Adults who drink two or more daily sugar-sweetened beverages may be doubling their risk for developing bowel cancer before they turn 50 years old, according to a study published Thursday by the journal Gut.
Furthermore, each additional serving eaten daily is associated with a 16% increased risk of the disease, according to the study.
Since the report focused specifically on cancer risk in women, the researchers claim the results illustrate the possible risks they pose from sugary drink intake.
“Our findings have added another reason to avoid sugar-sweetened beverages and also provided preliminary support that intake may contribute to the rising incidence of colorectal cancer under age 50, a growing concern in cancer prevention,” study co-author Dr. Yin Cao told UPI in an email.
The findings “also suggest that reducing sugar-sweetened beverage intake and replacing [them] with other healthier beverages, in particular milk, would be a better and wiser choice for long-term health,” said Cao, an associate professor of surgery at Washington University School of Medicine in St. Louis.
Heavy consumption of sugar-sweetened beverages already has been linked to increased risk for obesity and type 2 diabetes, a disease caused by the body’s inability to process sugar.
Sugar-sweetened foods, such as soft drinks, fruit-flavored drinks, and sports and energy drinks, are the leading source of added sugar in American diets, according to the researchers, with 12 percent of the population drinking more than three servings (8 fluid ounces each) everyday.
At the same time, they reported that cases of bowel cancer diagnosed before the age of 50, known as early onset colorectal cancer, have been growing in the United States for nearly 20 years.
According to the researchers, adults born around 1990 have a two-fold higher risk of colon cancer and a four-fold higher risk of rectal cancer than adults born around 1950.
Given these parallel trends, they theorized that intake of these drinks also may have an association with bowel cancer, given that they are processed through the digestive tract.
Cao and her colleagues examined data from more than 95,000 participants in the Nurses’ Health Survey II, an ongoing surveillance study of 116,429 female registered nurses in the United States, to investigate this possible connection.
Starting in 1991, the women revealed what they consumed and drank by filling out diet frequency questionnaires every four years.
Furthermore, over 41,000 of them commented on what and how much they drink between the ages of 13 and 18.
Participants also supplied information on potentially influential factors, including family history of bowel cancer, lifestyle, regular use of aspirin or non-steroidal anti-inflammatory drugs and vitamin supplements, all of which have been linked with increased bowel cancer risk.
After the study tracked participants’ health for an average of 24 years, 109 women developed bowel cancer before age 50.
Compared with those who drank fewer than one sugar-sweetened beverage serving per week, women who consumed two or more every day were more than twice as likely to be diagnosed with bowel cancer, the researchers said.
Among the participants who reported on their teen patterns of consumption, each daily serving was associated with a 32% higher risk for subsequently developing the disease before age 50.
Substituting chemically sweetened beverages, chocolate, or semi-skimmed or whole milk for sugar-sweetened beverages was associated with a 17 percent to 36 percent lower risk of early-onset bowel cancer.
Cao believes that further research is needed to determine the explanations for the connection between sugar-sweetened drinks and cancer risk.
However, she believes that the advent of obesity and type 2 diabetes related to high consumption can play a role in the development of cancer.
According to Cao, these beverages can also have a harmful effect on the activity of the human digestive system, and can stimulate the growth of cancer.
“Higher sugar-sweetened beverage intake [is] associated with obesity, which has been previously linked to risk of early-onset colorectal cancer,” Cao said.
“A recent experimental study also suggests that high-fructose corn syrup, the primary sweetener [in these drinks], may exert influence on colon tumor growth,” she said.