It’s been a fair while since my last proper science post largely because they’re a bit harder to throw together than a cute kid or cheesy dad story or opinionated rant. But after the last Science Tuesday post that I wrote on autism, I got my first request. Not Afraid To Use It suggested that I take a look at artificial sweeteners, specifically Splenda. Not being used to getting requests, I was flattered and happy to oblige.

The science surrounding non-nutritive artificial sweeteners is interesting and contentious. Most official bodies have declared the common artificial sweeteners on the market to be “safe”. Medical organizations recognize the dietary advantage of artificial sweeteners. Human beings are born with a sweet tooth and a lot of dieticians and nutritionists recognize that artificial sweeteners can promote diet healthfulness by serving as a substitute for sugar.

There are five artificial sweeteners that have been approved for use in the U.S.A. by the F.D.A. as additives - saccharin (Sweet ‘N’ Low), acesulfame-K (Sunnett), aspartame (NutraSweet), cyclamate (Sugar Twin) and sucralose (Splenda). FDA approval generally assesses toxicity of the compound, mutagenicity, carcinogenicity and reproductive toxicity (ADA). The FDA decision is based on studies carried out, often by the company or organization that is requesting approval. Many of these studies are not available to consumers. This is where the problems come up with drugs and foods that turn out to be poison - the lack of independent verification of the claims presented to the FDA. Increasingly in the FDA approval process, the companies that produce food additives have the power; lobbying money well spent. For example, many of you will remember the cancer scare surrounding saccharin in the late 1970’s This stemmed from a couple of reports associating heavy saccharin consumption to bladder cancers in rats. The FDA proposed a ban on saccharin in 1977, a ban which was overturned by Congress under heavy pressure from lobbyists.

One of the most entertaining things that I learned about sweeteners was the serendipitous way in which many of them were discovered (Whitehouse, et al.). Now, I worked in labs for nearly a decade and not once did I think it would be a good idea to taste what I was working on. But saccharin, aspartame and acesulfame-K were all discovered when scientists licked their fingers after accidentally splashing something on them. (Yum, that chemical tastes like diet soda). Even better is the story of the discovery of sucralose. Apparently a Ph.D. student misunderstood his supervisor’s request that he “test” the compound on which he was working. Boss said “test”, student heard “taste”. I’ve heard of some odd Ph.D. supervisors, but I might rethink things if my boss suggested that I orally assess my experiment.

To the matter at hand – there is a fair bit of uncertainty regarding the safety of sweeteners. Because they have been approved by the FDA, the general public considers them to be completely safe. Fair assumption that your government has your safety as its top priority, eh? However, there are a number of reports in the scientific literature that would urge a bit of caution regarding the use of some of these substances. This uncertainty is due to the FDA’s almost complete reliance on private studies undertaken by the companies seeking approval for their products. Let’s take a look at some of the issues surrounding popular sweeteners.

Saccharin

The oldest of the sweeteners seems to be the safest. The studies linking saccharin to cancer back in the 70’s involved rats that were fed diets containing 5 – 7.5% saccharin. It would be virtually impossible to consume this much saccharin in your diet. This is the reason that saccharin was ultimately deemed to be safe. One disturbing study published in the New England Journal of Medicine in 1994 did find that drugs with a low level of saccharin as a flavoring agent were associated with liver damage, but this was in a very small sample of people (Negro, et al.). However, saccharin is not used as commonly as it was prior to the 1990’s due to its distinctive and unpleasant aftertaste.

Aspartame

The sweetener used in Nutrasweet or Equal is the most suspicious of the artificial sweeteners. Since gaining approval as a general-purpose sweetener in 1996 there have been peer-reviewed studies linking aspartame to pediatric and adolescent migraines, insomnia, seizures, Alzheimer’s and other brain pathologies, urinary tract tumours, lymphomas and leukemia. A number of these studies are controversial and for this reason aspartame maintains FDA approval and is found in numerous sugar-free or reduced sugar products. In fact, the level of disagreement within the scientific community about the safety of aspartame is intense. It’s hard for me to distill what’s really going on as almost every peer-reviewed study showing harmful effects of aspartame use is disputed by another scientist. Seems to be a pretty contentious field.

But there are a few studies in particular that are troubling. Particularly ones that looks at harmful effects of aspartame at a reasonable dietary level. Some of these are troubling to the point that I’m going to keep the boy away from the stuff. In one study, Italian researchers found that in utero exposure to low levels of saccharin a significant increase in incidence of lymphomas and leukemias in rats. (Soffritti et al.). A Hungarian group looked at expression of oncogenes in mice dosed with FDA appproved levels of aspartame and found that expression was increased. Oncogenes are genes which, when deregulated, are associated with the onset of cancer. So, aspartame is associated with an increase in expression of genes that, when expression is increased too much, can induce cancer (Gombos et al.).  This kind of biology isn’t my field, but in my opinion, researchers are beginning to put together a fairly convincing picture regarding the carcinogenicity of aspartame.

Sucralose

Splendid Splenda is the new kid on the sweetener block and thus there is less research available regarding potential health risks. Initially, there were concerns about reports that excessive sucralose consumption caused shrunken thymus glands. However, it was later determined that this effect was due to a very low calorie diet rather than sucralose itself. There have been a couple of reports that link sucralose with migraines, but even these are fairly controversial. There were some concerns that ingredients that sucralose is often bulked with may cause cavities, but it was found that the cavity causing potential of these was less than sugar. So, NATUI, as far as I can tell you can go Splenda crazy.

As for the other sweeteners, cyclamate, acesulfame-K and neotame, there aren’t a lot of studies looking at these. The scientific community seems to have cleared cylcamate’s name but would like to see further research on neotame and acesulfame-K.

Part of the reason that the potential toxicity of sweeteners is so controversial is that the medical establishment believes that because obesity rates have increased globally, the benefits of sweetener in reducing food energy intake outweigh their potential harmful effects. In other words, the health problems that can be induced by obesity are far worse than potential harmful effects from artificial sweeteners. Therefore, it is better for people to have access to low calorie foods whenever possible. For example, the American Dietetic Association, while acknowledging some studies linking sweeteners to cancer, migraines and other health problems, believes “that consumers can safely enjoy a range of sweeteners when consumed in a diet that is guided by current federal nutrition recommendations (ADA).”

Unfortunately, low sugar or sugar-free food and drinks may not actually help that much in terms of our obesity epidemic. Another factor to consider is that artificial sweeteners may actually contribute to weight gain. A recent study suggested that low-calorie sweeteners may actually increase appetite for sweet foods, promote overeating, and lead to weight gain (Bellisle and Drewnowski). Other reports have been published that support this theory, demonstrating that artificial sweeteners blunt the body’s energy expenditure mechanisms and activate taste pathways differently than sugar. In other words, a Coke Zero diet is probably not going to help you with your weight and may cause more serious health risks.

———————–
The White Stripes’ self titled album is available from  The White Stripes - The White Stripes.

Photos:

Sweetener packets

Pouring sweetener

Diet sodas

 
icon for podpress  The White Stripes - "Sugar Never Tasted So Good" [2:55m]: Play Now | Play in Popup | Download

Popularity: 34% [?]