Sucralose – Separating Fact from Fiction

There has been a debate over the safety of a new sugar substitute on the market, Sucralose a.k.a. Splenda®.  This paper is designed to help the reader better understand the arguments for and against this artificial sweetener.  Part of the debate will center on the article posted on the internet by at www.mercola.com.

Let’s look at some of the claims against sucralose first:

1. Shrunken thymus glands (up to 40% shrinkage)
2. Only 19 studies on the sweetener exist
3. Correlating sucralose to chlorinated pesticides
4. Absorption and metabolism of sucralose
5. High levels of contaminants
6. No post-approval monitoring

1. The problem with the claim that sucralose shrinks the thymus gland is when you read the study you find that “atrophy of the lymph follicles in the spleen and thymus was observed in the 50,000 ppm group.”  The ones fed sucralose at 10,000 and 25,000 ppm did not show this effect. Also, only one toxicologist, Judith Bellin, has disputed the manufacturer’s claims that the effect seen at 50,000 ppm was due to starvation and not from the sucralose. The evidence suggests starvation due to the high intake of sucralose by the laboratory animals.

2. This is blatantly misleading.  In the FDA Talk Paper of April 1, 1998 – T98-16, the paper says the following, “In determining the safety of sucralose, FDA reviewed data from more than 110 studies in humans and animals.”  To the websites credit, they do indicate that this was the number of studies determined by a MEDLINE search but the problem is that not all studies are reported through this manner so the information he uses is misleading. 

3. Comparing sucralose to chlorinated pesticides is a reach at best.  A number of PhD chemists we spoke to strongly disagreed with the connection between pesticides and sucralose.

4. There is a claim of high absorption of sucralose of up to 40%.  To begin with, since sucralose is 600 times sweeter than sugar, far less needs to be used to gain the same sweetening effect so if absorption is even as high as claimed the amount is miniscule. Second, the preponderance of the literature suggests that sucralose is not absorbed readily in the gut.  Most studies admit a 15% passive absorption of sucralose in the G.I. tract but one must remember the minute amounts being used to put this issue in perspective and that much of what has been absorbed is excreted in the urine unchanged. Some argue that intestinal bacteria in the gut (mostly pathogenic) metabolize sucralose but according to Farhadi A, et al, “bacteria metabolized lactulose and acidified the media but did not metabolize sucralose or mannitol.” 

5. The argument that high levels of contaminants were found in sucralose is somewhat misleading. The contaminants found in sucralose are similar to many foods we use without question.  We live in a contaminated environment which we believe is a major contributor to our many health problems, but you have to be realistic in the review of what is and is not significant. In a perfect world, there would be no need to use a sweetener, but we do not live in one.  When trying to mask the bitter and highly objectionable taste of an amino acid complex, compromises are necessary. After careful consideration and an honest review of the literature, sucralose seemed to be the safest and best choice.

The fact that sucralose is produced at an approximate purity of 98% and therefore the rest must be dangerous is conjecture also and a biased interpretation of the literature.  The added comment that, “Although manufacturing guidelines do specify limits on these substances there is no guarantee that such limits will always be met.” is a Chicken Little argument.  Not every manufacturer is evil and wanting to get away with something.  Yes, there are unscrupulous companies, especially when it comes to NutraSweet®, but you cannot make a linear correlation every time something new comes along.

6. The site argues that there is no post approval monitoring.  Curious that one of the links provided from the website, the Sucralose Toxicity Information Center, claims that “A possible problem with casecal enlargement and renal mineralization has been seen in post approval animal research.” (my italics)  There are currently numerous ongoing studies around the world being published on research relating to the potential harmful effects of sucralose.  This is another example of a misleading comment.  Baird IM, Shephard NW, Merritt RJ, Hildick-Smith G conducted a human study on different doses of sucralose and found no side effects after approval was granted. 

A Report from the Joint Subcommittee on Toxicity and Food Additives concerning the Designation of Food Additices and the Revision of Standards for Use under the Food Sanitation Council, January 6, 1999

Farhadi A, Keshavarzian A, Holmes EW, Fields J, Zhang L, Banan A., Gas chromatographic method for detection of urinary sucralose: application to the assessment of intestinal permeability., J Chromatogr B Analyt Technol Biomed Life Sci 2003 Jan 25;784(1):145-54

Baird IM, Shephard NW, Merritt RJ, Hildick-Smith G., Repeated dose study of sucralose tolerance in human subjects., Food Chem Toxicol 2000;38 Suppl 2:S123-9.