Did You Know Aspartame Can Make You Have Incontinence?

Aspartame is an artificial sweetener used in many beverages today, including diet sodas and zero-calorie flavored waters. It is also found in some diet, low sugar alternative foods. Furthermore, it is used in many medications.

Most consumers may have some realization about the health risks of ingesting artificial sweeteners, but they may not realize that artificial sweeteners, such as aspartame and even splenda (to a lesser degree), can irritate the bladder and lead to bladder urgency incontinence. In fact, a person who consumes more than one 12 ounce beverage with aspartame increases the risk of bladder irritation.  Additionally, if that same person also eats many diet foods with artificial sweeteners, they are increasing their risk significantly.

Some studies have shown that aspartame turns into formaldehyde in the body, so you can imagine the many negative health risks a person undertakes while consuming aspartame.

Many patients who suffer from bladder urgency are “cured” after they omit aspartame from their diet. Healthier alternatives are stevia and agave. The healthiest choice of all, is of course, drinking 6-8 eight ounce glasses of water per day.

Here is to drinking to better bladder health!



  1. John E. Garst, Ph.D. (Medicinal Chemistry, Pharmacology, Toxicology, and Nutrition)

    This article reflects sensationalistic journalism. Now over 100 regulatory agencies have independently shown that aspartame is perfectly safe used as directed in healthy people. There is one reference even bladder related and it was achieved in isolated muscle samples, http://www.ncbi.nlm.nih.gov/pubmed/17046038. Such results are far removed from human incontinence! Such studies have little real world relevance to risk assessment. And this is especially true for aspartame, which is completely destroyed, before even being absorbed as its three constituents. Phenylalanine and aspartate are found in greater concentrations in normal foods, like milk and meat. Only methanol amongst aspartame degradation products presents any risk to normal people and, since all risk is dose-dependent, it presents NO risk at the concentrations involved. Methanol is oxidized to formaldehyde and formate–both are chemically directly converted by the (tetrahydro)folate vitamin system into very valuable methyl groups. These substances and the methyl groups produced detoxify really toxic homocysteine (see Wikipedia) and protect DNA (thymine). For more on this cycle see the figure at the top of p 3000 here, http://download.cell.com/AJHG/pdf/PIIS0002929707614001.pdf?intermediate=true

    Formate and formaldehyde are [quoting another] “produced in the body during the endogenous demethylation of many compounds, including many foods and drugs. For example, the demethylation of the caffeine found in one cup of coffee produces 30 mg of formaldehyde (Imbus, 1988). Formaldehyde is essential in one-carbon pool intermediary metabolism. The metabolite of formaldehyde, formic acid, is a substrate for purine nucleotide synthesis (Sheehan and Tully, 1983). It can be calculated that more than 50,000 mg [that’s 50 g] of formaldehyde is produced and metabolized in an adult human body daily and that an adult human liver will metabolize 22 mg of formaldehyde per minute (Clary and Sullivan, 1999). Consequently, it is quite clear that the formaldehyde from aspartame provides a trivial contribution to total formaldehyde exposure and metabolism in the body” (p 18 in and refs from http://www.fte.ugent.be/vlaz/Magnuson2007.pdf).

    Do these facts not make clear that any perceived problem is not with aspartame, methanol, formaldehyde or even formate, but personal metabolism issues in detoxifying them? With folate, homocysteine and B12, see that cited p 3000) these are potentially numerous. Many people are deficient in vitamins and up to 40-50 % of some S. European populations have folate polymorphisms that require even more folate, but most don’t even know it. It is very uncommon to even test for this. For more read http://download.cell.com/AJHG/pdf/PIIS0002929707614001.pdf?intermediate=true. And that doesn’t include people with high blood concentrations of the true excitotoxin homocysteine or low concentrations of vitamin B12 (again see that figure on p 3000).

    Now to short-circuit your premise further, note that the only relevant reference (second line) could totally be explained by homocysteine, which accrues with folate deficiency and would accrue given direct application of aspartame without the suitable methanol rather than water control, a fact supported by this citation, http://www.ncbi.nlm.nih.gov/pubmed/19508427.

    John E. Garst, Ph.D. (Medicinal Chemistry, Pharmacology, Toxicology, and Nutrition)

  2. Thank you for your comment.
    It should be made clear, that the title of the blog includes one operative word that clearly is supported by numerous journal articles, some of which have been included below. That word is “Can.” Aspartame can cause bladder urgency (by causing spasms of the detrusor muscle of the bladder, which signals a person to empty more often than normal), which can lead to urgency incontinence. However, aspartame ingestion does not always lead to incontinence, because not everyone has difficulty digesting aspartame.

    You bring up an excellent point, that people who have problems with metabolizing may be affected more by aspartame, methanol, formaldehyde, etc. than people with no metabolic dysfunction. I agree. Perhaps it could be pondered whether or not the presence of such chemicals in the body can, over a period of time, lead to a metabolic dysfunction. Consequently, is it truly a dysfunction of the human body to have difficulty metabolizing a man-made chemical that normally wouldn’t have been ingested if it weren’t invented? Or is it (metabolic dysfunction) the body’s way of expressing the impact of such chemical ingestion/invasion?

    Please read these articles and let me know what you think. Thanks.

    1. Int J Clin Pract. 2011 October; 65(10): 1026–1036.
    doi: 10.1111/j.1742-1241.2011.02763.x. A healthy bladder: a consensus statement.
    According to a panel of experts in urogynecology, urology, behavioral therapy, and nursing, artificial sweeteners, including aspartame, are included on the list of bladder dietary irritants and are recommended to limit/modify as part of a normal, healthy diet to avoid urinary bladder urgency and urgency incontinence.

    2. http://www.nafc.org/bladder-bowel-health/types-of-incontinence/urge-incontinence/

    ” Artificial sweeteners (sodium saccharine, acesulfame K, and to a lesser degree aspartame) have been shown in limited studies to negatively affect bladder function. In research, episodes of daytime frequency of urination, urgency, and nocturia all increased with the consumption of dietary beverages compared to drinks with sugar or unsweetened. ” (this information found at above website)

    3. Current Urology Reports. Volume 10, Number 6 (2009), 428-433, DOI: 10.1007/s11934-009-0068-x. Management of fluid intake in patients with overactive bladder. Hashim Hashim and Riyad Al Mousa.
    Found at http://www.springerlink.com/content/e257x8j4734t3846/

    Quoted in this report: “Decreasing caffeine intake and artificial sweeteners may also help with symptoms improvement…..”

    4. http://www.sciencedirect.com/science/article/pii/S0041008X06003061

    Toxicology and Applied Pharmacology. Volume 217, Issue 2, 1 December 2006, Pages 216–224. Enhancement of rat bladder contraction by artificial sweeteners via increased extracellular Ca2+ influx. Jaydip Dasgupta, Ruth A. Elliott, Angie Doshani, Douglas G. Tincello

    Note: The overall results showed increased bladder contractions (detrusor overactivity) with presence of artificial sweeteners, including aspartame.

    5. http://onlinelibrary.wiley.com/doi/10.1111/j.1742-1241.2009.02078.x/full
    The International Journal of Clinical Practice. Practical aspects of lifestyle modifications and behavioural interventions in the treatment of overactive bladder and urgency urinary incontinence. J. F. Wyman1, K. L. Burgio2, D. K. Newman3. e 63, Issue 8, pages 1177–1191, August 2009. Article first published online: 2 JUL 2009

    Quoted from article: “… There is also evidence to suggest that aspartame and other artificial sweeteners induce detrusor contraction in …”

    6. Journal of Wound, Ostomy & Continence Nursing: November 1996 – Volume 23 – Issue 6 >
    Noninvasive Techniques to Manage Urinary Incontinence Among Care-Dependent Persons. Colling, Joyce RN, PhD, FAAN.

    Quoted: ” … Beverages containing artificial sweeteners such as aspartame (Nutrasweet) should be used on a limited basis because they can irritate the bladder, making urine
    control more difficult. Inadequate fluid can also irritate the bladder, causing urgen

    7. Journal of Wound, Ostomy & Continence Nursing: May/June 2005 – Volume 32 – Issue 3S – p S11-s15. Behavioral Interventions for the Patient With Overactive Bladder. Wyman, Jean F.

    Quoted: “…Modify the diet to reduce bladder irritants, such as carbonated beverages, artificial sweeteners (particularly aspartame … goals of bladder training are to correct faulty habit patterns of frequent urination (if present); improve control over bladder urgency; prolong voiding …”

    Observing patients improve on bladder urgency symptoms after eliminating or limiting bladder dietary irritants, including aspartame, confirms what the research listed above states. Recommending to patients to decrease bladder irritants, including aspartame, is standard practice in pelvic floor therapy with observable improvement on many of those individuals who comply.

  3. John E. Garst, Ph.D. (Medicinal Chemistry, Pharmacology, Toxicology, and Nutrition)

    Gina thanks for writing back and allowing me to address your ‘CAN’ issue. You provide a likely-comprehensive literature list of claims/accusations associating aspartame bladder issues. I do not for a minute deny their existence. But in citing all these, you missed my point. Such allegations are simply anecdotal reports. That some physician believes aspartame (or many other listed substances) may affect a bladder issue is not what I question. I question the health of the physician’s patient, which is never examined (and will be addressed again in my last paragraph). Physicians never make any effort to understand the patient’s metabolism and for that reason they never provide the appropriate controls that would instantly exclude aspartame, caffeine, fruit juice, etc. as causes. Physicians blindly see an association with these substances, as noted in your citation 1 and then quote it like gospel. Were you aware that most juices contain polymeric galacturonic acid methyl esters (pectins, Wikipedia)? They release methanol upon gastric hydrolysis or lower gut processing? So as I tried to get across to you in my response, aspartame is not the problem, instead the problem is the patient’s underlying health that the physician in your citations is treating. Recall the relative amounts of formaldehyde generated from caffeine and aspartame in my “Formate and formaldehyde are…” paragraph. By noting these other substances these physicians unknowingly are acknowledging exactly my point—sensitivity to aspartame reflects not aspartame per se, but some underlying problem with their patient’s personal metabolic systems.

    The gist of my response is that you say CAN, I say CANNOT, because aspartame itself cannot cause any such issues in people having adequate nutrition. It is these or other genetic issues that are associated with accrual of homocysteine, a true excitotoxin (see Wikipedia). A major problem is that physicians simply never consider the underlying issue, but folate necessity for aspartame metabolism has been well-documented for over twenty years by Tephly, http://www.ncbi.nlm.nih.gov/pubmed/1997785. Folate deficiency, folate polymorphisms (that require more folate), vitamin B12 deficiency, and/or homocysteine accrual in their patients (or for that matter isolated muscle lab experiments) completely and totally explains every such sensitivity case. I have yet to see any case not fit. However, one cannot rule out yet other nutritional issues, as has also been done for overactive bladder, http://www.ncbi.nlm.nih.gov/pubmed/15098215.

    But overall, in people with personal sensitivity to aspartame, these adverse risks exist whether one uses aspartame or not. Widespread overindulgence in ethanol (acetaldehyde is an inhibitor of the folate reactions) only exacerbates these risks, just as ethanol is known to exacerbate breast and other cancers and facilitate fetal alcohol syndrome. And as noted in today’s USA Today (Sep 25, 2012, p) 51.8% of the population use ethanol. Combine that with 40-50% of S. European populations having folate polymorphisms (cited in my original post) and you have a public health crisis that has absolutely nothing to do with aspartame.

    I tried to make this point before, but you must have missed it, so let me restate that your response citation 4 was my first point, which I completely countered with my very last citation noting that homocysteine can kill cells through “resultant Ca2+ influx” exactly as was suggested to occur in your citation 4 (my original post citation 1). It is homocysteine accrual, not aspartame that explains that paper completely. See it is not just physicians but scientists who often just don’t understand they are simply using the wrong control. You cannot apply aspartame and compare its action against a water based-control, because you cannot deplete a vitamin and that is exactly what aspartame alone is doing. Any such experiment must be measured against an equal amount of methanol as aspartame control, because methanol itself, especially with isolated tissues, will deplete folate, albeit not by much, but just enough to cause their results. This means folate drops and homocysteine will rise in uncontrolled fashion just due to the experimental setting, not to reality. This means many, many such studies are simply invalid, and amongst those are all rat studies using prolonged treatment times.

    In a final point noting the importance of these vitamins and homocysteine, I provide citation http://www.ncbi.nlm.nih.gov/pubmed/11835426, titled “Neurological signs are common in patients with urodynamically verified “idiopathic” bladder overactivity.” In their results section they note “in 37 of the 45 patients (82%) pathological signs were observed in the neurological tests (Table II), the rest being normal. The most common finding was central or peripheral paresis of the legs, present in 24 patients (53%). Reduced vibration sense in the legs was a common sign (Table II) and three of these patients had a low value of vitamin B12 in serum.”….. ”Of the 45 patients, eight were diagnosed with a neurological disease, definite or possible MS, or dorsal column sensation neuropathy, as a result of the physical examination and blood and CSF testing (Table II).” This report is even more interesting because of the high correlation between homocysteine,multiple sclerosis (41) or B12,multiple sclerosis (92 papers) compared to none documenting (one alleging, not counted) the same association with aspartame, multiple sclerosis.

    As implied some critics claim aspartame causes MS, but again it is not aspartame, but the underlying personal health that is an issue. And realize MS has been around far longer than aspartame. Many widely used drugs affect/deplete folate besides ethanol and that includes ibuprofen, most antiepileptic and many other drugs. And no matter how healthy one might eat, one simply cannot get enough dietary folate. Supplements are required; that is why folate is a vitamin needing replenishment daily. B12 deficiency is often associated with vegetarianism. Given its high association with MS, perhaps MS is associated with vegetarianism?

    Lastly, Gina, please reread my “Formate and formaldehyde are…” paragraph. Contrary to your statement, it cannot be pondered, provided folate and B12 are adequate. As noted, given adequate vitamins, we turnover about 50g (that is grams) a day of these substances and that turnover is fast—formaldehyde is metabolized at the rate of 22 mg per minute (one can of aspartame sweetened beverage per minute). Everything about aspartame really is not about the safety of aspartame or caffeine or even fruit juice (which contains methanol too), but the personal availability of these vitamins and accrual of homocysteine.

    John E. Garst, Ph.D. (Medicinal Chemistry, Pharmacology, Toxicology, and Nutrition)

  4. Gina Jay

    Let’s agree to disagree on my choice of semantics. I am actually agreeing with you that metabolic dysfunction is most likely the cause of bladder urgency with certain foods. Yeah, it makes sense vitamin deficiency causes a lot of problems in the human body. (We can appreciate the outcome of vitamin deficiency and its affect on multiple systems in the body when we look at Celiac Disease – a malabsorption disease.) And probably most of the patients I work with have some kind of issue with vitamin deficiency or metabolic dysfunction, since these indiviudals are being treated at the tertiary level of care, disease already present. More uncommonly, do I have the pleasure of treating someone in the primary, preventative realm. (The PT profession is definitely hoping to do more prevention education.)

    When it is observed in the clinic that an individual improves with urgency incontinence symptoms off of aspartame, then it is reasonable to conclude that the individual who is doing better without ingesting aspartame, should limit that particular food in his or her diet. This concept is based on food elimination diet trials.

    Coming from a physical therapist perspective, many of the indiviudals seen in the clinic have diseases and if they do have metabolic dysfunction, I am not the healthcare worker that can investigate that further and try to change it, if possible. Usually these patients are on all kinds of medications. Perhaps they should be referred to a holistic nutritionist to discern the underlying issues in regards to food metabolism, looking at vitamin deficiencies, etc. Is this something you do?