ABOUT PROCESSED MEAT
What is processed meat? Processed meat refers to meat that has been transformed through salting, curing, fermentation, smoking or other processes to enhance flavor or improve preservation. Most processed meats contain pork or beef, but processed meats may also contain other red meats, poultry, offal or meat by-products such as blood. Examples include hot dogs, ham, sausages, corned beef, beef jerky and canned meat.
What is red meat? Red meat refers to all types of mammalian muscle meat, such as beef, veal, pork, lamb, mutton, horse and goat.
So what does this report from WHO mean?
The report, which was a review of 800 previous studies, tells us whether processed and red meats cause cancer. It does not determine how cancerous they may be to individuals. In other words, the IARC didn't assess the risk of people getting cancer, but announced there is proof that processed meat, and probably red meat, does cause cancer in humans. The report also does not offer dietary recommendations for any governmental entity, communities or individuals.
Why is processed and red meat grouped with cigarettes and asbestos?
These don't all have the same level of risk of cancer in humans. The IARC classifies what is likely to cause cancer only. Group 1 is for things that have sufficient evidence that it causes cancer. Group 2a are for things that probably cause cancer. Group 2b means it may possibly cause cancer. Group 3 items are not classifiable to its carcinogenicity to humans; and Group 4 means an item probably does not cause cancer.
How much processed and red meat is too much?
There is not one specific recommendation. The American Cancer Society and the U.S. Department of Agriculture's Dietary Guidelines for Americans have simply said to limit intake of red and processed meats. Health experts have also advised considering smaller portions (American Heart Association says less than 6 ounces per day). Health officials typically recommend eating various foods "in moderation."