Why are more adults under 50 diagnosed with cancer?

Since the 1990s, we’ve seen an increase in early onset cancer, defined as cancer diagnosed before the age of 50. This phenomenon has been noticed worldwide.

Brigham and Women’s Hospital researchers wanted to understand why so many adults are diagnosed with cancers, including colon, esophagus, kidney, and breast cancers, at such an early age. The results are alarming.

The team analyzed global data on 14 types of cancer that had increased in adults under 50 from 2000 to 2012. They combed through studies that looked at possible risk factors and reviewed literature that described the clinical and physical aspects of early-onset tumors. 

The experts determined that early life exposure to unhealthy lifestyle habits has increased throughout the decades. For example, children get less sleep than they did in previous decades.

“From our data, we observed something called the birth cohort effect. This effect shows that each successive group of people born at a later time (e.g., decade-later) have a higher risk of developing cancer later in life, likely due to risk factors they were exposed to at a young age,” noted study co-author Dr. Shuji Ogino. 

“We found that this risk is increasing with each generation. For instance, people born in 1960 experienced higher cancer risk before they turn 50 than people born in 1950 and we predict that this risk level will continue to climb in successive generations.”

Moreover, the researchers believe our gut microbiome is negatively affected by processed food, sugar, and alcohol consumption. 

“Among the 14 cancer types on the rise that we studied, eight were related to the digestive system. The food we eat feeds the microorganisms in our gut,” said study lead author Dr. Tomotaka Ugai. “Diet directly affects microbiome composition and eventually these changes can influence disease risk and outcomes.”

The experts plan to expand their research with a longitudinal cohort study that includes low- and middle-income nations, which they believe is the best way to achieve accurate results that can better inform future healthcare. 

The paper is published in  Nature Reviews Clinical Oncology.

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By Erin Moody , Earth.com Staff Writer