I suffered from chronic daily headaches for about 8 years. The headaches were never terrible nor debilitating, but always present. It was as if I was in a constant state of fogginess. During medical school, I drank about 1 liter of diet soda every day while I studied. In residency, I switched to Crystal Light Iced Tea because I decided I needed to cut down on my soda intake. During one particularly busy week in residency, I ran out of my iced tea and was unable to make it to the grocery store. I didn’t realize it at first, but over the course of the week my ever-present headaches disappeared. By the end of the week, I was noticeably better and my fogginess had lifted completed. I wasn’t sure the reason, but I was certainly thrilled. Fast-forward to the next week when I was able to get to the grocery store, and all of a sudden my headaches returned.

It took me a while to make the association, but I ultimately figured out that 8 years of suffering, in my case, was due to aspartame consumption. I now avoid it like the plague and have had a negligible number of headaches over the last 12 years. That’s not to say that I don’t get headaches here or there but many of them I can trace back to eating foods, sweets or drinks which I didn’t realize at the time, contained aspartame.

Aspartame is one of the artificial sweeteners found in many diet sodas but is also being utilized as a sweetener in many foods such as:

• Powdered drinks
• Flavoring syrups for coffee
• Sweetened iced teas
• Fruit and vegetable juices
• Flavored waters
• Gums
• Candies
• Yogurt
• Certain condiments and desserts
• Meal replacement bars

Why is this an issue?

Aspartame is broken down by enzymes in our body into phenylalanine, aspartic acid, diketopiperzine, and methanol. These breakdown products can have significant effects of on our bodily functions and metabolism.

According to a review article published in the European Journal of Clinical Nutrition in 2009, aspartame can:

• Disturb amino acid metabolism
• Disturb protein structure and metabolism
• Impair neuron functioning
• Cause endocrine imbalances
• Change the concentration of neurotransmitters in the brain
• Cause excessive nerve firing in the brain
• Compromise the function of the blood brain barrier
• Affect fertility

In certain individuals, a byproduct of aspartame breakdown, methanol, can cause a toxicity that mimics fibromyalgia. Symptoms can include spasms, shooting pains, numbness in legs, cramps, vertigo, dizziness, headaches, tinnitus, joint pain, depression, anxiety, slurred speech, blurry vision and memory loss.

It is very important to prevent toxic substances from entering into our brain where they can cause inflammation and damage neurons. This is the role of the blood brain barrier. This barrier has transporters that allow important amino acids to cross into our brains to be used to make needed substances called neurotransmitters. These neurotransmitters are chemicals that allow communication between brain cells to control everything from our moods, and emotions to our sleep-wake cycles.

Essentially, what happens is that when we eat and drink foods with aspartame our bodies digest the aspartame into its components. The high levels of these breakdown products (particularly phenylalanine) can flood or overload the transporters in the brain and allow too much phenylalanine to get into the brain and prevent other needed amino acids from entering. This can lead to too much of certain neurotransmitters being produced while inhibiting the formation of others. These imbalances may influence or worsen diseases such as Parkinson’s, Multiple Sclerosis, and Epilepsy.

In addition to the neurological effects described above, multiple studies have shown that daily consumption of diet soda results in an increased risk of metabolic syndrome (a group of symptoms such as abdominal obesity, elevated blood pressure, elevated fasting blood sugar levels which raise your risk for heart disease) as well as type II diabetes. Specifically, a study done collectively by Columbia University and the University of Miami, published in the Journal of General Internal Medicine in Sept 2012, followed diet soft drink consumption over 10 yearsand found that daily diet soft drink consumption led to an increase of vascular events such as stroke, heart attack or vascular disease. There was however, no increased risk seen with regular soda consumption or infrequent diet soda consumption.

Therefore, the take home message is that very infrequent diet soda and artificial sweetener consumption is probably okay unless you are like me and can’t tolerate even small amounts. If you suffer from chronic daily headaches, seizures, chronic fatigue, chronic pain, infertility, neurological diseases, or even autoimmune diseases, consumption of artificial sweeteners may be exacerbating your conditions. A trial of elimination of all artificial sweeteners may help to alleviate or even in some cases eliminate some of your symptoms.