A recent study by the American Cancer Society revealed that rates of obesity-related cancers in young people, ages 25 to 49, are rising. The study, which appeared in The Lancet Public Health, compared the incidence data for 30 different cancers between 1995 and 2014, and found that obesity-related cancers had much higher rates in younger populations than those cancers less closely associated with obesity.
The obesity-related cancers found to pose a higher risk for young adults include colorectal, endometrial, pancreatic, kidney, gallbladder and multiple myeloma. Alarmingly, the rates of some of these cancers in millennials are almost twice as high as the rates baby boomers experienced in their younger years.
Misagh Karimi, M.D., assistant clinical professor in the Department of Medical Oncology & Therapeutics Research at City of Hope, has seen this with his own patients.
“With colon cancer, for example, we’re seeing younger and younger patients. I have seen a lot of patients in the 40-to-50-year age range present with colon cancer, and when we do genetic testing, almost none of them have those genetic dispositions that we know about. So, while I’m not surprised by these findings, it’s still very unfortunate,” he said.
In thinking about why obesity is a major risk factor for so many cancers, there are several possible explanations.
“Many times, obesity causes low-level inflammation that over time causes other issues that may, over time, lead to malignancy. Obesity also causes some hormone levels to rise, like estrogen. And excess levels of estrogen have been linked to breast cancer in multiple studies. This is true of gynecologic cancers as well,” Karimi said.
“On the molecular level, insulin seems to be involved in this pathway, and type 2 diabetes is another risk factor for these cancers. So, there really aren’t just one or two reasons, there are several. And I’m sure there are other reasons we don’t even know about yet.”
Over the last 25 years, the cancer death rate has fallen, but the increase in obesity-related cancers in younger generations could stop that progress. To combat these stark statistics, widespread action in fighting the obesity epidemic on an individual and community level is vital.
Weight control would be beneficial to try to reduce this cancer risk. What you do, in terms of your lifestyle — healthy eating, exercise — it does make a difference. With our patients, we have this discussion all the time. Exercising is important, but so is the food you consume,” Karimi explained.
“A lot of times, weight loss comes as a result of small changes. For example, when grocery shopping, we tell patients to ignore the middle section of the store and shop on the periphery for unprocessed foods. We also encourage preparing food at home and eating out less. By changing just these things, we’ve seen patients lose weight."
Even with the study’s findings, Karimi remains hopeful for the future if we can raise awareness and work to help people improve their lifestyle habits.
“Obesity is something we need to work on. It’s an epidemic that we need to pay attention to, but I believe we can tackle this.”