B3,RD: How safe are artificial sweeteners?

I know some of you have been wigging out waiting for this–so I’ll put you out of your misery.

Artificial sweeteners? Safe or the devil’s spawn? It’s a great question that’s racing through the minds of nutrition conscious people everywhere. Dietitians are divided in their thoughts. There’s the “I can’t live without my Diet Pepsi” crowd (many of my nutrition professors in our “Pepsi” school fit into this group), and there’s the “artificial sweeteners are going to be the end of Western civilization as we know it” crowd (although this crowd tends to not mind the end of Western civilization in other contexts).

Because this issue is such a divisive one–and one with so many different opinions–I’m going to give you the facts and my general recommendations, and then let you decide for yourself.

FDA Regulation of Food Additives

First of all, it’s important to be aware of how additives to our food supply (such as artificial sweeteners) are regulated. According to the rules of the 1958 amendment to the Food, Drugs, and Cosmetics Act of 1938, no chemical additive can be used in food if it has been “found to induce cancer in man…or in animals.” This means that, at least as far as cancer is concerned, we’re home free. If additives have been found to cause cancer in humans or in lab animals AT ANY LEVELS of exposure, they may not be used in the American food supply.

Once the additive has been determined to not cause cancer or other genetic changes, experiments are done to determine what levels of the additive are safe. Researchers find the highest “dose” that causes no observable health effects and then decrease that 100 times to determine the “Allowable Daily Intake” or “ADI”.

See the below table nabbed from the Mayo Clinic for more information on the ADIs.

You can see that the ADI limit for a 150 lb individual ranges from 6 to 30 cans of diet soda per day (for the rest of your life). Since ADIs are established at 100x LESS than the highest exposure at which no observable health effects can be noted–the actual “danger level” is somewhere around 600 to 3000 cans worth of diet soda per day. I think it’s safe to say that none of us consume that much artificial sweetener.

So, based on FDA regulations, artificial sweeteners are safe for use at the levels in which they are present in the food system.

The National Cancer Institute on Artificial Sweeteners

According to the National Cancer Institute’s fact sheet on artificial sweeteners, “there is no clear evidence that the artificial sweeteners available commercially in the United States are associated with cancer risk in humans.”

A few studies suggest correlations between artificial sweeteners and cancer risk, but these studies are generally poorly designed. It is unclear whether the vague results of these studies have any applicability. For example, a study suggested that national brain cancer rates rose as a result of the introduction of aspartame. However, the trend in rising rates began 8 years prior to the introduction of aspartame and occurred in a population unlikely to consume aspartame.

The American Dietetic Association (ADA) on Artificial Sweeteners

According to the ADA Evidence Analysis Library (which compiles and evaluates all of the best research on nutritional topics), “Limited research in humans, from peer reviewed journals, supports the safety of non-nutritive sweeteners for the general population. Considering the lack of high quality studies, continuing post-market surveillance of the safety of non-nutritive sweeteners is prudent.”

The phraseology is a bit bulky (that’s what happens when committees write a recommendation), but the gist is as such: “We don’t have a lot of good research in humans, but what we do have says that non-nutritive sweeteners are safe for the general population. However, since there isn’t a lot of good research available, we should continue watching for evidence one way or the other.”

How’s that for equivocation?

My opinion on the safety of artificial sweeteners

My opinion falls somewhere between the FDA’s “of course they’re safe”, the National Cancer Institute’s “all the studies that say they aren’t are flawed,” and ADA’s “we can’t really tell.”

I think that it is safe to believe that artificial sweeteners are unlikely to cause cancer. Because of the restrictions of the 1958 Delaney Clause, the FDA is required to conduct a great deal of research on the carcinogenic properties of potential food additives prior to approving them. The National Cancer Institute concurs that the artificial sweeteners that have been approved by FDA are unlikely to cause cancer.

However, only a limited body of research exists in other non-cancer areas of health. There are big blank holes in the research.

We do know, based on other chemicals, that most substances have dose-dependent responses. Even the best of things, when consumed in excess, can be toxic. Much of the nation was startled to learn of water intoxication in 2002 when Cassandra Killpack died after being force-fed excess quantities of water by her adoptive parents. Even water, the chemical most essential for life, is toxic in large quantities. On the other hand, in low doses, many potential toxic chemicals have little effect.

It makes sense that we should control the DOSES of artificial sweeteners that we consume. If you are close to or above the FDA ADIs, you might consider backing off on the artificial sweeteners.

Also, since children have lower body weights, they are more susceptible to overdosing on anything–so it makes sense to watch children’s intake more carefully. Pregnant and lactating mothers may want to watch their intake more carefully as well, as we do not know what effect any artificial sweeteners might have on rapidly growing babies.

So, my general recommendation, is that artificial sweeteners are likely to be safe when consumed in moderation. As a quick rule of thumb, I would say that if you are consuming more than three servings of foods made with artificial sweeteners (half the ADI for Splenda for a 150 lb individual), you might want to back off. But if you’re consuming less than three servings of artificial sweeteners in a day, the benefit of consuming fewer calories is probably greater than the risk of some unknown health issue.

Your B3,RD challenge for today (although today is nearing its end–sorry folks, this one took longer than I expected) is to calculate up approximately how much artificial sweetener you consume in an average day. Do you top my recommendations? How about the FDA’s?