Contributing researchers to this cross-country paper came from Singapore, China and the United States, and the analysis was conducted using data from close to 17,000 Singaporean Chinese subjects between the ages of 45 and 74.
The subjects were assessed via surveys and face-to-face interviews, and cognitive impairment was determined using the Singapore-Modified Mini-Mental State Examination (SM-MMSE).
All subjects were also participants of the Singapore Chinese Health Study (SCHS) starting in the 1990s, with three follow-ups in the subsequent years between 1999 and 2016, from which data was used to determine their SSB consumption in younger years.
The main types of SSBs included in this study were carbonated soft drinks, orange juice and other fruit and vegetable juices. Participants were classified based on whether they ‘hardly drink’ these, ‘drink one to three times per month’, ‘once per week’ and ‘two times or more per week’.
“The average age of the subjects we followed up specifically regarding dementia was 73.2 years old,” said the researchers.
“Based on SM-MMSE criteria 2,443 (14.4%) of them were found to have cognitive impairment, but we did not observe any statistically significant difference between the group that rarely drank carbonated soft drinks or fruit/vegetable juices and the groups that had consumed these at least twice a week, once a week or one to three times a month.”
Interestingly, based on data from the study it would also seem that the group that rarely drank carbonated soft drinks showed somewhat higher rates of dementia (15.3%) as compared to the ones that drank these one to three times a month (12.7%), once a week (12.9%) and more than twice a week (11.0%).
Ethnic-specific studies needed for better understanding
The researchers offered several potential explanations for their findings, and the failure to detect any sort of significant correlation between SSB consumption and dementia as has been seen in other ethnicities.
“More than 73% of the subjects (more than 12,000) in this study did not drink sugary beverages as opposed to other studies conducted so far where this consumption was much more common,” they said.
“It is also notable that we were trying to make a correlation between their SSB consumption in the 1990s versus their cognitive function some 20-odd years later, [where their dietary habits may have changed.
They also pointed out that some ethnicity-based studies such as the United States’ Boston Puerto Rican Health Study had found statistically significant correlations between SSB consumption and cognitive decline, calling for further research to be conducted for the Chinese population as well.
“This study was the first ever conducted in an ethnic Chinese population to determine the correlation between their SSB consumption rate and risk of dementia,” said the researchers.
“Today, the consumption of SSBs has become more widespread and common, especially amongst the middle-aged population in China, leading to higher rates of obesity, [another significant health issue].
“Although we do not expect this to directly represent all of the Chinese population e.g. in China, but it can serve as a reference for future research [and] it also has a large sample size with detailed data and variables observed over a long follow-up period of time.”
Study: Sugar-sweetened beverages consumption in midlife and risk of late-life cognitive impairment in Chinese adults
Source: Chinese Journal of Epidemiology
Authors: Zhang, Y. et. al.