The results of a study headed by researchers at the Harvard T. H. Chan School of Public Health have suggested that the more sugar-sweetened beverages (SSB) people drink as adults, the greater their risk of death, primarily from cardiovascular disease (CVD), but also to a lesser extent from cancer. The findings from an analysis of two large prospective cohorts of adult men and women indicated that the link between SSB consumption and increased mortality risk was stronger in women than in men. The results also found that while moderate consumption of artificially sweetened beverage (ASB) as an alternative to SSBs did lower the risk of death slightly, drinking more than four ASBs per day was also associated with a higher risk of death in women.
“Our results provide further support to limit intake of SSBs and to replace them with other beverages, preferably water, to improve overall health and longevity,” said study lead Vasanti Malik, ScD, a research scientist in the department of nutrition. “Diet soda may be used to help frequent consumers of sugary drinks cut back their consumption, but water is the best and healthiest choice.”
Findings from the research are reported today in Circulation, in a paper titled, “Long-term consumption of sugar-sweetened and artificially sweetened beverages and risk of mortality in U.S. adults.”
SSBs are the largest source of added sugar in the U.S. diet, the authors wrote. Such beverages include carbonated and noncarbonated soft drinks, and fruit and sports drinks that contain added high fructose corn syrup, sucrose, or fruit juice concentrates. A typical SSB serving of a soda may contain 35–37.5 g of sugar, the team further pointed out, and adults in the U.S. consume on average 145 calories per day from SSBs, which is about 6.5% of their energy intake. In younger adults, SSBs may contribute as much as 8% up to 9.3% of daily calorie intake, and these levels “nearly exceed dietary recommendations for consuming no more than 10% of total energy from all added sugar.”
Prior epidemiological studies have linked SSBs with weight gain and a higher risk of diseases including type 2 diabetes, coronary heart disease, and stroke but, as the scientists commented, “to date, few studies have examined the association between SSB intake and mortality.” And while ASBs are often suggested as alternatives to SSBs, there is little known about the long-term effects of these drinks on health.
To investigate this in more detail, the authors turned to two large, ongoing prospective cohort studies. They analyzed questionnaire-reported dietary and other lifestyle data from 80,647 women (aged 30–55 years) in the Nurses’ Health Study (NHS), between 1980–2014, and from 37,716 men aged 40–75 years in the Health Professionals Follow-up Study (HPFS; 1986–2014). After controlling for other dietary and lifestyle factors, the researchers’ analyses pointed to a strong link between SSBs and increased risk of early death. Compared with drinking SSBs less than once per month, drinking one to four sugary drinks per month was linked with a 1% increased mortality risk. Two to six servings per week was associated with a 6% increase, one to two per day with a 14% increase, and two or more per day with a 21% increase. There was a notably strong association between SSB consumption and death from CVD. Compared with participants who only infrequently drank SSBs, those who consumed two or more SSB servings per day exhibited a 31% higher risk of premature death from CVD. And each additional SSB serving increased this risk by a further 10%.
The results also suggested a smaller link between SSB consumption and risk of early death from cancer. “Modest associations between SSB intake and cancer mortality were observed among both cohorts,” the researchers wrote. When comparing the most extreme categories, “among women, there was a positive association between intake of SSB and breast cancer mortality.” Also, “a borderline positive association was observed between SSB intake and colon cancer in both cohorts,” the team reported. ASB intake in the highest category was similarly positively associated with the risk of total and CVD mortality in the NHS.
“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, commented co-author Walter Willett, MD, professor of epidemiology and nutrition. ”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.”
Interestingly, while consuming ASBs instead of SSBs did reduce the risk of early death—“substituting one serving per day of SSB with ASB was associated with modest reductions in total and cause-specific mortality”—there was also a link between higher levels of ASB consumption (at least four servings per day) and a small increase in overall mortality and death due to early CVD among women.
“In these two large prospective cohorts of U.S. men and women, we found a positive graded association with dose between intake of SSBs and risk of mortality after adjusting for diet and lifestyle factors,” the researchers concluded. “Our results support recommendations and policies to limit intake of SSBs and to consume ASBs in moderation to improve overall health and longevity, the authors concluded. “ASBs could be used to replace SSBs among habitual SSB consumers but higher consumption of ASBs should be discouraged.”