A new international study published in the journal Annals of Internal Medicine shows that worldwide, there will be an increase in obesity-related cancers in both younger and older adults. The reason is simple – the number of obese people in the world is constantly growing.
The research, in which scientists from the University of London (Imperial College London) participated, questions the previous assumptions that some types of tumors primarily affect younger adults, and fundamentally changes the view of the incidence of cancer in the 21st century.
The researchers analyzed data on cancer patients from 2003 to 2017 from 42 Asian countriesEurope, Africa, North and South America and Australia and Oceania. The data came from the GLOBOCAN database of the International Agency for Research on Cancer (IARC).
They focused on 13 types of cancer that, according to previous studies, more often affect younger adults – among them leukemia, cancer of the colon and rectum, stomach, breast, prostate, uterus, gallbladder, kidney, liver, esophagus, oral cavity, pancreas and thyroid gland.
Patients were divided into two age groups: younger adults (20–49 years) and older adults (50 years and older). Six types of cancer—leukemia, thyroid, breast, uterine, colon, and kidney—were shown to has a growing incidence in both age groups in almost three quarters of the monitored countries. These tumors are closely related to obesity. Researchers warn that obesity increases the risk of cancer across age groups, not just at a certain time of life.
According to experts, the accumulation of fatty tissue in the body can cause inflammation, change hormone levels, disrupt cell metabolism and create an environment that supports the formation of tumors. Cancer of the uterus and kidney had the most significant connection with obesity. Adipose tissue here functions not only as an energy store, but also as a hormone producer. If the balance of hormone secretion is disturbed, it can promote cell division and reduce the body’s ability to remove dead cells, thereby accelerating the risk of tumors, according to scientists.
Scientists also noted a decrease in the incidence of liver, oral cavity, esophagus and stomach cancer in the younger population, which they attribute to successful measures aimed at reducing smoking, alcohol consumption and viral hepatitis infections. Conversely, cancers of the digestive tract are increasing faster in younger adults than in older adults.
