Has this been observed in other countries too or just in USA/North America? Exposure to various chemicals and food habits are vastly different, if those are the source (which are the first culprits I'd consider) of cancer increase, then numbers should also be very different elsewhere.
>Dietary changes in the population seem the first place to look.
Yes but we must unpack that. It's not just WHAT you eat (and even then, a 2024 tomato is not a 1950 tomato), it's how it was grown, how it was processed, how it was prepared, etc. Most studies don't even scratch the surface of this
Food additives are a part of that as well and there is some evidence. E.g. gelatin was replaced by carrageenan in most foods which has been shown to trigger colon cancer.
Drinking water is another such. NDMA is a byproduct of water disinfection and industrial processes (in drinking water as a result of chloramine disinfection, and in chlorinated wastewater used for aquifer recharge) and has been shown to trigger colon cancer. 35-40% of the municipally-treated water in the US is now disinfected using chloramine, a percentage which has nearly doubled in the last decade
Degraded carrageenan, or poligeenan, is not safe to eat. Research in animals indicates that it causes gut tumors and ulcers, and may even trigger colon cancer.
Because of the possible danger, fewer studies have investigated the potential effects in humans.
Findings like these have led the International Agency for Research in Cancer to list poligeenan as a possible human carcinogen.
This means that the agency has reviewed the evidence that poligeenan can cause cancer in animals and concluded that it may have the same effect in humans.
Some scientists are concerned that food-grade carrageenan is also dangerous. This is because various studies, dating back to the 1960s, show that the substance may degrade and become toxic when it mixes with stomach acid.
The medical community is unsure to what extent carrageenan degrades in the digestive system. This means that we do not know if any amount is toxic. It is important to note that no related studies have involved human participants.
Findings of a review from 2017Trusted Source indicated that even non-degraded carrageenan can cause inflammation and bowel disorders, suggesting that this substance may contribute to ulcers and IBD.
However, authors of a 2018 reviewTrusted Source concluded that there is not enough evidence to draw conclusions about the exact health effects of carrageenan.
Anecdotal evidence suggests that eliminating carrageenan from the diet can provide relief from digestive problems, such as bloating and IBD. However, these reports are not the result of scientific research.
It's not purely a screening issue -- there are no mandatory screenings for teenagers, so any screenings done would be in response to showing symptoms. That said, as awareness of incidence of youth colorectal cancer becomes more widespread, it is more likely to be seen as a possibility, and thus increase the number of tests run.
As always there are rabbit/turtle/bird situations; it's impossible to say how many of these early detections are of slow-growing benign conditions that left untreated would never pose a threat to quality of life or morbidity or mortality. But because these tests are not done by default, but only in response to some reported symptoms, it is more likely that there is an actual increase in incidence.
It does not appear that this is yet a published study, which might give more data on the prevalence of testing that might in turn give an idea of how much the screening effect contributes.
I was diagnosed with Stage 3 rectal cancer in 2017, and a doctor doing a research study told me incidence for people under 50 had risen 20% in a decade. I imagine diet plays a significant role, insofar that our diets have changed dramatically in the last 50+ years. However, I also imagine the food production chain is a contributing factor. How much is anyone's guess.
TLDR Strong evidence diet (more sugar, more alcohol, less fiber, highly processed foods in general), western disease, less exercise are contributing factors.
Following colorectal cancer rates of folks who get on GLP-1 agonists (semaglutide) might provide stronger signal.
A lot of people have been investigating this and there isn't super hard conclusive evidence. That said, you are looking for zebras instead of horses.
For example, in Japan, gastric cancers are already much higher than in the US (like 5x more frequent), and there is evidence it is due to higher salt, smoked foods, H. pylori, genetics, and higher screening. If you are looking for the impact of a specific environmental pollutant, Japan v. US has a great example too: professionals hypothesize that because their cigarettes are equipped with a different kind of filter, Japanese OR of lung cancer due to smoking is like 15, compared to the US's 30-60.
There is likely a combination of trends, and maybe environmental pollutants play a little bit of a role. But you could definitely ban PFAS and microplastics - whatever that means - and still observe obesity rates rising, more sedentary lifestyles, more salt and processed food intake, etc., and maybe you'd get 280% increase in colorectal cancer instead of 325% for the next 20 years. Ultimately you could spend your money investigating PFAS and microplastics, or you could spend it investigating all the soap people put on their assholes, all the weird cosmetics they use on their mouth and face, the horrible shit they eat, or any number of things whose incidence rate is also a chart going up and to the right, but might interact with the colon quite literally more directly.
The numbers in the article are striking. That said, there are few details on the methods and this is not published or peer reviewed data yet.
If at all true, what is driving it is a great question.
From 0.3 per 100,000 to 1.3 per 100,000. Not saying this isn't significant, but whenever you see a phrase like "increase of x%" it's often worth your time to see what that is in absolute terms.
It's easy to jump to conclusions from this one single meta analysis however based on my experience I would want to see a more deep dive review. I would guess that underreporting, especially in the pre-2010 era after which electronic medical records became much more prevalent, as well as the changeover to ICD10 from ICD9, are likely culprits. Data quality in healthcare today is a D- at best, 20 years ago it was absolute and total garbage. Though this persists today, the excel 65k row limitation and excel date bugs are reponsible for an unimaginable amount of healthcare data destruction.
Up until 2012 even, most CDC reporting was done as manual chart reviews typed into an excel sheet. That was a very error prone process.
The EPIC Oxford study showed that vegetarians are more likely to die from colon cancer than the control group, "health food buyers". But the effect canceled more or less out, because the health food buyers did die more often from CVDs.
Cellphone use? Colon position is close to pocket height, where our cellphones tend to stay while not charging or being actively manipulated. Someone should try to correlate tumor starting location with handedness. If it tends to start the same side the dominant hand is, that would be a smoking gun.
Everyone here is complaining about the nature of the proposed natural experiment and I’m just here thinking “where are the pockets on OP’s clothes?”
Phones are stored primarily in front pockets that are nowhere near the colon in terms of biology (almost everyone has relatively dense meaty quads and femurs between the thigh and colon) or the inverse square law.
If that were the case, you wouldn’t see 10-14 year old see a 500% increase and the increase would be closely correlated with when they got the phone, etc.
Also, the article seems to suggest that the absolute incident rate isn’t high - which could mean that we are likely getting better at detection rather than increase in underlying prevalence.
After my first colon cancer, I read all I could find about cell phones and cancer, and did not find anything substantial. The most interesting was an indication that perhaps the radiation could impair the immune system's ability to fight cancer. But I think that stress of modern life would affect the immune system more.
I would be more worried about the increase of chemicals in the environment, such as PFAS and nanoplastics.
Well it's supposedly all non-ionizing radiation, which can't cause DNA damage and cancer links are controversial at best, but I agree it should be looked at statistically. Here are some other conjecturable variables:
With the 10-19 year-old groups, you're looking at very low overall numbers, so a 400% increase might mean something like from 10 to 50 cases a year in the US. Still, shedding light on this anomaly might uncover a major causal pathway in the older cohorts.
What about all the adults that got phones between 2000-2015 and use them since then to today?
I'd expect a 50 year old person that uses a phone for the past 25 years to be full of holes if cellphone usage has any effect on kids using them for few years. Especially since older phones were radiating much more energy.
Not necessarily, assume that cellular radio emissions effects on cells is like really a mild form of radiotherapy. It would mostly impact some cells undergoing mitosis while having almost no impact on mature slowly dividing cells.
I am not saying that cellular radio are harmful but it's cumulative impact on dividing cells should be tested to exclude that possibility.
The human digestive tract is constantly creating new cells, it's a lot like skin in that sense. I doubt teens have much significantly more mitosis in their butts compared to adults.
I saw a documentary where a startup in California was doing quite well selling faraday cage underwear. I was really scratching my head and wondering if they were just grifting or if it was addressing a serious issue. These were highly refined products.
Some bacteria secrete small iron oxide crystals and are able to use those to sense magnetic fields[1]. Our guts are full of bacteria. Wonder if a nearby RF emitter can cause some of them to run amok. They surely tested the effects of cellphones in human tissues, but I doubt the same was done to bacterial cells.
> bacteria secrete small iron oxide crystals and are able to use those to sense magnetic fields
There is preliminary evidence "that MTB in the gut are associated with grey matter volume in magnetite-rich brain regions related to orientation and navigation" [1].
> Wonder if a nearby RF emitter can cause some of them to run amok
This was explored (and dismissed) in the early noughties [2], when cell-phones-cause-cancer was enjoying a halcyon. (I think it was radiation from CRTs before that. Probably non-organic vegetables today.)
