Increasing diet soda intake is directly linked to greater abdominal obesity in adults 65 years of age and older, according to a study published March 17 on the website of the Journal of the American Geriatrics Society. These findings raise concerns about the safety of chronic diet soda consumption, which might increase belly fat and contribute to greater risk of metabolic syndrome and cardiovascular diseases.
Metabolic syndrome — a combination of risk factors that may lead to high blood pressure, diabetes, heart disease and stroke — is one of the results of the obesity epidemic. The World Health Organization estimates 1.9 billion adults were overweight (body mass index of 25 or more) in 2014. Of this group, 600 million people fell into the obese range (BMI of 30 or more) — which has more than doubled since 1980.
To fight obesity, many adults try to reduce sugar intake by turning to nonnutritive or artificial sweeteners, such as aspartame, saccharin or sucralose.
In the past 30 years, artificial sweeteners and diet soda intake have increased, yet the prevalence of obesity also has seen a dramatic increase in the same time period, according to previous research. Many of the studies exploring diet soda consumption and cardiometabolic diseases have focused on middle-aged and younger adults.
“Our study seeks to fill the age gap by exploring the adverse health effects of diet soda intake in individuals 65 years of age and older,” lead author Sharon Fowler, MPH, from the University of Texas Health Science Center at San Antonio, said in a news release.
“The burden of metabolic syndrome and cardiovascular disease, along with healthcare costs, is great in the ever-increasing senior population.”
The San Antonio Longitudinal Study of Aging enrolled 749 Mexican- and European-Americans who were 65 and older at the start of the study, from 1992-96. Researchers measured diet soda intake, waist circumference, height and weight at study onset, and at three follow-ups in 2000-01, 2001-03, and 2003-04, for a total of 9.4 follow-up years. At the first follow-up there were 474 (79.1%) surviving participants; there were 413 (73.4%) at the second follow-up and 375 (71.0%) at the third follow-up.
The findings show the increase in waist circumference among diet soda drinkers, per follow-up interval, was almost triple the increase among nonusers: 2.11 cm versus 0.77 cm, respectively. After the researchers adjusted for multiple potential confounders, interval waist circumference increases were 0.77 cm for nonusers, 1.76 cm for occasional users and 3.04 cm for daily users. This translates to waist circumference increases of 0.80 inches for nonusers, 1.83 inches for occasional users and 3.16 inches for daily users during the total 9.4-year SALSA follow-up period.
“The SALSA study shows that increasing diet soda intake was associated with escalating abdominal obesity, which may increase cardiometabolic risk in older adults,” Fowler said in the release. Study authors wrote that older individuals who drink diet soda daily, particularly those at high cardiometabolic risk, should try to curb their consumption of artificially sweetened drinks.
“For this reason, dietary counseling for older individuals would ideally include the promotion of unsweetened coffee and tea, mineral water — unsweetened or lightly sweetened with 100% fruit juice — or simply water as alternatives to highly sweetened beverages,” the authors wrote in the study’s conclusion. “Such alternatives would provide hydration and intake of natural antioxidants while decreasing intake of diet beverages, which are intensely sweet and — like their sugar-sweetened counterparts – have been associated with significantly greater incidence of cardiometabolic disease and other health problems.”