The more sugar-sweetened beverages people consume, the greater their risk of dying early, particularly from heart disease but also from cancer, according to a study published Monday in the journal Circulation.
The study also found an association between artificially sweetened beverages and premature death, although the risk was lower.
“Our results provide further support to limit intake of [sugar-sweetened beverages] and to replace them with other beverages, preferably water, to improve overall health and longevity,” said Vasanti Malik, the study’s lead author and a research scientist at Harvard University, in a released statement.
Limiting sugary beverages is apparently a challenge for many Americans. Although the consumption of such beverages in the United States has declined since 2000, surveys have shown a slight rebound in recent years, in large part due to increased sales of energy drinks and sports drinks.
As background information in the study points out, sugar-sweetened beverages have been previously linked to weight gain and a higher risk of type 2 diabetes, heart disease and stroke. But few studies have looked specifically to see if there is a link with early death.
This current study is meant to help fill that research gap.
Gathering the data
For the study, Malik and her colleagues used data from two large, ongoing U.S. studies: the Nurses’ Health Study, which enrolled 121,700 women aged 30 to 55 starting in 1976, and the Health Professionals Follow-up Study, which enrolled 51,529 men aged 40 to 75 starting in 1986.
The participants in these studies filled out detailed questionnaires every four years about their lifestyle (such as diet and exercise habits) and health status (what illnesses they had).
Malik and her co-authors excluded people from their own study who had diabetes, heart disease or cancer at the time they were enrolled in the larger studies. They also excluded people who left too many blank answers — particularly regarding diet — on their questionnaires.
In the end, their analysis included 80,647 women and 37,716 men.
The questionnaires asked people how often they consumed various foods and beverages. The sugary beverage category included caffeinated colas, caffeine-free colas, other carbonated sugar-sweetened beverages and non-carbonated sugary drinks (such as lemonade and fruit drinks). It did not include fruit juices.
Malik and her colleagues followed the women for an average of 34 years and the men for an average of 28 years. During that time, 23,432 of the women died, including 4,139 from heart disease and 8,318 from cancer. Among the men, 13,004 died, including 3,757 from heart disease and 4,062 from cancer.
After taking into account major known risk factors for early death (such as smoking, physical activity and weight), the researchers found that the more sugary drinks that people consumed, the greater their risk of dying early from any cause.
Specifically, the researchers compared the consumption of less than one sugary drink per month with other amounts. Here’s what they found:
- One to four sugary drinks per month raised the risk of early death by 1 percent.
- Two to six per week increased the risk by 6 percent.
- One to two per day increased the risk by 14 percent.
- Two or more per increased the risk by 21 percent.
The analysis found a particularly strong link between drinking sugar-sweetened beverages and an increased risk of early death from heart disease. People who consumed two or more sugary drinks daily had a 32 percent higher risk of dying from heart disease during the study than people who consumed less than one drink per month.
The study found a much smaller link between drinking artificially sweetened beverages and early death. Those drinks were associated with a 4 percent increased risk from any cause and a 13 percent increased risk from heart disease — but only among people who drank more than two servings a day.
Limitations and implications
The study is observational, which means it can’t prove that certain beverages cause early death. Other factors not adjusted for in the study (such as genetics) may have influenced the results.
In addition, the participants self-reported their food choices — and they did so only every four years. The reports may not have been totally accurate.
The participants were also all health professionals and mostly white. The applicability of the findings to more diverse populations is therefore unknown.
Still, there is plenty of other research on the negative health effects of consuming added sugar, particularly from soft drinks and other sugary beverages.
“These findings are consistent with the known adverse effects of high sugar intake on metabolic risk factors and the strong evidence that drinking sugar-sweetened beverages increases the risk of type 2 diabetes, itself a major risk factor for premature death,” says Dr. Walter Willett, one of the study’s authors and a professor of epidemiology and nutrition at Harvard, in a released statement.
“The results also provide further support for policies to limit marketing of sugary beverages to children and adolescents and for implementing soda taxes because the current price of sugary beverages does not include the high costs of treating the consequences,” he adds.
The research was funded by a grant from the National Institutes of Health. As they note in their paper, both Malik and Dr. Willett have provided pro bono support to organizations involved in litigation against the manufacturers of sugar-sweetened beverages.
FMI: The study can be read in full on Circulation’s website.