Why Do Millennials Have a Higher Cancer Risk? How Food, Alcohol, Sleep, and Stress Contribute to Cancer Risk: Our "Normal Life" is Damaging Our DNA

The commentary published in The Independent on October 29 explains the reality that millennials (born between 1981 and 1995) face a higher cancer risk than their parents' generation, attributing it not to genetics but to the accumulation of lifestyle and environmental factors. Early-onset cancer in those under 50 increased by 79% globally from 1990 to 2019, with deaths rising by 28%. The article describes this as a "new epidemic," illustrating how everyday habits like diet, alcohol consumption, sleep, stress, and self-medication contribute to DNA damage.The Independent

What's Happening: Trends Told by Numbers

This "79% increase" aligns with a global analysis by BMJ Oncology, which reported a 79.1% rise in early-onset cancer incidence and a 27.7% increase in deaths between 1990 and 2019. Additionally, summaries from the NCI and the American Cancer Society indicate that cancers such as colorectal, breast, uterine, and kidney are increasing among those under 50, with a particularly noticeable rise in those in their 20s.bmjoncology.bmj.com

"Everyday" Over "Genetics": The Contribution of Lifestyle Factors

The Independent states that "about 80% of cancers are sporadic (non-genetic)," explaining that external factors such as diet, air, exercise, sleep, and stress accumulate damage to DNA. This implies that a significant portion can be prevented through "modification of environment and behavior."The Independent

Diet and Gut Environment: Ultra-Processed Foods, Obesity, and Gut Bacteria

Childhood obesity, which accelerated since the 1980s, is said to elevate the risk of colorectal and breast cancer in adulthood through inflammation and hormonal changes. A decrease in gut bacterial diversity and an increase in inflammatory metabolites are linked to gastrointestinal diseases in youth, and recent studies suggest that early exposure to the toxin colibactin produced by E. coli may be associated with mutational signatures of early-onset colorectal cancer.The Independent

Alcohol: Revising the Myth of "Moderate Drinking is Good for Health"

The WHO and IARC classify alcohol as a human carcinogen (Group 1), stating that "no safe level can be set from a cancer prevention perspective." The risk of DNA damage tends to increase as drinking patterns shift from small amounts frequently to "occasional heavy drinking." Recent studies have also detected PFAS (forever chemicals) in beer.World Health Organization

What’s in a Drink: PFAS and Environmental Chemicals

A study published in Environmental Science & Technology in 2025 detected PFAS in many beers across the United States, showing a correlation with local water supply contamination. PFAS are chemicals associated with increased risks of kidney and testicular cancer. Even trace exposure through beverages and food can raise "total exposure."ACS Publications

A Society That Can't Sleep: Disruption of Circadian Rhythms and Melatonin

The light from smartphones and night shifts disrupt the secretion of the sleep hormone melatonin and the body's internal clock. The IARC evaluates "night shift work" as "probably carcinogenic (2A)." Mechanistically, circadian rhythm disruption is shown to affect DNA repair and immune surveillance.

Invisible Fire: Chronic Stress

Chronically high cortisol levels alter the tumor microenvironment through inflammation and immune suppression. Reviews and mouse studies show that stress can promote metastasis through biological responses such as NETs formation, and epidemiological reports increasingly link psychological stress with cancer incidence and mortality.

The Pitfall of "Easy Medication": Self-Medication, Antacids, and Antibiotics

Medications often used long-term based on self-judgment can become "noise" that accumulates risk. Paracetamol (acetaminophen) is known for its hepatotoxicity, with emerging studies suggesting a link to liver cancer (though findings are still uncertain). Meanwhile, meta-analyses increasingly associate long-term use of proton pump inhibitors (PPIs) with an increased risk of gastric cancer. Repeated use of antibiotics alters the gut microbiota, with reports of correlations with colorectal cancer risk by site. This is an area requiring careful medical management.

The "Reality" of 2050: 35 Million New Cancer Cases

The WHO and IARC predict 35 million new cancer cases by 2050, a 77% increase compared to 2022. As long as exposures to tobacco, alcohol, obesity, and air pollution continue, the curve will remain upward. The increase among younger generations is a harbinger of this trend.World Health Organization

Reactions on Social Media: Anxiety, Doubts, and Sharing Experiences

Three voices intersect on social media: (1) Anxiety, such as "It's scary that cancer is increasing among people in their 30s," (2) Skepticism, like "Isn't it just that diagnoses have increased?" and (3) Sharing personal or family experiences with cancer. Multiple threads on Reddit cite obesity, alcohol consumption, ultra-processed foods, and microplastics as causes, along with observations that "while deaths are decreasing, early detection has also improved."Reddit

Practical Actions You Can Take Now (Millennial Edition)

1. Manage Alcohol by "Weekly Total": Create alcohol-free days and avoid binge drinking (there is no safe range from a cancer prevention perspective).World Health Organization

2. Optimize Diet to "Protect the Gut": Favor unprocessed foods, increase fiber and fermented foods, and reduce the frequency of ultra-processed foods.

3. Sleep Hygiene: Cut out blue light 1–2 hours before bed. Night workers should use blackout curtains, maintain regularity, and expose themselves to morning light.

4. Make Stress "Visible": Engage in 150 minutes of exercise per week, practice breathing techniques, short meditation, and seek interpersonal support. Consult a professional if needed.

5. Stop Self-Medication and Adhere to Prescribed "Duration": Review indiscriminate use of PPIs and antibiotics.

6. Improve the Quality of Water and a Drink: Consider PFAS-reducing filters at home. Pay attention to water source information for craft beers.PMC

7. Know the Screening Age: Consult "ahead of age" if you have a family history or symptoms.

8. Create a Health Culture at Work: Designing systems to reduce consecutive night shifts and overtime is more effective than individual efforts.

Quick Answers to Common Questions

• "Is Red Wine Good for Health?" ─ From a cancer prevention perspectiveNo. There is "no safe amount" overall.World Health Organization

• "Is the Increase in Young Cancer Due to More Testing?" ─ Detection impacts exist, but actualincidence increases have been confirmed in multiple cancer types.

• "Is the Cause Genetic?" ─ Hereditary cases are a minority. Lifestyle and environmental contributions are significant.The Independent

Conclusion

The increase in cancer among millennials is a "complex pollution" that cannot be explained by a single cause. Drinking habits, eating habits, sleeping habits, working habits, self-medication, and environmental chemicals—the "1% accumulation" of daily life changes the curve. Our future risk begins to shift by changing this week's shopping list, next week's work shift, and next month's health checkup appointment.The Independent

Key Articles and Studies Referenced
・The Independent (2025/10/29) "The Real Reason Millennials Have Higher Cancer Rates Than Their Parents" The Independent
・BMJ Oncology: 79% Increase in Early-Onset Cancer from 1990–2019 Analysis bmjoncology.bmj.com
・WHO/IARC: 35 Million Cases Predicted for 2050 / Alcohol is Carcinogenic with No Safe Level World Health Organization
・PFAS in Beer (Environmental Science & Technology, 2025) ACS Publications
・IARC: Night Shift Work is "Probably Carcinogenic (2A)"
・NCI and Others: Overview of Cancers Increasing Among the Young
・Reddit: Examples of Representative Reactions on Social Media