How did researchers determine the benefits of yogurt against colorectal cancer?

Harvard Medical School researchers conducted an extensive longitudinal study involving 130,000 participants who were followed for 30-40 years. During this period, they documented and analyzed nearly all colorectal cancer incidents that occurred within the study cohort. This comprehensive approach allowed researchers to establish reliable connections between yogurt consumption and colorectal cancer risk, particularly for aggressive forms of the disease. The long-term nature of the study and large sample size provided robust statistical data to determine yogurt's protective benefits against colorectal cancer.