Type 2 diabetes is the development of insulin resistance in the body. This causes high levels of glucose in the blood. Over time, high levels of glucose can lead to serious complications such as heart and blood vessel disease, blindness, and kidney disease. The development of type 2 diabetes is strongly influenced by being overweight and by dietary choices. Diet sodas are a common option for people who are trying to cut down on sugar and calories in their diet. However, some studies have suggested that diet sodas may not be completely harmless.
Researchers from the University of Texas Health Sciences Center wanted to determine if there was an association between diet soda and the development of type 2 diabetes. The study, published in the journal Diabetes Care, suggested that heavy diet soda drinkers may actually increase their risk of type 2 diabetes.
This study collected information from a larger study called the Multi-ethnic Study of Atherosclerosis (MESA). The MESA study followed 6,814 individuals. A food frequency questionnaire and a fasting blood glucose test were collected at the start of the study and during three follow-up appointments scheduled at two-year intervals. The results showed that the risk of type 2 diabetes increased as the intake of diet soda increased.
Researchers also considered other factors that are known to influence the development of diabetes, such as age, physical activity, and waist circumference. Even after accounting for these factors, when compared to those who never drink diet sodas, the risk of type 2 diabetes increased by:
This study was based on an observational study that simply observes participants as they live and makes no attempt to influence their dietary choices or other factors that may contribute to their risk of type 2 diabetes. Despite efforts to take these factors into account, results from this type of study are always in danger of being skewed by factors that are not accounted for. Therefore, this study cannot prove that diet soda causes type 2 diabetes. This study can only suggest that there may be a link. Further research with stricter study designs will help determine if diet sodas contribute directly to the development of type 2 diabetes. At this point, it is difficult to explain such a connection.
In the meantime, research has already shown that regular physical activity, weight control, and diets high in fiber and low in simple sugars do reduce the risk of type 2 diabetes. Until the question of diet soda’s contribution has been sorted out, water is always a good option when you are thirsty.
American Diabetes Association
American Dietetic Association
Nettleton JA, Lutsey PL, Wang Y, Lima JA, Michos ED, Jacobs DR. Diet soda intake and risk of incident metabolic syndrome and type 2 diabetes in the Multi-Ethnic Study of Atherosclerosis (MESA).Diabetes Care. 2009 Apr;32(4):688-94. Epub 2009 Jan 16.
Last reviewed May 2009 by Richard Glickman-Simon, MD