Diet sodas have received a lot of attention from various Internet sources claiming they cause insulin spikes in the body. These reports may be exaggerated as insulin primarily responds to blood glucose levels. To understand how diet sodas may affect insulin, you need to understand how insulin works and what artificial sweeteners are. The most reliable scientific reports are delivered by experts in the field and are often available for view in peer-reviewed journals and government websites.
How Insulin Works
Insulin is a hormone secreted by the pancreas when blood sugar or glucose levels rise. Insulin maintains glucose levels in the blood and is chiefly responsive to its fluctuations only in the bloodstream. When insulin is released, cells receive a signal that causes the uptake of glucose into the cells and out of the bloodstream. Glucose is then stored for energy use when needed. The entire process is a "building" phase, which also promotes fat storage.
To make an informed decision about how artificial sweeteners may affect the body, it is important to understand what they are. The most common artificial sweeteners present in diet soda are aspartame, sucralose and acesulfame-K. Aspartame is made of two amino acids, phenylalanine and aspartic acid. Sucralose is a complex molecule made of sucrose, galactose and chlorine molecules. Acesulfame-K is made up of carbon, nitrogen, oxygen, hydrogen, sulfur and potassium. All components are present in foods and the body.
There is minimal evidence to suggest that insulin rises after drinking diet sodas. In a study published in the journal “Food and Nutrition Research” in 2011, researchers report higher amounts of insulin in the blood of 12 healthy overweight subjects randomized to consume sucrose-sweetened foods/drinks compared to 11 subjects consuming artificially sweetened foods/drinks. In a brief report published in “Diabetes Care” in 2009, 22 normal/overweight subjects were given oral glucose and drank diet soda or carbonated water. Insulin was higher in those given diet soda, but results were not statistically significant.
Possible Gut Action
Researchers are attempting to pinpoint the exact effect of artificial sweeteners in the body. In the “Diabetes Care” report, researchers found that subjects consuming diet soda did have significant increases in glucagon-like peptide 1, a gut hormone responsible for promoting energy storage and insulin action and decreasing appetite. Results suggest that diet soda does increase insulin via gut action, but only when glucose is also present. Therefore, diet soda may increase the efficiency of blood glucose control and promote earlier satiety.
Sweet Taste Does Not Increase Insulin
A reseacher from the Monell Chemical Senses Center has demonstrated in several human studies that the cephalic phase insulin response, or insulin released due to a sweet taste, is not stimulated by sugar or artificially sweetened beverages. Diet soda may influence glucose metabolism at the gut level. However, it may not necessarily be a bad thing. It is important to remember that there are various artifical sweeteners found in different products and they may not similarly influence nutrient absorption.