A new study, published in the Journal of the American Geriatric Society, indicates a direct link between the consumption of diet soda and an increase in abdominal obesity in people 65 years of age and older. Weight gain leads to a greater risk of metabolic syndrome and cardiovascular disease.
Metabolic Syndrome is the prevalence of a certain set of biomarkers that indicate a disorder of energy utilisation and storage in the body. It is a precursor of ill health such as diabetes and heart disease. The biomarkers are: abdominal obesity, high blood pressure, high cholesterol and unhealthy levels of glucose.
Concerned about the great health and economic impact of this on the aging population, the University of Texas Health Science Center at San Antonio investigated further:
The San Antonio Longitudinal Study of Aging (SALSA) analysed the effects of diet soda consumption on 749 subjects over a period of 9.4 years. The subjects were over the age of 65 and were comprised of mixed ethnicity (Mexican and European-American). Previous studies 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,” explains lead author Sharon Fowler, MPH, and faculty associate in the division of clinical epidemiology at 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.”
In South Africa, our senior population consists of 4.1 million people. As such, 8% of our population is affected by the findings of this study.
Obesity in South Africa has lead to a 34% increase in health care costs. Earlier this year CNBC Africa reported that the healthcare costs associated with obesity could cost the South African economy 13.5 trillion rand a year.
In an effort to dispel obesity, many adults substitute sugar with non-nutritive or artificial sweeteners, such as aspartame, saccharin, or sucralose. In the past 30 years, studies have shown that artificial sweetener and diet soda intake has increased, yet obesity prevalence has increased within the same period.
The SALSA study measured diet soda intake, waist circumference, height and weight from the outset. It then had check points with three follow-ups throughout the period. Findings indicated that the waist circumference of diet soda drinkers increased by triple the amount of that of non users.
After allowance for multiple potential confounders, interval waist circumference increases were 0.77 cm for non-users, 1.76 cm for occasional users, and 3.04 cm for daily users.
“The SALSA study shows that increasing diet soda intake was associated with escalating abdominal obesity, which may increase cardio-metabolic risk in older adults,” says Sharon Fowler.
However, what the multiple potential confounders are has not been released.
Obesity researcher Barry Popkin, PhD, head of the division of nutrition epidemiology at the University of North Carolina, Chapel Hill, disputes the claim that the consumption of diet soda increases weight gain by pointing out that the science in this area is inconclusive.
Impact of Artificial Sweeteners on Weight
In a 2009 analysis, Popkin and co-author Richard D. Mattes, PhD, MPH, RD, and a nutrition professor at Purdue University, reviewed the research examining the impact of artificial sweeteners on weight.
They found little to support the idea that no-calorie sweeteners stimulate appetite or contribute to obesity in some other way, however, further research is required before final conclusions can be drawn.
A previous study done in San Antonio Texas, called the San Antonio Heart Study followed more than 5 000 adults for between seven and eight years and found that people who drank more diet soda gained more weight over time. However, because this study, as with the one newly released and mentioned above, was observational, it is difficult to say whether or not the consumption of diet soda played a direct role in the weight gain that took place.
What could be happening is what Popkins refers to as “The Big Mac and Diet Coke” mentality. This mentality describes the process whereby people who realise they are gaining weight, switch to drinking diet soda without addressing the other aspects of their diet that may be causing weight gain.
Sharon Fowler, head of the San Antonio Study, acknowledges this, but remains concerned.
“I am not convinced these sweeteners are as safe as they should be, given their widespread use,” says Fowler, “I am concerned that we are in the middle of a giant experiment and we don’t know the outcome.”