Longitudinal body mass index and cancer risk: A cohort study of 2.6 million adults, published in Nature Communications, has found that overweight and obesity during early adulthood (between ages 18–40 years) could be linked with up to 18 cancers, with some of these cancers not previously associated with weight as a risk factor.
The results of the study found the longer the length of time, the greater the degree, and the younger the age of overweight and obesity, the higher the associated risk of developing 18 different cancers.
The study of 2,645,885 individuals looked at people’s body mass index (BMI) status across their lifetimes instead of focusing on one BMI measurement.
Researchers led it by the Institut d’ investigació en Atenció Primària de Salut Jordi Gol (IDIAPJGol) in collaboration with the International Agency for Research on Cancer (IARC). They funded by the Wereld Kanker Onderzoek Fonds (WKOF).
Previous evidence from the World Cancer Research Fund and others has linked overweight and obesity to at least 13 cancers. Some new cancers the study found could be linked to weight include leukaemia, non-Hodgkin lymphoma, and bladder cancers among people who have never smoked.
Andrea Pistillo, one of the study’s lead authors, comments: “In this study, we used advanced methodologies to retrieve missing information on BMI from participants. After nine years of follow-up, 225,396 participants were diagnosed with cancer.
“We found that apart from BMI at baseline, other BMI-derived indicators such as duration, degree and age of onset of overweight and obesity were associated with the risk of up to 18 types of cancers.
“So far, only 13 types of cancers were associated with high BMI. One of the study’s objectives was to assess whether life-course adiposity-related exposures are more relevant to cancer risk factors than only one BMI measurement.”
Dr Heinz Freisling from IARC and one of the study’s co-leaders, says: “The results of our study support a re-evaluation of the cancer burden associated with overweight and obese, which currently is likely underestimated.”
Dr Talita Duarte-Sallés, the principal investigator of the project at IDIAPJGol, further emphasised the public health implications of the study findings: “These compelling results support the implementation of primary care-based strategies for cancer prevention, with a strong focus on preventing and reducing early overweight and obesity.
“This pioneering research marks a significant milestone in understanding the intricate relationship between overweight/obesity and cancer risk. With these findings, the global Premsa IDIAPJGol: Xavier Codony community has a powerful new tool to shape targeted interventions, develop effective prevention strategies, and ultimately significantly impact cancer outcomes worldwide.”
Dr Panagiota Mitrou, director of research, policy, and innovation at the World Cancer Research Fund, said: “This large study has future public health implications since additional cancers, such as leukaemia and non-Hodgkin lymphoma, be linked with overweight and obesity.
“Our own evidence shows that maintaining a healthy weight throughout life is one of the most important things people can do to reduce their cancer risk, and early prevention in adulthood is key.”