Coffee sweetened with sugar has similar mortality benefits to unsweetened coffee, although artificial agents provide a less consistent benefit
Drinking coffee sweetened with sugar provides broadly similar mortality benefits to consumption of unsweetened coffee although benefits from drinking coffee sweetened with artificial agents are much less consistent.
This was the finding of a prospective cohort study by a team of researchers based at the Department of Epidemiology, School of Public Health, Southern Medical University, Guangdong, China.
A 2019 meta-analysis concluded that moderate coffee consumption, for example, 2 to 4 cups every day, was associated with reduced all-cause and cause-specific mortality in comparison to those who did not consume the beverage. In fact, consumption of 8 or more cups of coffee per day, even among those with slower or faster caffeine metabolism, has been shown to be inversely associated with mortality.
Nevertheless, what has not been explored in the literature is the extent to which sweetened coffee retains these health benefits, given the potential adverse health effects of sweetened beverages.
For the present study, the researchers turned to data held in the UK Biobank to determine the association between consumption of coffee sweetened with either sugar or artificial agents and overall and specific cause mortality. A further objective was to explore whether sweetening affected any mortality benefits depending on how the coffee was prepared, e.g., instant, ground, or decaffeinated.
Participants in the UK Biobank completed dietary recall data using a web-based questionnaire from which the researchers collected information on whether sugar or artificial sweeteners were used in coffee. The level of coffee consumption was categorised as 0 – 1.5 cups/day, > 1.5 – 2.5 cups/day, > 2.5 – 3.5 cups/day and > 4.5 cups/day and the type of coffee drank was classed as instant, ground or decaffeinated.
Regression analysis was used to estimate the hazard ratios for coffee consumption and mortality, adjusted for several factors such as age, gender, co-morbidities etc.
Coffee sweetened with sugar/artificial agents and mortality outcomes
A total of 171,616 individuals with a mean age of 55.6 years (44.6% male) were included in the final analysis and followed for a median of 7 years. Among this cohort, 24.2% were non-coffee drinkers, 55.4% drank unsweetened coffee with the remainder adding either sugar (14.3%) or artificial sweeteners (6.1%). Those who sweetened their coffee added an average of 1.1 teaspoons of sugar and 1.4 teaspoons of a sweetener.
During the follow-up period there were 3177 deaths, 1725 from cancer and 628 from CVD. Compared with those who did not drink coffee, after adjustment, the risk of death associated with drinking > 3.5 to 4.5 cups of unsweetened coffee/day was 29% lower (hazard ratio, HR = 0.71, 95% CI 0.60 – 0.84).
For those drinking a similar amount of coffee sweetened with sugar, there was a similar reduced risk of death (HR = 0.79, 95% CI 0.60 – 1.06). For the same level of consumption, drinking coffee sweetened with an artificial agent had a significant all-cause mortality benefit (HR = 0.65, 95% CI 0.45 – 0.92).
When considering how the coffee was prepared, there were significant mortality benefits associated with drinking > 3.5 to 4.5 cups/day of unsweetened coffee. In contrast, the mortality benefits for a similar level of consumption of sugar-sweetened coffee were slightly less and non-significant for all three methods of preparation.
Among those using artificial sweeteners, benefits were derived from instant (HR = 0.66, 95% CI 0.46 – 0.96) and ground coffee (HR = 0.51, 95% CI 0.27 – 0.95) but not decaffeinated (HR = 0.52, 95% CI 0.23 – 1.17).
The authors concluded that taking the data as a whole, it seemed that consumption of either unsweetened or sugar-sweetened coffee provided broadly similar mortality benefits. In contrast, the effect of sweetening coffee with artificial agents was less consistent, possibly due to the smaller number of people in this group.
Liu D et al. Association of Sugar-Sweetened, Artificially Sweetened, and Unsweetened Coffee Consumption With All-Cause and Cause-Specific Mortality. A Large Prospective Cohort Study Ann Intern Med 2022