Aspartame: 11 Dangers of This All-Too-Common Food Additive

March 16, 2018
Aspartame - Dr. Axe

Few food additives have been studied with such scrutiny — or with more controversy — than that of aspartame.

Proponents of diet drinks claim that no adverse effects have been proven and that aspartame-laced products contribute to weight loss. On the other side of the coin, a large community of health-conscious, anti-aspartame health practitioners and consumers are convinced the U.S. Food and Drug Administration has turned a blind eye to one of the most dangerous food additives ever discovered.

Not to give away the ending here, but you’ll find me 100 percent in that second camp of people. Aspartame is one of the worst artificial sweeteners you can ingest and has been associated with dozens of potential health risks.

The sweetener industry received a blow when a study was released in July 2017 connecting aspartame to an increased risk of heart disease and increased body mass index. Far from the small studies that are sometimes dismissed, this review included a total of almost 407,000 individuals with a median 10-year follow-up. (1)

Researchers discovered that there were not only no benefits from consuming “diet” foods and drinks containing these artificial sweeteners (known as “non-nutritive sweeteners,” since they offer no calories), but those were associated with “increases in weight and waist circumference, and higher incidence of obesity, hypertension, metabolic syndrome, type 2 diabetes and cardiovascular events.”

Of course, a few smaller cohort studies did find weight loss to be a benefit — but, as is the norm for aspartame research, those were sponsored by industries benefiting from positive outcomes.

Do aspartame-sweetened products help you lose weight? No. Is aspartame safe? No. Does aspartame cause negative, sometimes dangerous side effects? Yes, absolutely. So let’s explore more about this dangerous food additive, how it came about and why you should stay away from it.

What Is Aspartame?

To understand why aspartame causes side effects, it’s important to first explain what it is and how it metabolizes when you drink or eat it.

What is aspartame made of?

Aspartame is an artificial sweetener, also referred to as Acesulfame potassium (K), AminoSweet®, Neotame®, Equal®, NutraSweet®, Blue Zero Calorie Sweetener Packets™, Advantame®, NutraSweet New Pink, Canderel®, Pal Sweet Diet®, and AminoSweet®, and it’s used in a variety of food and wellness products like diet soda, gum, candy and vitamins.

Almost immediately upon consuming aspartame, it breaks down into three chemical compounds: phenylalanine, aspartic acid, and methanol. (2)

Those first two components are amino acids. Methanol is known as “wood alcohol” and is known to be toxic in large doses, but the amount of methanol in one can of diet soda is about the same that naturally occurs in, say, a glass of grape juice.

Sounds safe, right? After all, don’t we need amino acids to survive? And methanol can’t be that bad if it’s in grape juice, too, can it?

Sadly, these arguments, used widely by companies that profit from the sale of aspartame, do not hold up.

Phenylalanine is an amino acid that can be toxic in high doses but generally recognized as safe in whole food products. However, when chemically bound to other compounds, like in aspartame, phenylalanine is absorbed almost immediately into the bloodstream rather than slowly via digestion.

Since this amino acid can cross the blood/brain barrier and functions as an excitotoxin when absorbed too quickly, it may potentially conflict with various neuronal processes. Just one diet soda raises the level of phenylalanine in the brain, causing serotonin levels to decrease. (3)

In at least one study, phenylalanine concentrations were higher in people with HIV, sepsis, cancer and undergoing trauma. (4)

Aspartic acid is a non-essential amino acid (your body makes it without having to ingest it). Normally, aspartic acid (aspartate) is important in the function of the nervous and neuroendocrine systems. (5)

Methanol is a wood alcohol that was not commonly ingested until the 20th century. It has no health benefits, but it’s particularly dangerous when consumed in aspartame.

How does the body process aspartame?

As I’ve pointed out, there is some concern about the way the body metabolizes the two amino acids from aspartame. Because of the way diet soda and other aspartame products are created, the amino acids they contain do not go through the normal process of enzyme breakdown and liberation, but instead absorb immediately into the bloodstream.

However, the more pressing concern comes from the methanol content in aspartame. Now, it is true that methanol is present in other food products, but in those cases, it is bound to pectin, a fiber commonly found in fruits. Generally, these bound pectin/methanol compounds are excreted safely through the normal digestive process.

In aspartame, methanol is bound (weakly, at that) to the phenylalanine molecule. One or two processes easily break that bond and create what is known as “free methanol.” In cases where the aspartame product has been kept in a hot environment over 85 degrees Fahrenheit (like a warehouse or hot truck), the bonds decompose before ever entering the body.

Free methanol then converts to formaldehyde, more commonly known as embalming fluid. Both methanol and formaldehyde are carcinogens in and of themselves. Formaldehyde has the unfortunate ability to cross the blood-brain barrier, one reason it is so detrimental to the body. Eventually, the formaldehyde can also turn into diketopiperazine, another known carcinogen.

Every animal other than humans converts formaldehyde to formic acid, a harmless substance. But humans don’t have the necessary enzyme for that change, which is one possible reason why animal studies don’t always represent the extent to which methanol impacts the body. This process in humans is called methyl alcohol syndrome. (6)

What now?

As you probably know, aspartame in diet soda and over 6,000 other products is still approved by the FDA after decades of research and adverse reactions. The FDA even encourages pregnant women to drink it!

One estimate created in 1996 for sufferers of aspartame symptoms calculated approximately 1.9 million recognized toxic reactions between 1982 and 1995. This number is complicated by the fact that many doctors do not recognize aspartame toxicity as a legitimate cause of health problems since it is supposedly a safe product for all people. (7)

As of 1995, the list of reported symptoms submitted to the FDA included headaches, dizziness, mood problems, vomiting, abdominal pain and diarrhea, seizures, memory loss, breathing problems, and various others. (8)

Aspartame (now owned by Ajinomoto) is now being marketed under new names in order to further mislead consumers. (9)

This has occurred even after aspartame poisoning has been implicated in the development of Gulf War syndrome, a number of neurological and physical symptoms of veterans in the U.K. and U.S. Gulf War. Troops were given large quantities of diet soft drinks that had often been in high-temperature conditions, suggesting they had already broken down into free methanol and formaldehyde compounds before they were consumed.

Still, we are told by agencies designed to protect us that aspartame is safe for people of all ages. The only exception to this is those suffering from the rare disease phenylketonuria, a birth defect that disrupts the body’s ability to process phenylalanine.

Products that Contain Aspartame

Aspartame is found in over 6,000 individual products, making it virtually impossible to list them all here. However, I hope that understanding the impact of nutrition on your health has made you an avid label-reader. If you consider purchasing any of the following types of items, check the label — you’re likely to find aspartame listed.

The following foods, beverages and medications commonly contain aspartame: (10, 11)

  • Diet soda
  • Sugar-free breath mints
  • Sugar-free (or “no sugar added”) cereals
  • Sugar-free (or “no sugar added”) condiments
  • Flavored coffee syrups
  • Flavored water
  • Sugar-free ice cream and/or toppings
  • Diet iced tea products
  • Low-sugar or sugar-free fruit juices
  • Meal replacement shakes/snacks
  • “Nutrition” bars
  • Sports drinks (especially “sugar-free” varieties)
  • Soft candy chews
  • Yogurt (sugar-free, fat-free and some drinkable brands)
  • Vegetable juice drinks
  • Natural fiber laxative
  • Fiber oral powder supplements
  • Appetite control supplements


Aspartame products - Dr. Axe


11 Dangers of Aspartame

In 2002, anti-aspartame activist Mark Gold reviewed aspartame toxicity results and reported them to the FDA for consideration. Individual complaints included some 49 symptoms, including headaches (reported by 45 percent of people), severe depression (25 percent), grand mal seizures (15 percent) and confusion/memory loss (29 percent).

Gold also referred to dozens of studies reflecting the negative impacts of aspartame, including the many warnings in piloting material to discourage pilots from consuming it due to the seizures and vertigo it can induce. (12)

It seems that the dangers studied occur very differently in participants depending on who completes the study. For example, one review claims there to be “no unresolved questions regarding [aspartame’s] safety.” (13)

Of course, that particular report was released by NutraSweet. Let’s not just take their word for it.

Turns out, 100 percent of industry-funded research finds the same result: that aspartame is totally safe. However, 92 percent of studies funded independently discover adverse effects. (14)

The Ramazzini Institute, a longtime cancer research center, has studied aspartame at length and claimed again in 2014 in the American Journal of Industrial Medicine, “On the basis of the evidence of the potential carcinogenic effects of [aspartame] herein reported, a re-evaluation of the current position of international regulatory agencies must be considered an urgent matter of public health.” (15)

So, what are the most serious dangers of aspartame?

1. Potentially Increases Risk of Cancer

For decades, studies have proved the potential carcinogenic qualities of aspartame. The Ramazzini Institute continues to stand behind the results of its multiple studies finding aspartame to be associated with a 300 percent increase in lymphoma/leukemia incidence, even after being dismissed by the European Food Safety Authority. (16)

A Ramazzini study shows a correlation between aspartame and various cancers to the degree that the organization refers to it as a “multipotential carcinogenic agent,” even in doses well below the legal “acceptable” amounts. (17)

One reason this 20-year study is so significant is because the rats involved in the research were allowed to die naturally rather than being sacrificed earlier in the experiment. This was to investigate the last two-thirds of the animal life span, often unaccounted for, because cancer occurs in humans most often during this portion of life.

Overall, studies have discovered links between aspartame and the following cancers: (18, 19, 20)

  • Liver cancer
  • Lung cancer
  • Brain cancer
  • Breast cancer
  • Prostate cancer
  • Central nervous system cancers (gliomas, medulloblastomas and meningiomas)

The discovery of the central nervous system cancers seems to be associated with the behaviors of the two amino acids found in aspartame because they are consumed in such large amounts and not broken down in the same fashion as when ingested in other foods and their ability to cross the blood-brain barrier. This allows their excitotoxicity to take full effect.

Cancer incidence seems to increase when animals are exposed to aspartame in the womb, underlining the importance for pregnant mothers never to consume aspartame. (21)

Formaldehyde (a metabolite of free methanol) is associated with the development of breast, stomach, intestinal, lymphoma and leukemia cancers.

2. Might Induce or Worsen Diabetes

Although doctors often recommend replacing sugary drinks with diet versions for diabetics, aspartame seems to have the opposite effect than hoped.

Diet soda consumption is associated with a higher risk of Type II diabetes as well as metabolic syndrome, a cluster of symptoms indicative of heart disease (which I’ll touch on in a moment). In fact, in this study of over 6,800 individuals of varying ethnicity between 45–84 years old, the risk of diabetes was 67 percent higher for people who consumed diet soda daily versus those who did not. (22)

It seems, in many cases, that aspartame intake can also aggravate diabetes symptoms, such as diabetic retinopathy and diabetic neuropathy.

Aspartame conflicts with insulin/glucose tolerance, a marker of prediabetes, especially for those who are already obese. (23) One suggestion why is the way aspartame alters gut microbiota (healthy bacteria) — these changes can induce glucose intolerance in otherwise healthy people. (24)

An animal study in December 2016 suggests a connection between an interaction between aspartic acid found in aspartame and glucose management. This, again, is exacerbated by the way this amino acid passes the blood-brain barrier. Researchers also discovered behavioral deficits in the subjects. (25)

3. Could Increase Risk of Heart Disease and Stroke

As I just mentioned, aspartame intake is associated with metabolic syndrome. This cluster of conditions includes high blood pressure, high blood sugar, excess belly fat and high cholesterol/triglyceride levels, and marks a dramatic increase in the risk for heart disease, stroke and diabetes.

Research from Purdue University in 2013 found that frequent consumption of artificial sweeteners, including aspartame, sucralose (Splenda®) and saccharin, was associated with weight gain, metabolic syndrome, diabetes and heart disease because of the “metabolic derangements” it seems to cause. (26)

The Northern Manhattan Study, focused on the study of stroke and pertinent risk factors, found a significant increased risk of heart events — even when controlling the study for those with various related diseases — in people who drink diet soft drinks each day. The same link was not discovered for those drinking regular soda. (27)

Like the carcinogenic risks of aspartame, the heart disease risks also seem to rise when individuals are exposed to it in the womb. People exposed prenatally to aspartame eat more sweet foods in adulthood, are obese, and more often have high blood sugar, high LDL cholesterol and high triglycerides. (28, 29)

4. May Cause Nervous System and Brain Disorders

Since many of the major complaints about aspartame are neurologic in nature, particular attention has been given to the way it affects the brain and neurological system.

Neurosurgeon Russell L. Blaylock, MD, released a book in 1998 called “Excitotoxins: The Taste That Kills,” detailing his research on aspartame and its relation to brain tumors, cell damage, and conditions like Alzheimer’s and Parkinson’s disease. He attributes these effects to the way the compounds in aspartame overstimulate neurons. (30)

Research at the University of North Dakota’s Department of Nursing found an increase in irritation, more depressive behavior and a decline in spatial orientation in people consuming a “high-aspartame diet.” These “high” aspartame levels were actually about half of what the maximum acceptable daily intake (ADI) values are, according to the FDA. (31)

This correlates with a 2014 animal study that found chronic aspartame consumption to be related to a distortion of neuronal function and an uptick in brain cell death in certain regions of the brain. This study was conducted using the FDI-approved ADI value. (32)

For those who also consume MSG (monosodium glutamate, another controversial food additive), these cognitive problems may be even more pronounced. MSG and aspartame exposure drastically drops dopamine and serotonin levels in the brain and cause oxidative stress that can damage brain cells. (33)

That’s not the only time it’s been found that aspartame induces oxidative stress and interrupts the body’s ability to fight it with antioxidants. This impact is most significant in cases of long-term aspartame consumption and is associated with memory loss and more in animal studies. (34, 35, 36)

One of the first studies on the subject of aspartame in the brain was conducted by John Olney, the founder of the field of neuroscience known as excitotoxicity, in 1970. He was a longtime opposer to aspartame’s legalization because of his extensive research on the subject.

His 1970 publication found that infant mice exposed to aspartame developed brain damage, even when given relatively low doses. (37) If this holds true in humans at some level, it could help explain why aspartame is linked to an increased risk of stroke and dementia (according to the Framingham Heart Study). (38)

There has also been at least one finding published in Neurology that aspartame intake exacerbated the number of EEG spike waves in children suffering absence seizures. (39)

5. Could Worsen or Trigger Mood Disorders

Closely related to its impact on neurological decline, aspartame may also be closely tied to the development of certain mental disorders, especially depression. Ingesting aspartame could potentially lead to a decline in learning and emotional function. (40)

Drinking diet beverages has been linked to depression more than once, including in one study of almost 264,000 participants over 10 years. Researchers found that those who drink more than four cans or cups of diet soda each day were between 30 percent and 38 percent more likely to develop depression, while coffee drinkers were 10 percent less likely to be diagnosed with depression. (41)

A famous study was conducted in 1993 to discover a correlation between mood disorders and aspartame in those with or without depression diagnoses. Before it could be completed, the Institutional Review Board had to halt the study because the participants who had a history of depression experienced such severe negative reactions that it led the department to discourage anyone with history of mood problems from ingesting aspartame because of their suggested high sensitivity to it. (42)

6. Possibly Contributes to Fibromyalgia

Over 6 million people in the U.S. suffer from the chronic pain disorder known as fibromyalgia. The causes and cure are still unknown, but one small study examined fibromyalgia patients who had been struggling for years to find effective treatments.

The study found that eliminating aspartame and MSG (two of the most common dietary excitotoxins) resulted in a complete or nearly complete resolution of all symptoms within a few months. The symptoms returned upon ingestion of either substance. (43)

This study was also submitted by Mark Gold of the Aspartame Toxicity Information Center to the FDA in 2003 without a positive response. (44)

7. Associated with Weight Gain

I introduced this piece by sharing a review of aspartame studies that found the non-nutritive sweetener was actually linked with weight gain rather than the weight loss it promises. (After all, drinks containing aspartame literally carry the label “diet.”)

I’ve also explained how drinking and eating aspartame products is associated with metabolic syndrome, one feature of which is excess belly fat. (45) So, I think we’ve established that aspartame does not help you lose weight. Now, the question is: Why?

There are a few suggested reasons aspartame does not lead to weight loss. For one, consuming non-nutritive sweeteners (sweet substances that do not have calories) does nothing for the sweet addiction they address. Instead, they actually trigger your brain to desire more sweet foods.

While eating sugar has that same effect, actual sugar has the benefit of providing caloric feedback, the “food reward” your body understands to mean it should stop eating. Aspartame, however, does the opposite — it encourages cravings and sweets dependence, all without the caloric feedback you need to control your intake. This, in turn, results in eating more non-nutritious foods and drinks. (46)

A 2014 experiment actually postulated that drinking diet beverages influences psychological processes that might cause a person to increase overall caloric intake. (47)

In addition to this interruption of normal biofeedback, a study published in late 2016 found that the phenylalanine in aspartame is an inhibitor of a digestive enzyme that protects against developing metabolic syndrome called “intestinal alkaline phosphatase.” (48)

So, not only do diet drinks lead to higher calorie consumption overall, but one of their compounds may actually stop your body’s normal responses that are meant to protect against obesity and other disease risk factors.

8. Might Cause Premature Menstruation

In a newer side of aspartame research, three U.S. universities studied young girls for 10 years to track growth and hormonal changes as well as lifestyle and diet. They found that drinking caffeinated soft drinks, particularly diet drinks, was associated with early development of menstrual cycles. (49)

Why does this matter? Because the long-term risks of early puberty include breast cancer, HPV, heart disease, diabetes and all-cause mortality. (50)

9. Linked to Development of Autism

By now, I hope you are convinced that aspartame is dangerous, particularly for pregnant mothers. One more reason to avoid this sweetener is because it has been linked to the development of autism in children.

In the journal Medical Hypotheses, researchers discussed a study in which women who had been exposed to dietary methanol (found in aspartame) were significantly more likely to give birth to children who developed autism. (51)

10. Increased Risk of Kidney Disease

In people with initially healthy kidney function, drinking diet sodas laden with aspartame may be associated with a 30 percent greater drop in kidney function than those who do not drink diet sodas. This research was conducted over 20 years and included over 3,000 women. (52)

11. Could Cause “Aspartame Disease”

This term, though not an officially recognized medical condition, was coined by a doctor named H.J. Roberts. He released an extensive set of research in his book, “Aspartame Disease,” in 2001 and advocated its ban by governing bodies until his death in 2013.

He considers this an epidemic in Western civilization that is ignored and actually sanctioned by the FDA and other governmental bodies. He claims the symptoms of aspartame disease include the following (not an exhaustive list):

  • Diabetes
  • Low blood sugar
  • Convulsions (seizures)
  • Headache
  • Depression and other mental disorders
  • Hyperthyroidism
  • High blood pressure
  • Arthritis
  • Multiple sclerosis
  • Alzheimer’s Disease
  • Lupus
  • Brain tumors
  • Carpal tunnel

Roberts and others, including Betty Martini of Mission Possible: World Health International (another anti-aspartame organization), encourage patients with these symptoms to consider that they may be suffering from aspartame disease and to abstain from it for a period of time before attempting any other treatment methods. (53)


Aspartame dangers - Dr. Axe


How Did This Get in Our Food, Anyway?

The Timeline of Aspartame’s Approval by the FDA

In December 1965, chemist Jim Schlatter at G.D. Searle stumbled upon aspartame while working on the formulation of new treatments for gastric ulcersAspartame, developed by G.D. Searle, was refused approval in 1973 due to inadequate evidence of its safety. Over the next 12 months, the FDA decided to approve it for use in dry foods, a decision overturned in subsequent months.

This decision was immediately opposed by attorney Jim Turner (a consumer advocate who had already been working to have dangerous artificial sweeteners removed from the market) and Dr. John Olney, a scientist who discovered in 1971 that aspartame caused brain damage in infant mice.

Turner and Olney’s petition gave the FDA reason to investigate G.D. Searle, who had submitted 113 studies on aspartame as part of the approval process. The then FDA commissioner, Dr. Alexander Schmidt, assigned an FDA task force to studies regarding aspartame.

Schmidt, after reviewing the task force’s findings of many manipulations, shortcuts and outright deception, stated on Congressional Record 1985a (page S5497) that, “[Searle’s studies were] incredibly sloppy science. What we discovered was reprehensible.”

In 1977, the FDA made a formal request for the U.S. Attorney’s office to investigate G.D. Searle on criminal charges, the first time in history it had ever made such a request. The grand jury began deliberations, and the law firm representing the accused began negotiating job terms with Samuel Skinner, the U.S. attorney in charge of this particular case.

Enter Donald Rumsfeld. Searle hired Rumsfeld as CEO in March of that year (who brought a few Washington cronies along). In July, Skinner left the U.S. Attorney’s office and began working for the law firm representing Searle.

The following month, FDA investigators released the Bressler Report, finding that over half of the animals in one of the Searle studies died in the midst of research without autopsies until much later, as well as multiple other discrepancies in the Searle research.

In December, the statute of limitations ran out on the grand jury investigation due to the stall by Skinner’s resignation.

A year and a half later, a Public Board of Inquiry (PBOI) was appointed by the FDA to investigate NutraSweet’s safety and potential risk. This board included three doctors and voted in 1980 to reject aspartame in additional products. The board members were still concerned about brain tumor risks.

January 1981 welcomed a sales meeting at Searle where Rumsfeld said this was the year to push for approval. Sources say he stated he would use political connections, rather than science, to make sure it happened before the end of ’81.

Ronald Reagan was sworn in as president later than month and included Rumsfeld on his transition team. Rumsfeld reportedly handpicked the new FDA commissioner, Dr. Arthur Hull Hayes Jr. After appointing a five-person panel to review the PBOI concerns, Hayes added a sixth scientist after realizing the panel was prepared to vote against aspartame’s approval. The decision ended up in a 3-3 tie, broken with a “yes” vote from Hayes in July 1981 to approve its use again for dry foods.

In October 1982, Searle filed for aspartame approval in carbonated beverages (and additional liquids). The National Soft Drink Association actually requested the petition be denied because of the breakdown of compounds in storage above 85 degrees Fahrenheit. Around the same time, Hayes resigned from the FDA after concerns about his acceptance of corporate gifts.

Amid the chaos, aspartame was officially approved for use in beverages, which were released beginning in fall 1983. (54) Additional safety concerns were raised in 1984, 1985 and 1986, but the FDA denied issues existed each time. NutraSweet was able to get aspartame approved for general bulk use in 1992.

Monsanto acquired G.D. Searle in 1985, earning Rumsfeld a $12 million bonus.

1995 marks the year that Thomas Wilcox, the FDA epidemiology branch chief, said the FDA would no longer accept adverse reaction reports or monitor the period research on aspartame. (55, 56)

Continuing Research

As I mentioned, industry-funded studies have, so far, discovered positive results about aspartame 100 percent of the time in their final reports (scientific skullduggery notwithstanding) while 92 percent of independently funded research finds potential dangers of aspartame. (57)

A 13-doctor panel petitioned the FDA, yet again, to re-examine the safety issues around aspartame, specifically the risk of tumors and various cancers (citing the Ramazzani study released in 2005, noted above). The request was denied. (58)

Aspartame received a bit of media attention again when the Podesta Emails were released on WikiLeaks, as Wendy Abrams, an environmental activist, forwarded information to John Podesta regarding the sketchy process by which NutraSweet was approved.

Better Alternative Sweeteners

Are all sweeteners bad? No, not all of them. There are a few I like, although one of my favorites is stevia. The rule for sweeteners is always in moderation. While these three can even provide health benefits, it’s best to limit your intake of sweets overall and tend more toward whole foods like vegetables, fruits and organic meat.


The stevia plant has been around for a millennia and a half in parts of South America and is about 200 times sweeter than sugar, gram for gram. There are several benefits to stevia, including some laboratory evidence that stevia kills lyme disease.

When using stevia, make sure to avoid dangerous altered stevia blends (which often contain very little stevia) and stick to pure, organic stevia.

Raw Honey

Raw, organic honey has been known to help counter the effects of certain allergies as well as help manage weight, promote sleep and fight oxidative stress.

Monk Fruit

This fruit-based sweetener has no calories but is between 300–400 times sweeter than sugar. There is evidence that it may help to lower risk of diabetes and cancer as well as combat infection.

Final Thoughts on Aspartame

  • Aspartame is a non-nutritive sweetener that has been around for a few decades and is found often in diet sodas, like Diet Coke or Diet Pepsi, as well as sugar-free and “no sugar added” food products.
  • Aspartame breaks down into two amino acids, phenylalanine and aspartic acid, as well as methanol (which converts to formaldehyde and diketopiperazine). The last three of this list are known carcinogens.
  • The methanol and formaldehyde are especially dangerous to humans because of the way they metabolize in the body, coupled with the fact that we do not have the necessary enzyme to convert formaldehyde to a less dangerous substance, as most animals.
  • Many studies have been conducted on aspartame dangers and found that it is linked with a large number of health conditions ranging from headaches to cancer to diabetes.
  • The “aspartame controversy” is not so much a controversy as it is a refusal to face the truth of what aspartame is and how it affects the body.
  • Drinking or eating aspartame products is especially dangerous for mothers and young children because of the way it affects behaviors and conditions later in life.
  • There are absolutely no benefits to consuming aspartame; in fact, the weight loss benefits it’s promoted for are totally false. Aspartame (and other non-nutritive sweeteners like erythritol) is associated with weight gain and higher BMI.
  • If you are experiencing conditions that could potentially be related to aspartame, it’s probably a good idea to abstain entirely and see if any symptoms alleviate on their own. This should be done under the supervision of a doctor.
  • Instead of drinking diet soda, regular soda or sugary fruit juices, satisfy your craving for a tasty drink by drinking kombucha and healthy tea.

Read Next: 7 Food Additives that Trigger Leaky Gut

From the sound of it, you might think leaky gut only affects the digestive system, but in reality it can affect more. Because Leaky Gut is so common, and such an enigma, I’m offering a free webinar on all things leaky gut. Click here to learn more about the webinar.

Josh Axe

Get FREE Access!

Dr. Josh Axe is on a mission to provide you and your family with the highest quality nutrition tips and healthy recipes in the world...Sign up to get VIP access to his eBooks and valuable weekly health tips for FREE!

Free eBook to boost
metabolism & healing

30 Gluten-Free Recipes
& detox juicing guide

Shopping Guide &
premium newsletter


Leave a Reply

Your email address will not be published. Required fields are marked *


  1. Annetts cook on

    Is aspertain made from E-coli feces? I stopped drinking diet cokes and using all diet sugar except Splinda almost 4 years ago. The last 2 months I have been using Stevia and Splinda. Trying to get completely off Splinda but I don’t really like the taste of Stevia. Will I have permanent damage. I did have fibromyalgia but have not have a flare up for 3 years.

    • Susan on

      I use Monk fruit extract because it tastes better than stevia. It is by In The Raw and comes in 4.8 oz bag. Zero calorie sweetener and natural.

  2. John E. Garst, PhD, Emeritus Professor (Medicinal Chemistry, Pharmacology, Toxicology, and Nutrition) on

    Aspartame is perfectly safe used as directed. Any real toxicologist knows that methanol is a degradation product of pectin (from apples and other fruits). However, food-borne concentrations of methanol present little harm. While it is true that this methanol is oxidized to formaldehyde, that formaldehyde is nearly all tightly bound to serum proteins(albumin) that it poses little risk. Moreover, the small amounts of unbound formaldehyde is rapidly (air) oxidized to formate. This formate is what the vitamins folic acid (folate) and B12 must have to complete their important vitamin function. That is, to reduce these important one carbon fragments back to methyl derivatives that regulate DNA (and prevent cancer) and much other vital biochemistry. Aspartame is but another way to obtain these vital one-carbon precursors.

    Your document is loaded with references, however, many, if not most of your citations have been completely rejected by real toxicologists as invalid. I would provide specific numbers, but it would take more space than this to list them. In short, such a post demonstrates not only that you are not a toxicologist, but that you are evidently unaware of the pertinent chemistry and biochemistry that dismisses all the arguments you put forth above. Remember, no relevant regulatory authority in the world has rejected aspartame safety and the EFSA just revalidated it several years ago. [And, by the way all the private studies on aspartame, including even all of the papers suggesting it is responsible for weight gain, have utilized inappropriate, invalid or irrelevant controls; they just don’t know why yet.]

    John E. Garst, PhD, Emeritus Professor (Medicinal Chemistry, Pharmacology, Toxicology, and Nutrition)

    • Jill on

      Thank you for this article. I am allergic to Aspartame, and it is getting harder and harder to find items that don’t have it as an ingredient. In fact these days when I do my shopping at the supermarket (in South Africa) my body even reacts when I walk past, for example, flavoured bottled water, or ‘sugar-free’ cookies, etc. I respond intuitively, but the closed I way I can describe the feeling I get is, it affects my breathing, but there is an instinctive reaction of an internal repelling. I’m sure others of your readers can relate…?
      Thanks again. I have been warning friends and colleagues of the dangers of Aspartame for several years already.

    • Caden Mitchell, RD on

      Caden Mitchell, RD (Outpatient Bariatric Dietitian, Lourdes Surgical Associates)

      Dr. Garst is spot on and has done a fantastic job explaining the break down of Aspartame in the body. There are no adverse effects to consuming safe amounts as defined by the FDA and the data above has been cherry picked. PLEASE DO NOT BELIEVE EVERYTHING YOU READ ONLINE (ESPECIALLY NOT FROM PEOPLE WHO MAY HAVE BIAS FROM GENERATING A PROFIT)! Chiropractors are not generally the best option to seek nutrition advise from. That does not mean all of their advise is bad, however, a registered dietitian or physician is more likely to be equipped with the correct information to answer your questions and concerns regarding nutrition.

    • Scott Ferguson on

      I appreciate your learned opinion, but the question of whose research or references are credible or not is moot to me. The impact of aspartame on my body is real, negative and repeatable. Shortly after ingestion, my body starts to shut down. Dizziness, headache and lethargy symptoms are significant. I suspect this follows a drop in blood pressure and heart rate, but I’ve not had the appropriate devices on hand to measure these properly.

      Your claim that “Aspartame is perfectly safe used as directed” does not apply to me. And growing empirical evidence suggests that I’m not the only human on the planet exhibiting these symptoms. I’m perfectly happy avoiding sweeteners myself, but it’s disappointing that so many responsible authorities and experts are denying the negative side effects and long term impact.

      I’d be happy to volunteer for testing with any credible and real toxicologist!

      • Carol on

        I too cannot tolerate aspartame – usually the first sign for me after consuming anything with it in is that my mouth starts watering immensely and the taste in my mouth is horrid, I get intense headaches and feel nauseous, this is the extreme case and usually happens if I’ve eaten something containing it- soda, juices etc are instant as soon as I have just one mouthful so am able to stop before reaching more adverse reactions. I am finding that more and more products are using this and now have to check every label before consuming. If I go out for a drink I have to ask ‘Are you using sugar free cordial ?’ and its annoying when I specifically ask for a normal coke only to be given a diet coke. I have come to hate the words ‘sugar free’ on products because that usually means its laced with sweeteners and therefore unsuitable for me and unfortunately most products are going that way with supermarkets concentrating on sugar fee tinned products, cordials and fizzy drinks and even those not labeled as such seem to contain sweeteners of some description. My body obviously doesn’t like this additive and has its ways of letting me know thankfully.

  3. Jim Sniegowski on

    I have a question. I aspartame is broken down by the body upon ingestion, then how come so much of it is excreted into the water supply? Its been reported that Lake Erie contains thousands of tons of aspatame. (Just one body of water used as an example). How can that be?
    I’ve heard that aspartame passes through the human body.

    • John E. Garst, PhD, Emeritus Professor (Medicinal Chemistry, Pharmacology, Toxicology, and Nutrition) on


      Aspartame is completely degraded to its constituents upon consumption in humans, so any report of it in lakes must be from direct disposal (things like pouring unused soft drinks down the drain, etc). And that method of disposition will be true of all sweeteners. However, sucralose is designed not to be absorbed, so is completely excreted, see . The other sweeteners lie between these extremes.

      John E. Garst, PhD, Emeritus Professor (Medicinal Chemistry, Pharmacology, Toxicology, and Nutrition)

  4. Denise on

    What about Yacon syrup? It has a glycemic index of 1. What are your thoughts on it?
    Thank you for sharing this. I avoid aspartame like the plague and this gives me information to help others.

  5. Sharie Bukowski on

    Good morning Dr. Axe!! Thank you for taking a stand in today’s society and making people aware of our food industry!! I was addicted to aspartame and I was well on my way to some serious health issues and the medical world had no answers. I am praising God for how He removed me from getting aspartame and I started healing!! I had no idea that all those products were making me sick!! I do have concerns for long lasting damage but for now doing well.

  6. Carin on

    I avoid aspartamine but I do supplement with phenylalanine, which is one of the three compounds found in aspartamine. I find that DL-phenylalanine actually makes my pain decrease, it improves my energy level, and decreases my appetite. I take it specifically because it can cross the blood brain barrier. Phenylalanine definitely does not, as the article suggests, cause me pain, headaches or depression. Is it just the other compounds in aspartamine that are bad, or is phenylalanine also allegedly harmful?

  7. Mec Goudron on

    I followed up on the actual article you cited which concluded that ” Further research is needed to fully characterize the long-term risks and benefits of nonnutritive sweetener”.

    This seems at odds with your somewhat alarmist views of aspartame. If you read the response to the article you’ll see the major point made that Randomised Controlled Trials are a superior research method than Cohort Studies. The RCT in the article you cited was rather non-committal about the effect of aspartame, so again I am surprised how you could come to the conclusion you did.

    I have no medical qualifications but a careful reading of the research article is all that’s needed – and thanks for sourcing your opinion and the transparency for doing that.

  8. Damien on

    Check out this amazing aspartame experiment done by a housewife in California:
    My Aspartame Experiment: Report from a Private Citizen

    “Author Victoria Inness-Brown did everything in her power to give us a fair and accurate study on the effects aspartame has on rats. Using scientific methods she created two groups of rats, one was the control group and the other was given a name brand artificial sweetener that contained aspartame for their drink. She carefully logged the symptoms that both groups exhibited during their life span as part of the experiment…”

  9. Alexander Sheffer on

    I am sorry to tell everyone but this article can not be trusted. Based on the first few paragraphs alone, I am able to see that this is a poorly made article trying desperately to convince people that aspartame is bad. Not only do you insult the other side when confronted with opposing evidence, but your sources just do not have anything to do with aspartame and wether or not it is good or bad. For example you insulted the other side and showed me what this article is really about when you said “Of course, a few smaller cohort studies did find weight loss to be a benefit — but, as is the norm for aspartame research, those were sponsored by industries benefiting from positive outcomes.” This a thing that I was taught to look for in determining the credibility of sites. Not only did you insult the other side, but as I said, your sources were severely inadequate. Your third source was about glutamate, not aspartame. Your fourth source had the same information as what you stated, but said information had nothing to do with the issue at hand. And your source sixth source was highly outdated, as it was published in 1984. Just from these items alone I have to say that this article’s only purpose is to influence the reader to believe the writers opinion, not an unbiased debate.

    • David Pilati on


      I do agree that the first few references are older and not necessarily really heavy hitting. Go to the 20’s and 30’s and you will see the rather clear and disturbing effects.

      Also, calling out financial conflicts is entirely appropriate and not “insulting”. There are several fields that have these huge trends but the food industry has been particularly aggressive here.

      All articles are meant to influence a reader and are not debates.

      As a physician, we all are waking up to the dangers of aspartame and other artificial sweeteners.

  10. Rachael on

    I did not know how dangerous this stuff was until my 16 month old started having seizures that I’m sure are linked to aspartame. All her tests were normal no reason for seizures. Drs nor neurologists would agree that it was the aspartame. We have not gave her any meds since we been home since yesterday. She has had no episodes. Has not had aspartame containing drinks since either. She just started drinking it last week and just seized for no reason on Tuesday. So this stuff is no good.

  11. Melissa on

    I would like to know the studies that this article was based on. So many references to “studies”, yet nothing annotated that I can see to vet the claims being made. Please provide your sources.

    • Me on

      That’s because this article doesn’t use any real studies. Like everything we eat aspartame is harmless in moderation unless you allergic to it.

  12. Me on

    Another fear endured article that leaves out the facts. Anything in high doses can be dangerous and potentially lethal but having occasional soda isn’t going to kill you.

  13. Cindy on

    I have been a diet mountain dew addict for many years. It has effected my health more than I knew. 3 weeks ago I was ready to die I couldn’t function anymore. I went to a herb doctor and was told the diet mountain dew were killing me. I quit cold Turkey. It was a nightmare. I had a unbearable headache was sick. After drinking 3 2 liters a day. I drink lots of water now . I can see better. My mind is clearer. I’m still weak but each day it gets better. I advise anybody to quit now because it will destroy your health before you know it. My opinion is it should be illegal because it is addicting and everywhere I went and everything I did I had a diet mountain dew.


More Posts