Obesity may raise risk of blood cancer by over 70%: Study

Researchers find that obesity may increase the risk of developing multiple myeloma -- a blood cancer of the plasma cells -- by more than 70 per cent.

Smoking habits and exercise may also impact one’s likelihood of developing multiple myeloma, said the team from Massachusetts General Hospital in the US.

The research published in Blood Advances revealed that individuals with obesity are more likely to have monoclonal gammopathy of undetermined significance (MGUS) -- a benign blood condition that often precedes multiple myeloma.

“While significant advancements have been made in therapeutics for multiple myeloma, it remains an incurable disease, often diagnosed after patients have already experienced end-organ damage,” explained David Lee, from Massachusetts General Hospital.

The team enrolled 2,628 individuals from across the US who were at elevated risk of developing multiple myeloma, based on self-identified race and family history of hematologic malignancies, between February 2019 and March 2022.

They found that being obese was associated with 73 per cent higher odds of having MGUS, compared to individuals with normal weights. This association remained unchanged when accounting for physical activity.

However, highly active individuals (defined as doing the equivalent of running or jogging 45-60 minutes per day or more) were less likely to have MGUS even after adjusting for BMI class, whereas those who reported heavy smoking and short sleep were more likely to also have detectable levels of MGUS.

MGUS, characterised by an abnormal protein produced by plasma cells, is a known precursor to multiple myeloma. Most people with MGUS exhibit no significant symptoms and are not immediately ill. Rather, the presence of MGUS serves as a warning to monitor for the potential development of more critical conditions, like multiple myeloma, that MGUS can turn into.

"These results guide our future research in understanding the influence of modifiable risk factors, such as weight, exercise, and smoking, on cancer risk," explained Lee.

"Before we can develop effective preventative health strategies to lower the risk of serious diseases like multiple myeloma, we first need to better understand the relationship between MGUS and potentially modifiable risk factors like obesity.”