More than 6 in 10 adults in the United States drink sugar-sweetened beverages on a daily basis. For older women, that might mean a higher risk of liver cancer and death from chronic liver disease, a new study finds.
The report, published on Tuesday in the medical journal JAMA, tracked the beverage choices of nearly 100,000 women between the ages of 50 and 79 across the United States and looked at their health outcomes over two decades. Compared with women who consumed fewer sugar-sweetened beverages less frequently, those who drank sugary beverages every day faced higher rates of liver cancer and death from chronic liver disease.
Throughout the study, participants reported how often they consumed sweetened soft drinks and fruit drinks on a scale from “never or less than once per month” to “6 or more per day.” Researchers also looked at the number of those women who were diagnosed with liver cancer or died from chronic liver disease across a study period of, on average, nearly 21 years.
The participants were part of the Women’s Health Initiative, a long-term national study funded by the National Heart, Lung, and Blood Institute that began in the late 1990s. Approximately 7% of the women in the study drank sugary-sweetened beverages daily, the report said; over 13% consumed artificially sweetened drinks each day.
The researchers found that women who drank at least one sugar-sweetened beverage a day were 1.75 times as likely to be diagnosed with liver cancer compared with those who consumed three or fewer sugar-sweetened beverages per month. Daily drinkers were nearly 2.5 times as likely to die from chronic liver disease, as well.
However, women who drank beverages that were artificially sweetened did not have a much higher risk of those liver problems, regardless of whether they consumed the drinks daily or not.
“I think this provides clearly another piece of evidence of the potential negative effects on our health of consuming sugar-sweetened beverages,” said Dr. Karina Lora, an assistant professor of exercise and nutrition sciences at George Washington University who was not involved in the study.
“It provides another clue that a good diet or good dietary pattern is important even much more as we age.”
Over 56,000 people die from chronic liver disease each year in the United States, according to the US Centers for Disease Control and Prevention, making it the nation’s ninth leading cause of death. About 11,000 women get liver cancer in the United States, and 9,000 die from it each year.
While the findings highlight a potential link between liver conditions and regularly drinking sugary beverages, the study doesn’t show a cause-and-effect relationship between sugar-sweetened drinks and liver problems. Nor can the researchers pinpoint how sugar might increase the risk for liver conditions on a biological level, the report said.
And while Lora believes that the study has important findings, she also pointed out that the vast majority of participants were White women, with Black women as a distant second. Hispanic women made up a small fraction of the participants, even though liver conditions like fatty liver disease and liver cancer are more prevalent in Hispanic communities.
“It will be interesting in the future to investigate these different subsets and cohorts,” Lora said. “If you look at that group, non-alcoholic fatty liver disease and even liver cancer is very prevalent.”
Experts also pointed out that the researchers also only recorded participants’ drink habits at the start of the study, in the early 1990s, and once more three years later. Their drink habits — and the amount of sugar in soft drinks — likely changed over those two decades and may have altered their risk of developing liver cancer and chronic liver disease.
Despite some limitations, experts agree that the general message is clear: Be careful when drinking sugar-sweetened beverages.
According to study authors Longgang Zhao and Xuehong Zhang, a postdoctoral research fellow and associate professor of medicine, respectively, at Brigham and Women’s Hospital and Harvard Medical School, consumption of sugar-sweetened beverages remains high in the United States. If the drinks are risk factors for liver cancer and chronic liver disease, like their data suggest, cutting down on sugar-sweetened beverages could be “a public health strategy to reduce liver disease burden,” they wrote in an email to CNN.
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“We know from a body of evidence that it is worth thinking twice before choosing to drink sugar-sweetened beverages every day,” Dr. Pauline Emmett, senior research fellow at the University of Bristol, told the Science Media Center in the UK.
Lora agreed that consumers should keep the possible harms of sugary beverages in mind as they make decisions about their health, but urged the public to avoid panicking.
“Don’t freak out,” she warned. “Nobody’s saying don’t consume [sugar-sweetened beverages]. You can consume it, but be aware.”
Her best advice? Drink water. But if consumers insist on sugar-sweetened drinks, Lora added, they should do so sparingly.
“Moderation is important,” Lora said. “If you want to enjoy some of these beverages, enjoy it — but not frequently.”
