Regular soft drink consumption may raise mortality risk

A new study from Europe suggests that daily consumption of soft drinks, be it sugar- or artificially-sweetened, could be linked to an elevated mortality risk.

“[G]reater consumption of total, sugar-sweetened, and artificially sweetened soft drinks was associated with a higher risk of all-cause mortality,” said the researchers. “The results of this study are supportive of ongoing public health campaigns aimed at reducing the consumption of soft drinks.”

Study participants comprised 451,743 individuals (mean age 50.8 years, 71.1 percent female) from the EPIC* cohort, an ongoing study with participants from 10 European countries**. Individuals with cancer, heart disease, stroke, or diabetes at baseline were excluded, as were those with “implausible dietary intake data”. Information on dietary intake was acquired through interviews, questionnaires, or diet diaries. There were 41,693 deaths over the mean 16.4-year follow-up period, 43.2, 21.8, and 2.9 percent due to cancer, circulatory disease, and digestive diseases, respectively.

Compared with individuals who consumed <1 glass (250 mL) of total soft drink*** per month, those who consumed ≥2 glasses of soft drink per day were at a higher risk of all-cause mortality (hazard ratio [HR], 1.17, 95 percent confidence interval [CI], 1.11–1.22; p<0.001). [JAMA Intern Med 2019;doi:10.1001/jamainternmed.2019.2478]

This elevated risk applied to individuals who consumed ≥2 glasses/day of sugar-sweetened soft drinks (HR, 1.08, 95 percent CI, 1.01–1.16; p=0.004) or artificially-sweetened soft drinks (HR, 1.26, 95 percent CI, 1.16–1.35; p<0.001) compared with those who consumed <1 glass of these respective drinks per month.

Subgroup analysis showed that the all-cause mortality risk was elevated even in individuals with a healthy weight (BMI <25; HR, 1.18, 1.11, and 1.27 for ≥1 glass/day vs <1 glass/month of total, sugar-sweetened, and artificially-sweetened soft drinks, respectively).

“These results may suggest that soft drinks alter mortality risk independently of adiposity,” said the researchers.

All-cause mortality risk was also elevated with regular consumption of sugar-sweetened soft drinks among obese (BMI ≥30) but not overweight (BMI 25–30) individuals (HR, 1.23 vs 0.98; p=0.002), though the reasons for this were less clear, they said.

Compared with <1 glass/month, consumption of ≥2 glasses/day of total soft drinks or artificially-sweetened soft drinks was associated with a higher risk of circulatory disease-related mortality (HR, 1.27 and 1.52; p<0.001 for both), while ≥1 glass/day of total (HR, 1.50) or sugar-sweetened soft drinks (HR, 1.59; p<0.001 for both) was linked to a higher risk of digestive disease-related mortality.

Consuming ≥1 glass/day of total soft drink, vs <1 glass/month, was also associated with elevated risks of death due to cerebrovascular disease (HR, 1.30; p<0.001), ischaemic heart disease (HR, 1.19; p=0.001), and Parkinson disease (HR, 1.59; p=0.02), while ≥1 glass/day of artificially-sweetened soft drink was associated with an elevated risk for ischaemic heart disease-related death (HR, 1.41; p=0.003).

Overall, soft drink consumption appeared unrelated to cancer deaths, though ≥1 glass/day of soft drink was linked to a higher risk of colorectal cancer death than <1 glass/month (HR, 1.25; p=0.004).

“[This study] confirms the adverse effects of sugar-sweetened beverages and continues to put the question forward about the detrimental effects of artificially-sweetened beverages,” said Professor Mitch Elkind, 2019-20 President-elect of the American Heart Association, who was unaffiliated with the study.

While the reasons for these effects may be undetermined, “there may be direct adverse effects of the artificial sweeteners on the physiologic system, on the metabolism,” said Elkind. People who consume artificially-sweetened drinks may also “think they can get away with” other unhealthy habits as a result, he said. 

Further studies should investigate the effects of long-term consumption of artificial sweeteners, said the researchers, as well as the potential connection between soft drink consumption and cancer and Parkinson disease.