A greater increase in coffee and tea consumption from before to after a diabetes diagnosis was also associated with lower death rates. These findings highlight the potential role of healthy beverage choices in managing risk for adults with type 2 diabetes, say the authors.
Type 2 diabetes
In 2021, over 500 million adults worldwide had type 2 diabetes, which carries an increased risk of CVD and premature death, and this number is set to rise to 783 million by 2045. Diet plays a key role in managing diabetes, but little is known about intake of specific types of beverages in relation to death and CVD among adults with type 2 diabetes.
Research
To fill this knowledge gap, researchers drew on data for 15,486 adults (74% women; average age 61 years) with a diagnosis of type 2 diabetes who were part of the Nurses’ Health Study (1980-2018) and Health Professionals Follow-Up Study (1986-2018) in the United States.
Beverage consumption was assessed using a validated food questionnaire and updated every two to four years. This included sugar sweetened beverages (SSBs), artificially sweetened (low-calorie) beverages (ASBs), fruit juice, coffee, tea, low fat and full fat milk, and plain water.
Results
During an average 18.5 years of follow-up, the researchers recorded 3,447 cases of CVD and 7,638 deaths.
After accounting for other lifestyle factors and medical history, they found that participants with the highest intake of SSBs (more than one serving a day) had a 20% increased risk of death from any cause compared with participants with the lowest intake (less than one serving a month).
In contrast, high intakes of certain beverages (up to six servings a day) were associated with lower mortality: 26% lower for coffee, 21% for tea, 23% for plain water, and 12% for low fat milk.
Similar associations were seen between the individual beverages and CVD rates and mortality. In particular, SSB intake was associated with a 25% higher risk of CVD and a 29% higher risk of CVD related mortality, whereas intake of coffee and low fat milk were associated with an 18% and 12% lower risk of CVD, respectively.
Compared with those who did not change their consumption of coffee in the period after a diabetes diagnosis, an 18% lower all-cause mortality was seen in those who increased their consumption of coffee. A similar pattern for all-cause mortality was also found for tea, and low fat milk.
Replacing SSBs with ASBs was also associated with lower all-cause mortality and CVD mortality, and replacing SSBs, ASBs, fruit juice, or full fat milk with coffee, tea, or plain water was consistently associated with lower all-cause mortality.
Observational study
This is an observational study, so can’t establish cause, and the researchers acknowledge that individual beverage consumption may be linked to other dietary and lifestyle risk factors for CVD and mortality among adults with diabetes, and they can’t rule out the possibility that measurement errors or misclassification may have influenced the results.
However, this was a large study with a long follow-up period, high response rates, and detailed and repeated assessments of dietary and lifestyle variables before and after a diabetes diagnosis.
Conclusions
The researchers concluded: “Overall, these results provide additional evidence that emphasises the importance of beverage choices in maintaining overall health among adults with diabetes.” Further studies are warranted to replicate and further explore these important associations, they add.
This new study extends the understanding of the health implications of different beverages to adults with type 2 diabetes, says Nita Forouhi at the MRC Epidemiology Unit, University of Cambridge, in a linked editorial.
Questions remain, however, such as the effect of adding sugar to coffee or tea, and the impact of other popular drinks, like milkshakes, smoothies, and hot chocolate, she writes. It is also unclear whether the findings apply to different population groups as the study focused on predominantly white US health professionals.
Nevertheless, choice of beverage clearly matters, she says. The case for avoiding sugar sweetened beverages is compelling in the general population, and it is reasonable to shift the focus to drinks that are most likely to have positive health effects: coffee, tea, plain water, and low fat milk, she concludes.