By Dr. Mercola
More than 90 countries have given the artificial sweetener aspartame the green light to be used in thousands of food and beverage products.1
Two hundred times sweeter than sugar, aspartame allows food manufacturers to produce sweet foods they can market as "low calorie," "diet," or sugar-free," appealing to hundreds of millions of consumers looking to cut sugar from their diets.
No doubt about it, the less sugar you include in your diet, the better. But replacing sugar with aspartame is not the solution, and in fact is likely to be even worse for your health.
Despite assurances from the U.S. Food and Drug Administration (FDA) and other public health agencies that aspartame is safe, the research says otherwise…
So What the Heck is Aspartame Made Of?
Virtually all of the marketing material emphasizes the fact that aspartame is natural and made of two amino acids, the building blocks of protein. But, like many deceptions, this is only partially true. While there are two amino acids that comprise 90% of aspartame, aspartic acid and phenylalanine, they are held together in a methyl ester bond that comprises 10% of the molecule.
The methanol is released from the aspartame within hours of consumption after hydrolysis of the methyl group of the dipeptide by chymotrypsin in the small intestine. Once this methyl ester bond is broken it liberates free methyl alcohol or methanol, which is commonly called wood alcohol. The problem with methanol is that it passes into your blood-brain barrier and is converted into formaldehyde, which causes the damage. You may recognize formaldehyde as embalming fluid.
Interestingly, methanol is only toxic in humans. All other animals are able to detoxify it before it causes damage.
Methanol is a toxin that destroys the myelin tissue in your body, which is the insulating material around your nerves that allows nerve signals to travel properly. Once injured, one can have what are called demyelinating symptoms that are commonly seen in diseases like MS and also migraines that can include bizarre and inconsistent visual field disruptions.
My sister that helped me start my practice in 1985 is actually one of the people that develops these symptoms when exposed to aspartame. In the late '80s I helped to diagnose her with this sensitivity and she has avoided it for over 25 years.
Why is Methanol So Toxic?
Methanol breaks down into formic acid and formaldehyde in your body. Many experts believe formic acid is the problem but the real problem is the formaldehyde, which is a deadly neurotoxin and carcinogen. An EPA assessment of methanol states that methanol "is considered a cumulative poison due to the low rate of excretion once it is absorbed. In the body, methanol is oxidized to formaldehyde and formic acid; both of these metabolites are toxic."2
They recommend a limit of consumption of 7.8 mg/day. But according to Woodrow Monte, Ph.D, R.D., director of the Food Science and Nutrition Laboratory at Arizona State University:3
"When diet sodas and soft drinks, sweetened with aspartame, are used to replace fluid loss during exercise and physical exertion in hot climates, the intake of methanol can exceed 250 mg/day or 32 times the Environmental Protection Agency's recommended limit of consumption for this cumulative toxin."
Further, he states that due to the lack of a couple of key enzymes, humans are many times more sensitive to the toxic effects of methanol than animals. Therefore, tests of aspartame or methanol on animals do not accurately reflect the danger for humans.
"There are no human or mammalian studies to evaluate the possible mutagenic, teratogenic, or carcinogenic effects of chronic administration of methyl alcohol," he said.
Symptoms from methanol poisoning are many, and include headaches, ear buzzing, dizziness, nausea, gastrointestinal disturbances, weakness, vertigo, chills, memory lapses, numbness and shooting pains in the extremities, behavioral disturbances, and neuritis. The most well known problems from methanol poisoning are vision problems including misty vision, progressive contraction of visual fields, blurring of vision, obscuration of vision, retinal damage, and blindness. Formaldehyde is a known carcinogen that causes retinal damage, interferes with DNA replication and may cause birth defects. The researchers in the featured study then reasoned that the aspartame-induced methanol exposure was likely possible for oxidative stress in the brain.
New Study Shows Aspartame Damages Your Brain
A newly published study with rats investigated the chronic effect of aspartame on oxidative stress in the brain. Researchers found that there was a significant increase in lipid peroxidation levels, superoxide dismutase activity, GPx levels and CAT activity, showing that chronic exposure of aspartame resulted in detectable methanol in the blood, which may be responsible for the generation of oxidative stress and damage in the brain.4
So the study found that aspartame exposure did result in "detectable levels" of methanol in the blood. Methanol is gradually released in the small intestine when the methyl group of aspartame encounters the enzyme chymotrypsin.
Are Artificial Sweeteners Stressing Out Your Brain?
Oxidative stress can be defined as the state in which damaging free radicals outnumber your antioxidant defenses. Oxidative stress tends to lead to accelerated tissue and organ damage.
Case in point, earlier this year another study investigated the effect of long-term intake of aspartame on the antioxidant defense status in the rat brain and also found it leads to oxidative stress.5 Male rats that were given a high dose of the artificial sweetener exhibited a lowered concentration of reduced glutathione (the active, antioxidant form of glutathione), and reduced glutathione reductase activity, a sign of increased oxidative stress-induced damage in the body.
Glutathione deficiency has also been linked to age-related diseases such as Alzheimer's. Examination also revealed mild vascular congestion – an obstruction of the normal flow of blood within the brain – in these rats. Researchers concluded:
"The results of this experiment indicate that long-term consumption of aspartame leads to an imbalance in the antioxidant/pro-oxidant status in the brain, mainly through the mechanism involving the glutathione-dependent system."
Adding to the problem, one of the amino acids in aspartame, aspartic acid is capable of crossing your blood-brain barrier. There it attacks your brain cells, creating a form of cellular overstimulation called excitotoxicity, which can lead to cell death.
Your blood-brain barrier, which normally protects your brain from excess aspartate, as well as toxins, is not able to adequately protect you against the effects of aspartame consumption because it:
- Is not fully developed during childhood
- Does not fully protect all areas of the brain
- Is damaged by numerous chronic and acute conditions
- Allows seepage of excess aspartate into the brain even when intact
That excess aspartate slowly begins to destroy neurons, and the large majority (75 percent or more) of neural cells in a particular area of the brain are killed before any clinical symptoms of a chronic illness are noticed. Then, when they do occur, they may or may not be associated with aspartame consumption, even though examples of chronic illnesses that are made worse by long-term exposure to excitatory amino acid damage include:
Multiple sclerosis (MS) ALS Memory loss Hormonal problems Hearing loss Epilepsy Alzheimer's disease and dementia Parkinson's disease Hypoglycemia AIDS Brain lesions Neuroendocrine disorders
Why Was Aspartame Ever Approved?
If it causes brain damage, why is aspartame allowed in our food and drinks? The truth of the matter is the FDA rejected aspartame not once but multiple times. The scientific data just did not support it as a safe product. But the FDA is a federal agency subject to the political winds, and the people in charge of the agency have repeatedly and notoriously been accused of many conflicts of interest, both economically and ethically.
In 1975, the FDA came to the conclusion that aspartame should not be allowed on the market. They requested that further studies be conducted. The FDA's next move was to set up a public board of inquiry composed of outside experts to investigate the safety of aspartame, and in 1980 that board unanimously rejected aspartame's request for approval. Another internal FDA panel convened in 1980 also rejected aspartame for approval.
So it was three strikes against aspartame at this point, four strikes if you count the Bressler Report. This report was compiled in 1977 after FDA scientists looked into the field studies conducted on aspartame. The Bressler Report uncovered fraud and manipulation of data so serious that the FDA forwarded their files to the Chicago U.S. Attorney's office for prosecution.
Basically the results of the scientific data were fairly clear up until 1980: Aspartame was a dangerous, brain-tumor-causing man-made poison and the company trying to get it into the food supply was recommended for prosecution by the FDA. You would think that would be the end of aspartame, right?
Not by a long shot.
For more details on the story of how aspartame made it through the FDA approval process despite warning signs of potential health hazards and alleged scientific fraud, please watch the 60-Minutes report below, as Mike Wallace does a nice job of summarizing an otherwise very long story.
Did You Know Aspartame May Make You Fat?
If you're one of the people who suffers from headaches/migraines, vision problems, fatigue, anxiety attacks, abdominal pains or other symptoms when you consume aspartame, deciding to eliminate it from your diet was probably an easy choice.
For the rest of you, doing so based on the possibility that it could "one day" cause symptoms of brain damage is much more abstract, and probably much less likely to make you take action today.
That's why I want to share with you one of the major deceptions surrounding artificial sweeteners like aspartame, which is that they will help you lose weight by avoiding sugar.
This is a MYTH. Research has shown that artificial sweeteners can:
- Stimulate your appetite
- Increase carbohydrate cravings
- Stimulate fat storage and weight gain. In fact, diet sodas, which are well-known sources of artificial sweeteners, may actually double your risk of obesity!6
So much for being a dieter's best friend... The point is, if you're having a hard time giving up aspartame based on its potential to damage your brain, maybe the fact that it could make you pack on the pounds in the very near future will motivate you toward positive change.
My Favorite Tool for Addressing Artificial Sweetener Addictions
Artificial sweeteners tend to trigger enhanced activity within your brain's pleasure centers, yet at the same time provide less actual satisfaction. This separation of the taste of sweetness from caloric content means that when you consume artificial sweeteners, your brain actually craves more of it because your body receives no satisfaction on a cellular level by the sugar imposter. This can actually contribute to not only overeating and weight gain, but also an addiction to artificial sweeteners.
In order to break free, be sure you address the emotional component to your food cravings using a tool such as the Emotional Freedom Technique (EFT). More than any traditional or alternative method I have used or researched, EFT works to overcome food cravings and helps you reach dietary success. If diet soda is the culprit for you, be sure to check out Turbo Tapping, which is an extremely effective and simple tool to get rid of your soda addiction in a short amount of time.
If you're determined to sweeten your foods and beverages, I urge you to consider using stevia extract – a safe and natural sweet herb, which is my personal sweetener of choice. Lo Han is another herbal sweetener that doesn't have the aftertaste of stevia that many object to.