A new analysis reveals that Generation Z may face an even greater risk of developing cancer than millennials, as lifestyle factors drive a global surge in early-onset cancers. Between 1990 and 2019, cases of cancer among people under 50 increased by 79% worldwide, with mortality rising by 28%.
Experts attribute around 80% of cancers to external factors such as diet, alcohol consumption, sleep patterns, and exposure to harmful substances, rather than hereditary mutations. Childhood obesity, which began to skyrocket in the 1980s, is a key factor: in 2022, over 390 million children aged 5-19 were overweight, with 160 million classified as obese. Obesity is linked to insulin resistance, chronic inflammation, and hormonal changes that increase the risk of colorectal, breast, and endometrial cancers. A meta-analysis found that high BMI in early life raises colorectal cancer risk by 39% in men and 19% in women.
Dietary changes have also altered gut microbiota, with ultra-processed foods reducing bacterial diversity and promoting pro-inflammatory metabolites. This contributes to gastrointestinal issues like irritable bowel syndrome, which are common among younger generations. Alcohol consumption patterns differ: while baby boomers drink more regularly, millennials and Gen Z engage in more binge drinking, which carries significant risks. The International Agency for Research on Cancer classifies alcohol as a Group 1 carcinogen, and a recent study found that many beers contain perfluoroalkyl substances (PFAS), linked to testicular and kidney cancer.
Sleep deprivation is another major concern. Surveys show that millennials and Gen Z get 30-45 minutes less sleep per night than baby boomers, largely due to screen exposure. This disrupts melatonin release, impairing DNA repair and increasing cancer risk. Disrupted circadian rhythms also interfere with genes essential for DNA repair, allowing mutations to accumulate over time.
