A 2015 report by the World Health Organization (W.H.O.) placed processed meats, especially bacon, alongside cigarettes as a leading cause of cancer. Eating two bacon slices a day, it concluded, makes developing bowel cancer 18 percent more likely – enough for it to be ranked as a group 1 carcinogen. With some experts criticizing the findings, however, do bacon-lovers have real reason to worry?
While the W.H.O. findings generally concerned processed meats – namely ham and sausages, as well as bacon – it also concluded that red meats are “probably carcinogenic.” It did say, however, that evidence of a link between them and cancer was limited.
What the W.H.O. did conclusively reveal, though, is that processed meats are as dangerous as smoking, drinking alcohol and asbestos when it comes to cancer-causing potential. They all sit alongside one another in group 1, with red meat having been placed in group 2A.
What exactly constitutes a processed meat? Well, any meat product that’s been cured, salted, smoked or fermented – which means that beef jerky, corned beef and hot dogs all count. Such methods either add to the product’s taste, or allow it to keep for longer.
For something to be placed into group 1, the W.H.O. needs to have discovered “sufficient evidence” of its cancer-causing properties. This had already been the case with asbestos, tobacco smoke and alcohol – but the things placed into group 1 don’t necessarily pose the same degree of risk.
Feeling skeptical, and in need of some supporting data? Take mortality figures from the Global Burden of Disease Project, for example. It estimates that approximately 34,000 people around the world die from cancers linked to processed meat every year.
This is far smaller than the number of people killed by alcohol-related cancers. At the last count the number of annual fatalities from booze totaled approximately 600,000. Or to put it another way, more than 17 times the number of deaths linked to processed meat.
Cancers linked to smoking tobacco are deadlier still. Staggeringly, about one million smokers lose their lives to the disease every year. Clearly, this statistic dwarfs the figure put on cancer deaths linked to processed meat.
But while drinking and smoking are gradually falling out of favor, meat consumption is on the rise among people on low and middle incomes. This is according to the W.H.O., which has suggested that processed meat could therefore become a public health concern.
Its conclusions were based on over 800 human-centric cancer studies. Of those analyses, approximately half of them presented findings on processed meat. A further 700 looked at evidence surrounding red meat.
The W.H.O. did stress, however, that meat has certain nutritional benefits – an observation with which cancer charities have generally concurred. Cancer Research UK, for example, has said the findings are a reason to reduce the amount of processed meat we eat, rather than give it up altogether.
Some scientists, however, have been critical of the W.H.O. findings. Dr. Ian Johnson, of the U.K.-based Institute of Food Research, said that while there was a concrete link between processed meat and bowel cancer, the effect, he believed, “is relatively small.”
“It is certainly very inappropriate to suggest that any adverse effect of bacon and sausages on the risk of bowel cancer is comparable to the dangers of tobacco smoke,” Johnson commented. “[Smoke] is loaded with known chemical carcinogens and increases the risk of lung cancer in cigarette smokers by around 20-fold.”
Food nutrition scientist Dr. Gunter Kuhnle, of the University of Reading, expressed concern over how the findings had been reported. “The W.H.O.’s decision means that there is sufficient evidence that processed meat consumption causes cancer,” he explained. “It does not mean, as purported by many stories in the media, that eating bacon is as bad as smoking.”
Kuhnle added that, while smoking three daily cigarettes increased the chances of developing lung cancer by 600 percent, eating 50 grams of processed meat raised the chances of colorectal cancer by just 20 percent. The difference, then, is pretty big.
So what exactly is it about bacon that increases the risk of cancer? Well, the danger doesn’t lie with the meat but, rather, the curing salt used to preserve it. The nitrate it contains can encourage the development of nitrosamines – which, weirdly, are normally found in balloons – in the tracts of the intestines.
“Many nitrosamines are carcinogenic compounds,” Dr. Kuhnle explained. “As they can react with DNA and eventually cause tumors to form. Moreover, nitrosamines induce a specific mutation pattern which is found in many colorectal tumors.”
What now, then, for bacon eaters? Well, the old adage about “everything in moderation” certainly rings true. And in this case, moderation equates to no more than two slices per day.
Things may get easier if the bacon industry acts on the W.H.O. findings, either by looking into new products or updating its dietary advice. According to Dr. Kuhnle, though, the industry should brace itself for a “short-term impact” on sales.
But while those findings were no doubt concerning, another research project came to light back in April 2019. On that occasion, three experts took a closer look at the connection between processed meats and the development of colorectal cancer. By the end of the process, they uncovered some truly troubling results.
The study was eventually shared in the International Journal of Epidemiology, with the research itself taking place in the United Kingdom. As for the test subjects, about 500,000 people signed up for the cause. And by design, all of those individuals were aged between 40 and 69 years old.
To give you a better idea of how the study worked, here’s a simple breakdown. The aforementioned test subjects were rounded up over a four-year period, starting in 2006. The recruitment subsequently came to an end in 2010, but the researchers’ work didn’t conclude there, as we’re about to find out.
When each person came on board with the study from 2006 to 2010, they answered a “short food-frequency questionnaire” that outlined their eating habits. From there, the study authors then monitored these individuals for more than five years on average. During that time, they made some very worrying discoveries.
Indeed, the researchers were able to compile a number of statistics relating to the consumption of processed meat products. Prior to the publication of the study, the U.K.’s National Health Service (N.H.S.) had advised that people should aim to eat no more than 70 grams each day. As it turned out, some of the test subjects just went over that figure.
However, while the difference seemed quite small on paper, the long-term ramifications were potentially dangerous. So for the individuals who consumed roughly 76 grams of processed meat every day, their risk of getting colorectal cancer went up. That suggestion was only strengthened when compared to the test subjects who didn’t eat as much.
Statistically, the researchers claimed that the bigger eaters were 20 percent more likely to get the disease than those who consumed 21 grams each day. The latter measurement is comparable to a single ham slice, which you might eat for lunch. Meanwhile, 76 grams is said to be similar to a quarter-pound hamburger.
Unsurprisingly, that number could leave a lot of meat-lovers very concerned. After all, if they’ve been following the advice from the N.H.S., these results strongly hinted that 70 grams might still be putting them at risk. And to make matters even worse, the study’s eye-opening figures didn’t stop there.
In addition to the previous stats, the researchers discovered that food such as bacon was more dangerous than traditional red meats too. According to the study, your chances of developing colorectal cancer goes up by 20 percent whenever you add 25 grams of the former to your diet. If you’re trying to visualize that measurement, here’s an example.
A 25-gram helping of processed meat is said to be similar to a lone bacon slice. Comparatively, a red meat serving of around 50 grams raises your chances of getting cancer by 19 percent. That particular measurement is akin to one lamb chop, or a chunky slice of beef come dinner time.
At the end of the study, the researchers confirmed that more than 2,600 test subjects had been diagnosed with colorectal cancer. Of these, more than 1,500 of those cases were attributed to the men. Following the paper’s publication, one of the authors came forward to reflect on the results.
His name was Tim Key, and he worked for the cancer epidemiology unit at the University of Oxford. Alongside him, Key was joined by two fellow researchers named Neil Murphy and Kathryn Bradbury on the study. After their hard work, the first then released a statement talking about the team’s findings.
Key said, “A small amount of processed meat seems to have the same effect as a large amount of red meat. Our results [also] strongly suggest that people who eat red and processed meat four or more times a week have a higher risk of developing bowel cancer than those who eat red and processed meat less than twice a week.”
At that stage, Key wanted to make something else clear when discussing the results. In the past, similar studies had been conducted by other researchers, especially back in the 1990s. To that point, he added, “Diets have changed significantly since then, so our study gives a more up-to-date insight that is relevant to meat consumption today.”
Meanwhile, in addition to the stats that we previously highlighted, the paper briefly touched upon the negative effects of alcohol as well. Key and his colleagues revealed that your chances of developing colorectal cancer would rise by 8 percent if you consumed 10 grams each day. Yet there were some positive findings in there too.
For instance, the study noted that the test subjects who incorporated fiber and cereal into their daily diets reduced their cancer risk by 14 percent. That particular result also lined up with the findings of an older project from 2011. On that occasion, the British Medical Journal published a paper detailing the connection.
The study’s authors found that for every 10 grams of fiber consumed each day, a person’s risk of contracting bowel cancer would fall by an equivalent percentage. In the end, they advised people to add more cereal to their diets going forward. Given what we now know about the later paper, it was a sound suggestion.
Furthermore, one of the bigwigs at the Beating Bowel Cancer organization had welcomed the findings at the time. Indeed, while speaking to the BBC News website in 2011, its chief executive Mark Flannagan also made another notable point. He said, “These results support what we already know about the link between dietary fiber and a reduced risk of bowel cancer.”
“Although more work is needed to clarify the quantity and types of fiber we should be eating to reduce risk,” Flannagan added, “we recommend that people eat a healthy balanced diet that includes plenty of dietary fiber. It’s encouraging to know that simple changes to your diet and lifestyle could help protect you from the U.K.’s second-biggest cancer killer.”
By the time Key’s team’s study was published in 2019, Cancer Research U.K. confirmed that only three other forms of cancer were more prevalent in the country. Prior to that, it’s believed that an average of 42,042 colorectal cancer diagnoses were made each year between 2014 and 2016. However, this isn’t just restricted to Britain.
Indeed, colorectal cancer is a massive problem in America as well. To give you some idea of its scale, the American Cancer Society claimed that over 51,000 people would succumb to the disease in 2019. So while the aforementioned studies have revealed some interesting connections between processed meat and cancer, these numbers suggest that more has to be done.