For most of us, beef and a glass of milk feel like everyday comfort food. Burgers on the grill, a latte on the way to work, yogurt in a lunchbox. Yet Nobel Prize-winning virologist Harald zur Hausen spent his final years arguing that products from cattle could quietly raise the risk of serious disease, especially colon cancer.
He called beef consumption “a high risk factor” for colorectal cancer and urged extra caution with cow’s milk during infancy.
Zur Hausen pointed to a striking pattern. Countries where beef from dairy cattle is eaten often such as Japan and South Korea show high colorectal cancer rates. India, where the cow is sacred and beef consumption is minimal, sits at the opposite end of the scale.
He also floated a tougher question. Could something in cattle products help explain not only colon and breast cancers but some neurodegenerative diseases like multiple sclerosis and Parkinson’s?
In parallel, global health agencies have been sounding their own alarms about red and processed meat. The World Health Organization and its cancer arm, the International Agency for Research on Cancer, classify processed meat as carcinogenic to humans and red meat as probably carcinogenic, mainly for colorectal cancer.
Each small daily portion of processed meat is linked to a measurable increase in bowel cancer risk. Mechanisms include heme iron, which can foster cancer-causing compounds in the colon, and chemicals formed when meat is grilled or fried at very high temperatures.
Zur Hausen tried to connect these dots with a bold hypothesis. Working at the German Cancer Research Center, his team described tiny, circular DNA molecules in beef and cow’s milk that they called bovine meat and milk factors, suggesting these infections might promote chronic inflammation in tissues such as the colon and breast.
Some studies have since detected these molecules in human colon tissue. Others tie early life exposure to dairy cattle products to higher rates of colon and breast cancer decades later.
Regulators, however, are being cautious. A recent joint opinion from Germany’s food safety authorities concluded that current data do not prove these DNA elements are new pathogens or that they actually harm consumers. They even state that meat and cow’s milk can remain part of infant diets while research continues.
So where does that leave your steak dinner? Most experts converge on a down-to-earth message. Keep processed meat occasional, keep red meat moderate, favor plenty of plants, fish, and poultry, and avoid regularly charring meat on the grill.
That approach respects long term cancer data while scientists keep arguing over the finer points of viruses, DNA circles, and who is really at risk.
The official reassessment of bovine meat and milk factors was published by the German Federal Institute for Risk Assessment.
