Diet Soda and Cardiometabolic Risk: Study Does Not Prove Link

ATLANTA (March 30, 2012) — The findings presented in the “Dietary patterns matter: diet beverages and cardiometabolic risks in the longitudinal Coronary Artery Risk Development in Young Adults (CARDIA) Study” confirm what previous studies have shown about the importance of total diet, but fail to show that beverages sweetened with low-calorie sweeteners have an effect on cardiometabolic outcomes.

The Calorie Control Council* cites the following as serious limitations of the study:

• This study was observational, so it was designed to evaluate potential associations, not prove cause and effect.
• Although this study followed people over 20 years, the analyses were done based on the diet at the beginning of the study.  Dietary patterns could have changed over that time period, especially if given a cardiometabolic related diagnosis and/or told by a healthcare professional to modify diet.
• While the authors stated that “consumption of diet beverages in the context of a Western dietary pattern was generally associated with a higher risk of metabolic outcomes,” the results were not statistically significant.  This means that the findings were just as likely to have occurred by chance.
• Researchers noted the lack of consistency between the use of low-calorie beverages and cardiometabolic outcomes.  Although researchers tried to control for many variables, it is entirely possible that other factors besides diet beverage consumption that were not controlled for may have influenced results.
• This study examined the use of “diet beverages” but did not account for other sources of low-calorie sweeteners in the diet.  Additionally, diet beverages are made with a variety of low-calorie sweeteners; however, this study did not control for variations in types of sweeteners and amounts.
• This study relied on self-reported dietary data over a month.  Previous studies have shown that people tend to under-report their calorie intake and overreport their physical activity levels.  Thus, the diet data may not be accurate, which may introduce some error into the study.

This study confirmed what other scientific research has shown:

• People who consumed diet beverages were also more likely to be consuming a healthier diet.
• People who did not consume diet beverages were more likely to consume more calories.
• Total dietary pattern has an impact on health.  A diet high in fruit, fish, and whole grains such as the “Prudent” diet cluster in this study can lower the risk of cardiometabolic outcomes.