Few food additives have been studied with as much attention as aspartame.
Proponents of diet drinks claim that no adverse effects have been proven and that products containing aspartame contribute to weight loss. On the other hand, a large community of health-conscious practitioners and consumers is convinced that the responsible authorities for public health have turned a blind eye to one of the most dangerous food additives ever discovered.
The sweetener industry took a hit when a major study released in July 2017 linked aspartame to an increased risk of heart disease and a higher body mass index. Unlike smaller studies that are sometimes dismissed, this review included a total of nearly 407,000 people with a median follow-up of 10 years.
Researchers found that there are not only zero benefits from consuming diet foods and drinks containing these artificial sweeteners (known as non-nutritive sweeteners because they provide no calories), but they were also associated with weight gain, increased waist circumference, and a higher incidence of obesity, hypertension, metabolic syndrome, type 2 diabetes, and cardiovascular diseases.
What is aspartame?
To understand why aspartame causes adverse reactions, it is important to first explain what it is and how it metabolizes when you drink or eat it.
Aspartame is an artificial sweetener, also known as Acesulfame potassium (K), AminoSweet, Neotame, Equal, NutraSweet, Blue Zero Calorie Sweetener Packets, Advantame, NutraSweet New Pink, Canderel, Pal Sweet Diet, and AminoSweet. It is used in a variety of food and wellness products, such as diet soda, gum, candies, and vitamins.
Almost immediately after consuming aspartame, it breaks down into three chemical compounds: phenylalanine, aspartic acid, and methanol.
The first two components are amino acids. Methanol is known as wood alcohol and is toxic in large doses, but the amount of methanol in a serving of diet soda is approximately the same as that which occurs naturally, say, in a glass of grape juice. Sounds safe, right? After all, we need amino acids to survive, and methanol can’t be that bad if it’s also in grape juice, right? Unfortunately, these arguments, widely used by companies profiting from the sale of aspartame, do not hold up. Methanol has no health benefits and is particularly dangerous when consumed through aspartame.
Phenylalanine is an amino acid that can be toxic in large doses, but it is generally recognized as safe in whole food products. However, when chemically bound to other compounds, such as in aspartame, phenylalanine is absorbed almost immediately into the bloodstream, rather than slowly through digestion.
Because this amino acid can cross the blood-brain barrier and acts as an excitotoxin when absorbed too quickly, it can interfere with various neural processes. Just one diet soda raises the level of phenylalanine in the brain, leading to a decrease in serotonin levels. In at least one study, phenylalanine concentrations were higher in individuals with HIV, sepsis, cancer, and those suffering from trauma.
How safe is it? Does it cause cancer?
There is some concern about how the body metabolizes the two amino acids in aspartame. Because of the way aspartame products are created, the amino acids they contain do not go through the normal breakdown and enzyme release process. Instead, they are absorbed 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 binds to pectin, a fiber commonly found in fruits. Generally, these pectin/methanol bound compounds are safely excreted through the normal digestive process.
In aspartame, however, methanol binds to the phenylalanine molecule. One or two processes break that bond and create what is known as free methanol. In cases where the aspartame product has been stored in a hot environment (such as a warehouse or truck), the bonds break down before ever entering the body.
Free methanol then converts to formaldehyde, more commonly known as embalming fluid. Both methanol and formaldehyde are carcinogenic in themselves. Formaldehyde has the unfortunate ability to cross the blood-brain barrier, which is why it is so damaging to the body. Ultimately, formaldehyde can also convert to diketopiperazine, another known carcinogen.
Products Containing Aspartame
Aspartame is found in over 6,000 individual products, making it practically impossible to list them all here. However, I hope understanding the impact of nutrition on your health makes you a passionate label reader. If you are considering purchasing any of the following types of items, check the label—you will likely find aspartame on the list.
The following foods, drinks, and medications typically contain aspartame:
Diet soda (sugar-free added)
Sugar-free candies
Sugar-free cereals (or sugar-free added)
Sugar-free condiments (or sugar-free added)
Flavored syrups
Flavored water
Sugar-free toppings and/or sauces
Diet tea products
Fruit juices with low sugar content or sugar-free
Meal replacement shakes/snacks
Nutritional bars
Sports drinks (especially those sugar-free)
Soft candies
Fruit yogurt (sugar-free, fat-free, and some brands of drinks)
Vegetable juice drinks
Natural fiber laxatives
Oral fiber supplements
Appetite control supplements
The Most Serious Dangers of Aspartame
1. Potentially Increases Cancer Risk
For decades, studies have shown the potential carcinogenic qualities of aspartame. An animal study showed a correlation between aspartame and various types of cancer, to the extent that the organization referred to it as a multi-potential carcinogen, even at doses well below the acceptable legal limits.
One reason this 20-year study is so significant is that 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 animals’ lifespan, often unexamined, as cancer most commonly occurs in humans during this portion of life. Overall, studies have found links between aspartame and the following:
Liver cancer in rats
Lung cancer
Brain cancer
Breast cancer
Prostate cancer
Cancers of the central nervous system (gliomas, medulloblastomas, and meningiomas)
The discovery of central nervous system cancers seems to be associated with the behaviors of the two amino acids found in aspartame. They are consumed in such large quantities and are not broken down in the same way as when ingested in other foods and have the ability to cross the blood-brain barrier.
The incidence of cancer appears to increase when animals are exposed to aspartame in utero, highlighting the importance of pregnant mothers avoiding aspartame altogether. And formaldehyde—a metabolite of free methanol—is associated with the development of cancers of the breast, stomach, intestines, lymphoma, and leukemia.
2. May Induce or Worsen Diabetes
Although doctors often recommend replacing sweet drinks with diet versions for diabetics, aspartame seems to have the opposite effect than hoped. Consumption of diet sodas is associated with a higher risk of type 2 diabetes, as well as metabolic syndrome, a group of symptoms indicating heart disease.
In a study of over 6,800 individuals of various ethnicities aged 45 to 84, the risk of diabetes was 67% higher for those who consumed diet soda sweetened with aspartame daily compared to those who did not consume it. In many cases, aspartame intake may also worsen diabetes symptoms, such as diabetic retinopathy and diabetic neuropathy.
Research shows that aspartame conflicts with insulin/glucose tolerance, a marker of prediabetes, especially for those who are already obese. One reason this may happen is due to how aspartame alters gut microbiota (healthy bacteria). These changes can induce glucose intolerance in otherwise healthy individuals.
3. Could Increase the Risk of Heart Disease and Stroke
Aspartame intake is associated with metabolic syndrome. This group of conditions includes high blood pressure, elevated blood sugar, excess abdominal fat, and high cholesterol/triglyceride levels. This marks a dramatic increase in the risk of heart disease, stroke, and diabetes. Research from Purdue University found that frequent consumption of artificial sweeteners, including aspartame, sucralose (Splenda), and saccharin, was associated with weight gain, metabolic syndrome, diabetes, and heart disease due to the metabolic disturbances they seem to cause.
4. May Cause Nervous System and Brain Disorders
Since many of the major complaints about aspartame are neurological in nature, special attention has been paid to how it affects the brain and the nervous system. Neurosurgeon Russell L. Blaylock published a book in 1998 titled “Excitotoxins: The Taste That Kills,” detailing his research on aspartame and its relationship to brain tumors, cell damage, and conditions such as Alzheimer’s and Parkinson’s disease. He attributes these effects to the way compounds in aspartame overstimulate neurons.
Research from the Nursing Department at the University of North Dakota found an increase in irritability, more depressive behavior, and a decrease in spatial orientation in individuals consuming a diet high in aspartame. These elevated levels of aspartame were actually about half of the maximum acceptable daily values according to the FDA.
5. Could Worsen or Trigger Mood Disorders
Closely related to the impact on neurological decline, aspartame may also be closely linked to the development of certain mental disorders, particularly depression. Ingesting aspartame could lead to a decrease in mood and emotional function. Consumption of diet drinks has been linked to depression multiple times, including in a study of nearly 264,000 participants over 10 years. Researchers found that those who drank more than four cans or bottles of diet soda each day had a 30% to 38% higher risk of developing depression, while coffee drinkers were 10% less likely to be diagnosed with depression.
6. May Contribute to Fibromyalgia
Over 6 million people in the U.S. suffer from chronic pain known as fibromyalgia. The causes and cures are still unknown, but a small study examined patients with fibromyalgia who had struggled for years to find effective treatments.
The study found that eliminating aspartame and MSG (two of the most common food excitotoxins) led to a complete or nearly complete resolution of all symptoms within a few months. Symptoms returned upon ingesting any of the substances.
7. Associated with Weight Gain
Studies on aspartame have found that the non-nutritive sweetener is actually linked to weight gain rather than the weight loss it promises. (After all, drinks containing aspartame literally carry the diet label.) Drinking and consuming products with aspartame is associated with metabolic syndrome in some individuals. It is quite clear that aspartame does not help you lose weight.
8. May Cause Early Menstruation
In a newer area of research on aspartame, three universities in the U.S. studied young girls over 10 years to track growth and hormonal changes, as well as lifestyle and diet. They found that consumption of caffeinated soft drinks, particularly diet drinks, was associated with the early onset of menstrual cycles.
Why does this matter? Because the long-term risks of early puberty include breast cancer, HPV, heart disease, and diabetes.
9. Linked to Autism Development
Another reason to avoid this sweetener is that it has been linked to the development of autism in children. In the journal Medical Hypotheses, researchers discussed a study in which women exposed to dietary methanol (found in aspartame) had much higher risks of giving birth to children who developed autism.
10. Increased Risk of Kidney Disease
In individuals with initially healthy kidney function, consumption of diet sodas loaded with aspartame may be associated with a 30% greater decline in kidney function than those who do not drink diet sodas. This research was conducted over 20 years and included over 3,000 women.
