Nearly a quarter of the 18 million cancer cases diagnosed globally each year could be preventable through improved nutrition, according to experts at the Harvard T.H. Chan School of Public Health.
Research spanning decades, including the ongoing Health Professionals Follow-up Study – a nearly 40-year investigation tracking over 50,000 male health professionals – has illuminated the impact of diet and lifestyle on cancer risk. The study, supported by the National Institutes of Health (NIH), leverages the detailed health knowledge and willingness to participate of health professionals to analyze the effects of various factors on disease development.
Dr. Andrew T. Chan, professor of immunology and infectious diseases at Harvard Chan School, delivered the 2025 Arthur Schatzkin Memorial Lecture at the National Cancer Institute (NCI) in September, focusing on the role of diet and the gut microbiome in colorectal cancer risk. His research identified strain-level associations within the gut microbiome linked to the disease, with some species also implicated in cardiovascular and immune-mediated illnesses, suggesting a potential pro-inflammatory role.
Dr. Chan also described the development of dietary scores related to gut microbiome composition and colorectal cancer risk. He is co-leading the PROSPECT Study, a Cancer Grand Challenge initiative, which aims to uncover the underlying causes of early-onset colorectal cancer through an interdisciplinary approach encompassing epidemiology, laboratory research, and clinical trials.
Early studies consistently demonstrated a link between fruit and vegetable consumption and cancer protection. The Harvard Chan School of Public Health emphasizes the importance of incorporating these foods into a diet aimed at lowering the risk of chronic illnesses, including cancer.
Federal funding continues to be crucial for this research. For over a century, Harvard T.H. Chan School of Public Health faculty have conducted research leading to vaccines, treatments, and policies that have saved millions of lives, both in the U.S. And internationally.
