Cancer rates appear to be skyrocketing in people under 50 [1][2].
Gen X, Millennials, and even Gen Z are being diagnosed at significantly higher rates than previous generations were at the same age.
So what is going on? A landmark study has provided some tantalizing answers [3].
The story turns out to be nuanced, and experts are divided about how to account for what the data shows. But there is one finding they all agree upon that is absolutely vital to know in order to manage and lower cancer risk.
Table of Contents
Data Trends and Possible Reasons
How bad are the numbers when it comes to cancer and young people?
A massive analysis published in 2023 in the British Medical Journal analyzed data on 29 cancers across 204 countries [4].
Early-onset cancer—defined as cancer diagnosed between the ages of 14 and 49—increased by 79.1% between 1990 and 2019 [4].
The most damaging early-onset cancers in terms of deaths were breast, tracheal, lung, stomach, and colorectal cancers [4].
This is not the direction anyone wants to be moving. And it raises a crucial question: what is driving the increase?
Several theories have emerged—and one unexpected turn involves the gut's microbiome.
Microbiome and Diet
The microbiome is central to human health. When it becomes unbalanced, it can increase inflammation and even contribute to cancer [5].
There is growing evidence that early-onset colorectal cancer, in particular, is associated with changes in the microbiome [5].
A major driver of microbiome changes is diet. The modern Western diet appears to trigger specific shifts in gut bacteria. In fact, mice fed a Western diet developed more colorectal cancer [5].
Some of the dietary components that negatively impact the microbiome include red meat and pre-packaged, highly processed foods [5].
One reason is that these foods often strip away fiber—a key nutrient that feeds beneficial gut bacteria and supports microbial diversity. Without fiber, the microbiome becomes imbalanced, inflammation rises, and cancer risk increases [6].
Research has shown that ultra-processed foods are associated with:
- A decrease in microbial diversity
- Lower levels of beneficial bacteria like Akkermansia muciniphila and Faecalibacterium prausnitzii
- An increase in pro-inflammatory microorganisms [6]
Other Contributing Factors
Beyond diet, researchers have proposed other risk factors for the rise in early-onset cancers:
- Chronic stress can accelerate aging and may increase cancer risk [7].
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Environmental exposures in younger generations that were not common in older ones, such as:
- Antibiotic use, which is associated with early-onset colon cancer [8]
- PFASs (also known as "forever chemicals"), which may increase breast cancer risk [9]
- Microplastics, which could disrupt development and promote carcinogenesis [10]
- Lower breastfeeding rates, which are linked to higher breast cancer risk later in life [11]
- Sedentary lifestyle is another concern. One large study found that being inactive is associated with higher cancer incidence, earlier onset, and shorter life expectancy [12].
Being sedentary also increases the risk of obesity, which is itself a significant driver of rising early-onset cancers [13].
Are Cancer Rates Really Rising?
While researchers are trying to identify causes, others are asking a different question:
What if the data isn't telling us what we think it is?
The South Korea Example
After 1999, thyroid cancer diagnoses surged in South Korea. But deeper analysis revealed that people were likely not developing more thyroid cancer—they were just being screened more often, leading to increased detection [14].
This raises an important point: are we seeing a true rise in cancer, or are we just getting better at spotting it?
What the Death Data Shows
One way to help answer this question is by looking at cancer-related deaths. If cancer is truly rising, then—unless treatments have drastically improved—more people should be dying.
But that is not what is happening in the U.S.
A recent JAMA study found that between 1990 and 2023, cancer deaths in people under 50 declined by 44%—from 25.5 to 14.2 per 100,000 [3].
Here is how some of the most common cancer death rates declined annually between 2014 and 2023:
- Brain cancer: ↓ 0.3% per year
- Breast cancer: ↓ 1.4% per year
- Leukemia: ↓ 2.3% per year
- Lung cancer: ↓ 5.7% per year [3]
This suggests medicine is detecting and treating many cancers more effectively, even if more people are being diagnosed.
The Colorectal Cancer Exception
But there is an alarming outlier: colorectal cancer.
Unlike other cancers, colorectal cancer death rates in people under 50 have risen by 1.1% annually since 2005, making it the leading cause of cancer death in this age group [3].
In this case, all the data—diagnosis rates, death rates, and the lack of routine screening in younger adults—suggests the increase is real, not just due to detection bias.
And there is reason to believe other GI cancers are truly increasing too.
Why This Rise Is Likely Real
- Most early-onset GI cancers are not routinely screened for in young adults. This includes pancreatic and stomach cancer [15].
- The fact that more young patients are presenting with symptoms—rather than being detected via screening—suggests a true rise in incidence.
Another reason to suspect a real increase: improved treatments may be masking rising incidence.
For example, pancreatic cancer 5-year survival rates rose from 16.5% in 2000 to 37.2% in 2016 [16]. Deaths may therefore be declining even as cases increase.
Global Perspective
The British Medical Journal analysis of 204 countries found a 28% rise in global early-onset cancer deaths from 1990 to 2019 [4].
Why the difference from the U.S.? Wealthier countries invest more in early detection and advanced treatment. In less developed countries, these safety nets are often missing.
The study included color-coded maps to illustrate this:
- In 2019, incidence rates were highest in North America, Western Europe, Australia, and New Zealand, and lowest in Africa and parts of the developing world [4].
- But when looking at death rates, the pattern flipped. Deaths were higher in regions with lower healthcare investment [4].
So while in wealthy nations like the U.S. it may look like cancer rates are not truly rising, globally the rise is real—and deadly.
The debate about whether more cases or more detection explains the data continues for many cancer types. But for colorectal cancer, there is no debate. It is genuinely rising, with serious consequences.
What to Do About This
1. Prioritize Diet
The modern Western diet—full of ultra-processed foods and red meat—is a known risk factor for colorectal cancer [17].
The evidence points to prioritizing:
- Fresh fruits
- Non-starchy vegetables
- Fiber-rich foods
Notably, dairy products have also been associated with lower colorectal cancer risk [17].
On fiber specifically, studies have found that each additional 10g of daily fiber intake is associated with a 10–17% reduction in colorectal cancer risk [17].
Excellent sources of fiber include:
- Lentils
- Beans
- Whole grains
- Seeds and nuts
- Certain fruits and vegetables
Note: For people with conditions like IBS or IBD (e.g., Crohn's disease), fiber recommendations will differ. Speaking with a healthcare provider is advisable.
2. Exercise—Even in Small Bites
Daily physical activity of moderate intensity for 30 minutes or more has been shown to reduce colorectal cancer risk [17].
Even without time for a full workout, "exercise snacks"—short bouts of movement distributed throughout the day—can provide meaningful long-term health benefits.
3. Screening and Early Detection
The American Cancer Society recommends that people at average risk start regular colorectal screening at age 45, and continue through age 75 if in good health [18].
There are now two main screening options:
- Visual exams, like colonoscopy
- Stool-based tests, which are highly sensitive and easy to do at home [18]
Stool-based tests are worth noting for their accessibility: they can be done at home without a procedure, making them a practical option for adults approaching or at the screening age. Those with a family history of colorectal cancer or other risk factors may wish to discuss earlier or more frequent screening with their healthcare provider.
4. Know the Red Flags
The following symptoms should not be ignored:
- Blood in the stool
- Abdominal pain
- Sudden changes in bowel habits
A recent analysis found that nearly 50% of people diagnosed with early-onset colorectal cancer had blood in the stool plus abdominal pain, and about 25% experienced altered bowel habits [19].
Important: These symptoms do not mean cancer is present. But they are signs that warrant prompt medical attention—early detection can be lifesaving.
References
2. https://www.businessinsider.com/rise-in-cancer-among-young-people-under-age-50-charts-2024-3
3. https://jamanetwork.com/journals/jama/article-abstract/2844189
4. https://bmjoncology.bmj.com/content/2/1/e000049
5. https://pmc.ncbi.nlm.nih.gov/articles/PMC10854951/
6. https://pmc.ncbi.nlm.nih.gov/articles/PMC11901572/#sec4-nutrients-17-00859
7. https://pmc.ncbi.nlm.nih.gov/articles/PMC7400286/
8. https://pubmed.ncbi.nlm.nih.gov/41528383/
9. https://www.mdpi.com/2305-6304/10/6/318
10. https://pubmed.ncbi.nlm.nih.gov/41521690/
11. https://pmc.ncbi.nlm.nih.gov/articles/PMC9972148/
12. https://www.sciencedirect.com/science/article/pii/S2095254621000466
13. https://pmc.ncbi.nlm.nih.gov/articles/PMC11467775/
14. https://www.bmj.com/content/355/bmj.i5745
15. https://pubmed.ncbi.nlm.nih.gov/40674064/
16. https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667%2824%2900156-7/fulltext
17. https://www.ncbi.nlm.nih.gov/books/NBK585999/
19. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2819248
