“Generation X and millennials are at an increased risk of developing certain cancers compared with older generations,” reports the Washington Post, “a shift that is probably due to generational changes in diet, lifestyle and environmental exposures, a large new study suggests.”

Researchers from the American Cancer analyzed data from more than 23.5 million patients who had been diagnosed with 34 types of cancer from 2000 to 2019 — and also studied mortality data that included 7 million deaths in the U.S. from 25 types of cancer among people ages 25 to 84. [The researchers reported] that cancer rates for 17 of the 34 most common cancers are increasing in progressively younger generations. The findings included:

• Cancers with the most significant increased risk are kidney, pancreatic and small intestine, which are two to three times as high for millennial men and women as baby boomers.
• Millennial women also are at higher risk of liver and bile duct cancers compared with baby boomers.
• Although the risk of getting cancer is rising, for most cancers, the risk of dying of the disease stabilized or declined among younger people. But mortality rates increased for gallbladder, colorectal, testicular and uterine cancers, as well as for liver cancer among younger women.

“It is a concern,” said Ahmedin Jemal, senior vice president of the American Cancer Society’s surveillance and health equity science department, who was the senior author of the study. If the current trend continues, the increased cancer and mortality rates among younger people may “halt or even reverse the progress that we have made in reducing cancer mortality over the past several decades,” he added.

While there is no clear explanation for the increased cancer rates among younger people, the researchers suggest that there may be several contributing factors, including rising obesity rates; altered microbiomes from unhealthy diets high in saturated fats, red meat and ultra-processed foods or antibiotic use; poor sleep; sedentary lifestyles; and environmental factors, including exposure to pollutants and carcinogenic chemicals.