Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form


"By denying scientific principles, one may maintain any paradox." – Galileo Galilei

IARC’s Classifications Throw Cold Water on Summertime Fun

Millions of Americans would probably agree that any recipe for summertime fun should include plenty of grilling, picnicking, and wearing lots of sunscreen.

But if the International Agency for Research on Cancer (IARC) is to be believed, many of the main ingredients that are critical to these quintessential summer activities are “possibly,” “probably,” or downright carcinogenic.

In fact, IARC’s Monographs Program has actually claimed that a myriad of items essential for summertime fun — including hot dogs, brats and hamburgers for the grill; lunchmeat for that family picnic; and sunscreen to protect you from the sun —ALL contain key ingredients that are potentially carcinogenic.

Let’s take a closer look at the flawed methodology that’s behind IARC’s decision to categorize these summertime items as carcinogenic.


Hot dogs, brats and lunch meats – as bad as smoking?

IARC has classified processed meats such as hot dogs, bratwurst and lunch meat as “carcinogenic to humans” – the highest ranking on the agency’s carcinogen classification and in the same category as plutonium and smoking tobacco. But as is often the case with IARC, its processed meat classification lacks context and a comprehensive body of solid evidence to support it.

Even IARC’s parent organization, the World Health Organization (WHO), has pushed back and clarified that “the health risks of processed meat are vastly different of those cigarettes” and that people should not stop eating meat. University of Reading nutrition expert Gunter Kuhnle has also noted that IARC’s processed meat classification “does not mean… that eating bacon is as bad as smoking,” and that, “processed meat can be part of a healthy lifestyle – smoking can’t.”

In other words, experts agree that eating too much processed meat is probably not good for one’s health, but that processed meat can be part of a healthy diet if enjoyed in moderation.


Hamburgers: “probably carcinogenic”?

IARC has also declared that another all-American grilling favorite, red meat, is “probably carcinogenic” to humans. Though we don’t know exactly why IARC reached this determination (it has yet to release the Monograph more than a year and a half after the announcement was made) it is already in dispute.

Among those pushing back on IARC’s announcement is (again) its own parent agency, the WHO, which set the record straight by stating:

“… meat provides a number of essential nutrients and, when consumed in moderation, has a place in a healthy diet.”

Ian Johnson of the UK-based Institute of Food Research has also noted:

“There is little or no evidence that vegetarians in the UK have lower risk of bowel cancer than meat-eaters.”

And nutritionist Elizabeth Lund from Norfolk in England has noted that there is evidence that a balanced diet, including red meat, can actually lower the risk of colorectal cancer (CRC):

“Overall, I feel that eating meat once a day combined with plenty of fruit, vegetable and cereal fibre plus exercise and weight control, will allow for a low risk of CRC. It should also be noted that some studies have shown that if meat is consumed with vegetables or a high-fibre diet, the risk of CRC is reduced.”

All we know for certain at this point is that IARC’s decision was based on “limited evidence” and did not take into account recent large cohort studies that found no significant associations between eating red meat and cancer. These were generally dismissed by IARC. also reported that of the 800 studies IARC screened for the Monograph, experts considered less than six percent of the database sufficiently useful to determine a link between meat and colorectal cancer.

It is also evident that IARC’s decision rested largely on the so-called “strong” mechanistic evidence that appears to be from far-less reliable observational studies, which were limited by factors that likely skewed the results.


You just can’t win: IARC says key ingredients in sunscreen can give you cancer

IARC has classified natural sunlight as “carcinogenic to humans,” a widely-accepted truth by credible organizations such as American Cancer Society and Cancer Research UK.  But the good news is that sunscreen can protect us from harmful ultraviolet rays with no harmful side effects, right? Not so, according to IARC.

IARC has classified a key component of physical (mineral-based) sunscreen — titanium dioxide — as “possibly carcinogenic” to humans, despite the fact that they found “inadequate evidence in humans.”

In fact, IARC based their decision on a small amount of evidence observed in rats, primarily due to excessive inhalation. This is something that’s clearly not happening when you put sunscreen on your skin, even in the case of spray-on sunscreen, if used as directed.

According to Warwick L. Morison, Professor of Dermatology at Johns Hopkins University and Steve Q. Wang Director of Dermatologic Surgery and Dermatology at Memorial Sloan-Kettering Cancer Center, study after study has shown that sunscreen is safe:

“The concern is that nanoparticles can be absorbed by the skin and harm living skin tissue. However, current research indicates that fears about absorption are unwarranted: Sunscreen is applied to the stratum corneum, the outermost layer of skin, which is made up of dead cells, and multiple studies have shown that nanoparticles do not penetrate living skin. Additionally, in sunscreen formulas, it appears that nanoparticles tend to clump together to form larger-than-nano-sized particles.”

“The safety of sunscreens has now been studied in labs and on live subjects by research scientists for years, and the evidence that sunscreens are safe and effective is overwhelming.” (emphasis added)

The Cancer Council Australia, said in 2016,

“So far, the current weight of evidence suggests that titanium dioxide and zinc oxide nanoparticles do not reach living skin cells; rather, they remain on the surface of the skin and in the outer layer of the skin that is composed primarily of dead cells.”

The key takeaway here is: There has been no evidence of titanium dioxide causing cancer in humans since it became commercially available nearly a century ago.



Not only have these determinations been based on scant or virtually non-existent evidence in humans, but IARC has chosen to group some of these items alongside carcinogens such as plutonium and smoking tobacco — only compounding public confusion and undue alarm.

While IARC seems to be determined to put a damper on summer fun, close scrutiny of IARC’s methodology and the lack of context in IARC’s messaging reveals that these summer activities are perfectly safe.