PhotoPeople drink diet soda because -- well, it's diet so they think it will help them lose weight. But a new study finds that in adults 65 and older, increasing diet soda intake is directly linked to obesity, specifically abdominal obesity. Belly fat, in other words.

The findings, published in the Journal of the American Geriatrics Society, raise concerns about the safety of chronic diet soda consumption, which could contribute to increased risk of metabolic syndrome and cardiovascular diseases.

Metabolic syndrome, which can lead to high blood pressure, diabetes, heart disease, and stroke, is one of the results of the obesity epidemic.

An industry group took issue with the study.

“Previous research, including human clinical trials, supports that diet beverages are an effective tool as part of an overall weight management plan. Numerous studies have repeatedly demonstrated the benefits of diet beverages – as well as low-calorie sweeteners, which are in thousands of foods and beverages – in helping to reduce calorie intake," the American Beverage Association said in a prepared statement. "It’s important to recognize that this observational study looked at an aging population – those over 65 at the beginning of the study, who are already at risk of weight gain and cardiovascular disease – and then made conclusions based on associations."

Rates have risen

Interestingly, obesity rates have risen at the same time as diet soda's popularity has taken off. While previous studies have looked at the effects of diet soda on the young and middle-aged, this one looked at older Americans.

"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," explained lead author Sharon Fowler, MPH, from the University of Texas Health Science Center at San Antonio. "The burden of metabolic syndrome and cardiovascular disease, along with healthcare costs, is great in the ever-increasing senior population."

The study -- dubbed the San Antonio Longitudinal Study of Aging (SALSA) -- enrolled 749 Mexican- and European-Americans who were aged 65 and older at the start of the study (1992-96). Diet soda intake, waist circumference, height, and weight were measured at study onset, and at three follow-ups. 

"The SALSA study shows that increasing diet soda intake was associated with escalating abdominal obesity, which may increase cardiometabolic risk in older adults," Fowler concluded.

The researchers recommend that older individuals who drink diet soda daily, particularly those at high cardiometabolic risk, should try to cut back.


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