For years, doctors have sounded the alarm over the link between cancer and obesity.
Being overweight or obese raises the risk of developing several different types of cancer, including breast, bowel, kidney and pancreatic.
In all, 13 types of the disease were previously known to be associated with overweight body types — but now, that number has climbed to 18 different cancers.
And the risk of developing cancer begin when people are young — between the ages 18 and 40.
“The results of our study support a re-evaluation of the cancer burden associated with overweight and obesity, which currently is likely underestimated,” said Dr. Heinz Freisling, co-author of the study, as quoted in the Independent.
The researchers looked at the electronic health records of more than 2.6 million people in Catalonia, Spain. The people were 40 years or older in 2009 and were then free of cancer.
But by 2018 — just nine years later — over 225,000 of the study participants had been diagnosed with cancer.
The researchers also sorted the data by including decades of the participants’ health records showing a body mass index of 25 or greater, which indicates a person may be overweight or obese.
The results of the study, published in Nature Communications, revealed that having a BMI of 25 or greater led to a greater risk of developing 18 different types of cancer.
Specifically, the researchers found that those who were overweight in early adulthood — ages 18 to 40 — had an increased risk of cancer.
And people who were overweight or obese for a longer period of time also had a higher risk of developing cancer. Finally, those with a much higher degree of obesity in their youth had a greater risk of cancer.
“Our findings seem to indicate that longer exposures to overweight and obesity (with or without accounting for the degree of overweight and obesity), as well as developing overweight and obesity at younger ages in early adulthood might increase cancer risk,” the researchers wrote.
The study adds to a large and growing body of medical evidence showing the long-term risks of childhood obesity, including cognitive function and brain structure.
The additional types of cancer the researchers linked to overweight or obesity include leukemia, non-Hodgkin lymphoma, head and neck cancers and bladder cancer.
The 13 cancers previously associated with being overweight or obese are adenocarcinoma of the esophagus, breast (in women who have gone through menopause), colon and rectum, uterus, gallbladder, upper stomach, kidney, liver, ovaries, pancreas, thyroid, meningioma (a type of brain cancer) and multiple myeloma, according to the Centers for Disease Control and Prevention.
“This large study has future public health implications since additional cancers, such as leukemia and non-Hodgkin lymphoma, have 1688671198 been shown to be linked with overweight and obesity,” said Dr. Panagiota Mitrou, director of research, policy and innovation at the World Cancer Research Fund.
“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.”