Reference
Malik VS, Li Y, Pan A, et al. Long-term consumption of sugar-sweetened and artificially sweetened beverages and risk of mortality in US adults. Circulation. 2139(18):2113-2125.
Objective
To determine whether sugar-sweetened beverage consumption is associated with risk of mortality.
Design
The relationship between consumption of sugar-sweetened beverages (SSBs) or artificially sweetened beverages (ASBs) was examined to determine association with risk of total and cause-specific mortality among 2 large cohorts. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).
Participants
Data from 37,716 men in the Health Professional’s Follow-up study (HPFS; 1986 to 2014) and 80,647 women from the Nurses’ Health study (NHS; 1980 to 2014) were analyzed to determine any association.
Study Parameters Assessed
Beverage consumption data was derived from questionnaires completed by NHS and HPFS participants. Total SSBs were defined as caffeinated colas, caffeine-free colas, other (noncola) carbonated sugar-sweetened beverages, and noncarbonated sugar-sweetened beverages (fruit punches, lemonades, or other fruit drinks). Fruit juice was not considered an SSB. Artificially sweetened beverages were defined as caffeinated, caffeine-free, and noncarbonated low-calorie or diet beverages.
Causes of death were tracked to distinguish between death from cardiovascular disease (CVD), cancer, breast cancer, lung cancer, and colon cancer mortality. Possible covariates were tracked to establish possible confounders related to lifestyle factors and medical history, including age, body weight, smoking status, physical activity, medication and supplement use, disease diagnoses, and family history of chronic diseases.
Outcome Measures
Death due to any cause during the follow-up period (28 years for HPFS and 34 years for NHS).
Key Findings
During 34 years of follow-up in the NHS, 23,432 deaths (4,139 CVD and 8,318 cancer) occurred, and during 28 years of follow-up in the HPFS, there were 13,004 deaths (3757 CVD and 4062 cancer). During these periods of time, mean consumption of SSBs decreased in both cohorts. Intake of ASBs increased initially and then decreased.
Men and women with higher intakes of SSBs tended to be younger, less physically active, less likely to take a multivitamin, and more likely to smoke compared to those with lower intakes. Sugar-sweetened beverage consumption was also associated with a higher intake of total energy, red and processed meat, and glycemic load. At the same time, SSB consumption was associated with lower intake of whole grains and vegetables. Individuals who drank more ASBs were also younger, more likely to have hypertension, and more likely to be overweight. Artificially sweetened beverage intake was associated with a lower glycemic load.
After adjusting for age and ASB consumption, intake of SSBs was associated with an increased risk for total mortality in both cohorts. Compared with those who consumed SSBs less than once a month, women who consumed ≥2 servings of SSBs per day had a 63% higher risk of death (HR: 1.63; 95% CI: 1.52-1.75). For men there was a 29% increased risk (HR: 1.29; 95% CI: 1.15-1.44). For men and women combined, HR was 52% higher (HR: 1.52; 95% CI: 1.43-1.61).
After adjusting for demographic and lifestyle factors (smoking, alcohol intake, postmenopausal hormone use [NHS], physical activity, family history of diabetes mellitus, family history of myocardial infarction, family history of cancer, multivitamin use, ethnicity, and aspirin use), the association was only slightly weakened (HR: 1.30; 95% CI: 1.22-1.38). Additional adjustment for baseline hypertension and hypercholesterolemia, intake of whole grains, fruit, vegetables, red and processed meat, total energy, and BMI further weakened the association, dropping it to a 21% increase in risk (HR: 1.21; 95% CI: 1.13-1.28; P trend<0.001).
Compared with those who consumed SSBs less than once a month, women who consumed ≥2 servings of SSBs per day had a 63% higher risk of death.
Each serving per day–increment in SSB was associated with a 7% higher risk of death (HR: 1.07; 95% CI: 1.05-1.09). The association was stronger among those in the NHS than HPFS (P interaction=0.02). It didn’t seem to matter what type of SSB a person drank; the same 7% higher risk of death per daily serving held.
The risk for CVD mortality was more pronounced than for cancer mortality.
In the pooled, fully adjusted analysis, compared to infrequent consumers, those who consumed ≥2 servings of SSBs per day had a 31% (HR: 1.31; 95% CI: 1.15-1.50; P trend<0.0001) higher risk of death from CVD. Estimates were greater in the NHS compared to HPFS but no interaction with sex was observed (P interaction=0.70). Each serving per day increment of SSBs was associated with a 10% higher risk of CVD death (HR: 1.10; 95% CI: 1.06-1.14).
Among women, there was a positive association between intake of SSB and a 34% increased risk of breast cancer mortality (HR: 1.34; 95% CI: 1.00-1.80; P trend=0.02), comparing highest to lowest consumers.
The ASBs appear to have a much smaller impact. Intake of ASBs was positively associated with risk of total and CVD mortality in the highest intake category in the NHS: 2 or more servings per day was associated with a 10% increase in risk for total mortality and 15% for CVD mortality. Although risk trended steadily higher at lower consumption, the data did not reach statistical significance.
After adjusting for incidence of intermediate conditions (hypertension, hypercholesterolemia, type 2 diabetes mellitus, CHD, and stroke) during follow-up, the association between ASBs and total mortality in NHS was no longer significant (HR comparing extreme categories: 1.00; 95% CI: 0.94-1.06).
Intake of ASBs was not associated with cancer mortality in either cohort. In the NHS there was a positive association between ASB and total and CVD mortality at high intake levels (≥4 servings per day), with a 30% increase in risk for total mortality and a 43% increase for CVD mortality. Again, this was only seen in the NHS data; no associations were observed in HPFS.
Practice Implications
We should begin by pointing out that some of the biggest names at Harvard’s Channing School of Public Health are among this paper’s authors. While association does not prove causation, the associations found between SSBs and mortality in this study are likely real; therefore, these results deserve some attention. According to this study, consuming moderate levels of sugar-sweetened beverages (at 2 per day) and higher levels of artificially sweetened beverages (4 per day) was associated with poor outcomes.
Current government dietary recommendations suggest added sugars should make up no more than 10% of total energy in the diet.1 Among young adults, SSBs contribute 9.3% of daily calories in men and 8.2% in women.2 Sweetened beverages on their own nearly exceed the total suggested sugar intakes. Globally the situation may be worse than in the United States.3
The findings of this study are of particular relevance and timely. In April 2019, the American Academy of Pediatrics endorsed a number of policies to curb sugar consumption in children, including the controversial policy of taxing SSBs.4 Children and teens in the United States consume about 150 calories a day, on average, from SSBs, which is about 12 ounces per day.5
In November 2014, Berkeley, California became the first locality in the United States to approve a tax on SSBs. The tax went into effect January 1, 2015.6 Other cities have copied Berkeley’s example. It appears that imposing these taxes does reduce consumption. A paper published in the April 2019 issue of the American Journal of Public Health reports a significant 52% reduction in consumption of sugar-sweetened soda in Berkeley following enactment of the law.7
The National Bureau of Economic Research reports that Philadelphia’s soda tax was associated with a reduction in adults’ frequency of regular soda consumption by 10.4 times per month.8 On the other hand, a close examination of sales records suggests the response has been more complicated. Unpublished research suggests that although soda sales dropped within the city limits, they increased outside the tax area—people just shopped for soda in the suburbs. After the math was done consumption may have only dropped by 20%.9
The soda industry is unhappy with the moves to limit consumption of their products and are funding lobbying efforts to prevent enactment of these soda tax laws.10
Four cities in California now have soda taxes. The beverage industry in California has successfully halted any new laws that may limit their sales, influencing the legislature to pass a 12-year moratorium on further soda taxes.11
Boulder, CO, passed a soda tax of 2 cents per ounce in 2016. By August 2018, the city was on its way to taking in 5.8 million dollars. Boulder’s challenge has been what to do with the millions of dollars of income. Colorado’s Taxpayers’ Bill of Rights (TABOR amendment to the State Constitution) requires the city to ask voters whether it can keep the extra money.12
This study provides the most comprehensive data to date to quantify the risks of sugar-sweetened beverages to public health. Its results suggest that reducing consumption of sugary beverages could literally be a matter of life and death.
