Daily consumption of sodas and other sweetened drinks may be linked to an increased risk of developing colorectal cancer before age 50, according to a study published May 6 in the journal Gut.
Researchers from the Harvard T.H. Chan School of Public Health and Washington University looked at data from 95,464 women from the Nurses Health II study between 1991 and 2015. Participants filled out surveys every four years tracking their consumption of various foods, including sugary beverages like soda, sports drinks, fruit drinks other than juice, and energy drinks.
They found that women who drank two or more eight-ounce servings of sweet beverages a day were twice as likely to develop colon cancer before age 50 than their peers who drank less than a serving per week.
The increased risk could start in the teenage years, too — the study found that for youth aged 13 to 18, each daily serving of sweet drinks was linked to a 32% higher risk of eventually developing colon cancer before age 50.
Because of the increase in early-onset colon cancer, the average age of diagnosis has dropped from 72 to 66 years old, and cases tend to be more advanced, according to Yin Cao, senior author of the study and associate professor of surgery at Washington University.
"Colorectal cancer in younger adults remains relatively rare, but the fact that the rates have been increasing over the past three decades — and we don't understand why — is a major public health concern and a priority in cancer prevention," Cao said in a news release.
Researchers adjusted for other lifestyle factors such as smoking, drinking alcohol, low dietary fiber, and high consumption of red and processed meat. One caveat of this research, however, is that participants were mainly white female nurses, so it's not clear if the data would differ for other populations. The study also found relatively low rates of colorectal cancer: only 109 participants developed the disease in 24 years of follow up.
Unhealthy diets may be linked to a raise in colorectal cancer among younger people
These findings may help researchers understand why colorectal cancer has become more common in people under age 50.
"In past work, we have shown that poor diet quality was associated with increased risk of early-onset colorectal cancer precursors, but we have not previously examined specific nutrients or foods," Cao said in the news release.
Previous research found that 12% of the US population consumes three or more servings of sweetened drinks per day. These rates have declined in recent years, studies show.
Encouraging the population to swap out sugary drinks for antioxidant-rich beverages like coffee or tea, unsweetened drinks like milk, or even plain water, could be an important step in public health measures to prevent cancer, the researchers concluded.
