The Effect of Sucralose (Splenda®) on Blood Sugar Levels
Brian Kazempoor, Sarah Kantari, and Manuel Quinones
Department of Biological Sciences
Saddleback College
Mission Viejo, CA 92692
[Abstract here]
Introduction
Artificial sweeteners have been consumed since the accidental discovery of the first synthetic sweetener, saccharin (Sweet’N Low®), by Ira Remsen in 1879 (Bruice, 2013). Remsen found that the chemicals he was working with in his lab had an extremely sweet taste, and he subsequently ignited the revolution of artificial sweeteners. Remsen’s compound, which he would name saccharin, was 300 times sweeter than glucose. Since the discovery of saccharin, artificial sweeteners have been used in diets as substitutes for pure sugar in beverages and foods. Today, many people choose to use artificial sweeteners in tea, coffee, and baked goods. With careful testing, the Food and Drug Administration has approved five artificial sweeteners in the United States, all of which have no caloric value, nor do they substantially raise blood glucose levels: acesulfame potassium, aspartame, neotame, saccharin, and sucralose (American Diabetes Association, 2006).
Sucralose (Splenda®) is the newest synthetic sweetener that can be found in most coffee shops and teashops, and is widely preferred over sugar by many people, regardless of their diet. The benefits of sucralose include being 600 times sweeter than glucose, maintaining its sweetness in foods stored for long periods of time, and being able to withstand extreme baking temperatures (Binns, 2003). Sucralose is the only synthetic sweetener that has a carbohydrate-like structure, giving it the potential to be metabolized by the body. However, when digestion occurs, the human body does not recognize sucralose as a carbohydrate because of the three chlorine atoms that replace the hydroxyl groups of sucrose. This allows for sucralose to easily be eliminated from the body, rather than being metabolized (Kroger et al., 2006). Sucralose in theory should not raise blood sugar levels if the body does not metabolize it. In contrast to sucralose, glucose monomers of the polymer sucrose (table sugar) are absorbed into the bloodstream during digestion. Glucose plays an important role in cellular respiration for living organisms. Glucose is processed through a series of chemical pathways that allow for the production of mass quantities of ATP in the mitochondria of cells. Because it is metabolized, glucose should raise blood sugar levels. Based on such information, the investigators anticipated a significant difference in the blood sugar levels of people who consume table sugar and people who consume the artificial sweetener sucralose (Splenda®).
Materials and Methods
A TRUETrack® Blood Glucose Monitoring System was purchased from Walgreens (Mission Viejo, CA). Sterilization supplies, which include alcohol and cotton balls, and additional glucose strips were also purchased at Walgreens (Mission Viejo, CA). Arrowhead® distilled water, table sugar (C&H® pure sugar), and sucralose sweetener (Splenda®) were purchased from Albertsons (Mission Viejo, CA). The sharp box used to dispose of needles was obtained from one of the investigators’s employer, Ross Medical Associates (San Juan Capistrano, CA).
Data collection took place in April 2014 on the Saddleback College campus. The experimenters requested ten healthy (no prior history of blood sugar related health problems) Saddleback College students to volunteer in the experiment. After written consent from each volunteer was obtained, the subjects were asked to fast for 8 hours prior to each testing and data collection day. On the first day, the subjects’ blood glucose levels were tested before the consumption of unsweetened water. The subjects were then asked to drink distilled water with no sweetener. After 45 minutes, blood glucose levels were tested again. On the second day, the subjects’ blood glucose levels were tested before the consumption of table sugar-sweetened water. The subjects were then asked to drink the water with table sugar. After 45 minutes, blood glucose levels were tested again. On the third and final day, the subjects’ blood glucose levels were tested before the consumption of sucralose-sweetened water. The subjects were then asked to drink the water with sucralose sweetener. After 45 minutes, blood glucose levels were tested again. The sweetened waters contained 1 packet of sucralose or table sugar per 237 mL (1 cup), with the exact concentration being 4.219 grams of sweetener per liter. The 45-minute gap between consumption of the water and blood sugar testing allowed for the water to be digested. Blood glucose levels were tested using the TRUETrack® Blood Glucose Monitoring System. To analyze data, the experimenters conducted an Analysis of Variance (ANOVA) using Microsoft Excel. An analysis of variance was used to test for a significant difference in blood glucose levels with the unsweetened, sucralose sweetened, and table sugar sweetened waters. Using QuickCalcs on GraphPad Software, a Bonferroni post-hoc test was run to test for a significant difference in the data between two specific groups.
Results
Investigators tested the difference in blood glucose levels from fasting prior to consuming the water, and 45 minutes after consuming the water. Preliminary testing showed that the 45-minute mark after consumption was the average peak time in blood glucose levels. The mean difference in blood glucose levels with unsweetened water was 4.10 mg/dL (milligrams per deciliter) ± 0.66 mg/dL (±SE), N=10. The mean difference in blood glucose levels with table sugar-sweetened water was 14.10 mg/dL ± 1.37 mg/dL (±SE), N=10. The mean difference in blood glucose levels with sucralose-sweetened water was 4.40 mg/dL ± 0.58 mg/dL (±SE), N=10. Figure 1 represents the mean difference in blood glucose levels with the consumption of the three types of waters. After conducting a single factor ANOVA, a p-value of 2.0*10-8 was obtained. Because p<0.05 (95% confidence interval), a Bonferroni post-hoc test was run to test for a significant difference in the average difference in blood glucose levels when consuming table sugar and when consuming sucralose. The multiple comparison adjustment showed a statistical difference in blood glucose levels with table sugar-sweetened water and sucralose-sweetened water (Difference in means = 9.70 mg/dL, 95% confidence of difference = 6.30 mg/dL-13.10 mg/dL)
Figure 1. Average difference in blood glucose levels (milligrams/deciliter) 45 minutes after consumption of beverage. Mean difference in blood glucose levels with unsweetened water was 4.10 mg/dL (milligrams per deciliter) ± 0.66 mg/dL (±SE), N=10. Mean difference in blood glucose levels with table sugar-sweetened water was 14.10 mg/dL ± 1.37 mg/dL (±SE), N=10. Mean difference in blood glucose levels with sucralose-sweetened water was 4.40 mg/dL ± 0.58 mg/dL (±SE), N=10. There is a significant statistical difference in blood glucose levels with consumption of table sugar and consumption of sucralose (p=2.00*10-8, single factor ANOVA, Bonferroni Correction). Error bars are Mean ± SEM.
Discussion
The results convey a significant difference in the change in blood glucose levels when consuming sucrose (table sugar), and when consuming sucralose (Splenda®). The change in blood glucose levels with sucralose-sweetened water very closely resembled the change in blood glucose levels with unsweetened water. However, most blood glucose levels understandably decreased with the consumption of unsweetened water; for statistical purposes, the absolute value of these differences in blood glucose levels were taken. With sucralose-sweetened water, blood glucose levels only increased at an average of 4.4 mg/dl, which is significantly less than the mean increase in table sugar-sweetened water, 14.1 mg/dl. This mere partial increase in blood glucose levels after the consumption of sucralose is observed because the body digests and converts only a very small percentage of sucralose into glucose monomers. As shown below in Figure 2, sucrose and sucralose are very similar in chemical structure. For sucralose to be broken down into glucose monomers, the chlorine substituents must be removed. This would allow some of the sucralose to be digested as sucrose.
Figure 2. Chemical structure of sucrose and sucralose
Nino Binns of McNeil Nutritionals, LLC explains that on average, 15% of a dose of sucralose is absorbed and then rapidly excreted, with most of it remaining unchanged through urine (53). Of the 15% that is absorbed by the body, 2% of the ingested sucralose is removed through the urine in the form of glucuronide conjugates, inactive glycosides used by plants to store chemicals. Although ADME (absorption, distribution, metabolism, and excretion) studies have found sucralose to be poorly digested and mostly removed through feces, the slight increase in blood glucose levels with the consumption of sucralose cannot be overlooked. The notion that sucralose does slightly raise blood glucose levels provokes the question whether there is a form of chemical dechlorination occurring within the sucralose disaccharides. The possible chemical reaction that would occur at the atomic level would have to involve the substitution of the chloride substituents with hydroxyl groups, either by the SN1 or SN2 mechanism.
Because scientific studies claim sucralose does not hydrolyze or undergo dechlorination in any manner after ingestion, we must look to other sources to explain the increase in blood glucose levels with sucralose. It is possible to suggest that Splenda® artificial sweetener contains a small amount of sucrose that is not chlorinated during production of the product. However, the very small portion of unchlorinated sucrose should not have an effect on blood glucose levels as large as observed during the course of this experiment. Nevertheless, consuming sucralose is a much healthier and smarter choice than consuming regular table sugar, mainly because of the mitigated increase in blood sugar levels. Sucralose is safe to use in large amounts in foods, as the chlorine in the sweetener is not toxic. Also, sucralose is unaffected by the polarity of ethanol, which makes it a good sugar substitute for high calorie alcohols. And, from a dental standpoint, oral bacteria enzymes cannot break down sucralose, meaning that tooth decay is prevented.
Sucralose is a great choice for many people, as it is a sweet substitute to reduce caloric intake. Sucralose also assists diabetic people in coping with a lifestyle with limited sugar. Everyone should consider the long-term benefits of putting down the regular sugar and switching over to Splenda®.
Acknowledgements
We would like to thank Professor Steve Teh for his guidance and assistance throughout the project. We would also like to thank Dr. William Alston of the Chemistry Department for the knowledge he provided us with, and Saddleback College for the use of its facilities and equipment. Lastly, we thank our fellow students for their time and help with this project.
Literature Cited
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