Is your sugar-free sports drink doing you more harm than good? Are you trading sugar for something much more dangerous? All artificial sweeteners are hiding the bitter truth about their health effects, but beware of this one particularly: aspartame.


What is aspartame?

Aspartame (L-aspartyl-L-phenylalanyl-methyl ester) is an artificial sweetener used as a sugar substitute. Aspartame consists of aspartic acid, phenylalanine, and methanol; all of these three can harm our body in the ways that will be discussed later in this text. Aspartame was accidentally discovered in 1965 during an anti-ulcer drug development in  G.D. Searle pharmaceutical company. FDA approved the use of aspartame in carbonated beverages in 1983, although some health authorities warned about its potential dangers and stopped the initial approval in 1974. Aspartame is about 200 times sweeter than sucrose and has negligible caloric value, which makes it an attractive sugar substitute.

Aspartame in sports drinks

Aspartame is widely used in the beverage industry. As people are becoming increasingly aware of sugar’s potential negative effects on health and weight, aspartame and other non-caloric sweeteners are gradually taking its place in various drinks. Since athletes care about weight control and calorie intake, aspartame became a ubiquitous ingredient in sports drinks. Brands that decided to steer clear of aspartame, like Flow Drinks, are now a minority. It can be tricky to recognize aspartame on nutritive labels. Brand names “NutraSweet”, “Equal” and “Sugar Tween” also hide this controversial sweetener. One recent try to mask aspartame on nutritive labels and make it sound more natural is the brand name “AminoSweet”. However you call it, aspartame is lurking in the majority of sports drinks on the market, so beware when choosing one for yourself. Fortunately, natural alternatives are now available.

Is aspartame safe?

In the United States, the acceptable daily intake of aspartame is 50mg/kg (1). In Europe, this value is slightly lower -40mg/kg- but European Food Safety Authority (EFSA) also considers aspartame safe for human consumption (2). However, it is worth reminding that aspartame is approved under suspicious circumstances, despite the initial objections of concerned health authorities. Furthermore, it is made of three potentially toxic ingredients and numerous side effects of aspartame have already been reported and scientifically confirmed. With all this in mind, aspartame safety remains questionable. Many reputable health experts have written entire books on aspartame dangers in an effort to raise public awareness about this food additive.

Aspartame side effects

Although the Food and Drug Administration (FDA) claims that aspartame is safe, it accounts for staggering 80% of all reported side effects to food and additives (FDA Consumer, October 1988). Aspartame side effects range from headaches, nausea, and fatigue to memory loss, seizures, and severe depression. According to these reports, aspartame can also trigger or worsen chronic diseases like brain tumors, fibromyalgia and Alzheimer’s disease (3). Apparently, both European and American regulatory authorities are still ignoring serious side effects of aspartame and suggest it as a great sugar substitute.

Aspartame is comprised of two amino acids: aspartic acid and phenylalanine. They can both cause us harm when present in their free state -not bound to proteins. The aspartic acid salt, aspartate, acts as a neurotransmitter in the brain. In excessive amounts, it can damage and even kill brain cells by overstimulating them. Glutamate, part of another food additive called monosodium glutamate (MSG) has a similar effect and these substances are called excitotoxins (4). That’s why the combination of aspartame and MSG can be especially harmful and why you should opt for brands like Flow Drinks, avoiding the artificial additives altogether. Phenylalanine can also harm the brain in its free form, especially for people who can’t metabolize it due to the genetic disorder called phenylketonuria (PKU). Aspartame can significantly increase the blood levels of phenylalanine, even in people without PKU. This can deplete brain serotonin supplies and contribute to various emotional disorders, like depression (5).

Aspartame and cancer

Aspartame can release methanol in the small intestine, or even before consumption if exposed to high temperatures (above 30oC). Our body metabolizes methanol into formaldehyde, a known carcinogen and neurotoxin. Symptoms of methanol poisoning can be extremely serious, even lethal. They include vision problems, nausea, and neurological damage. Studies have confirmed that methanol from aspartame causes immune dysfunctions, cell damage and cancer (6,7).

Aspartame vs sugar

Many athletes, especially diabetics, avoid sugar and they often choose sports drinks labeled as “sugar-free”, which contain aspartame and other artificial sweeteners. Sugar has a lot of calories -yet poor nutritional value- so athletes use sugar substitutes like aspartame in order to control their weight and calorie intake. Sugar remains the enemy of our health, but it is actually a much safer option than aspartame. People drink diet sodas and sweeten their food with aspartame and other sugar substitutes for the sake of their health and looks; this practice turned out to be fundamentally wrong. In addition to the myriad of negative health effects, a recent meta-analysis showed that aspartame doesn’t help in weight control. It can even increase the risk of metabolic and cardiovascular diseases (8). And after all, if you are engaged in an intense physical activity, those calories in your sports drink can keep you energized. A balanced low-carb natural formulation, like the one in Flow Drinks, will ensure optimal calorie intake and keep your weight under control.

Aspartame healthy alternatives

If you are avoiding sugar, there are some healthier options. Instead of reaching for sugar-free products that contain aspartame, you can use natural sweeteners like honey, malt extract and agave syrup. Just make sure you consume them moderately, given their high caloric value. When it comes to sports drinks, make sure you choose brands that don’t use aspartame and other artificial sweeteners. That being said, sports drinks loaded with sugar aren’t the best alternative. Flow Drinks have a unique natural formulation and low carbohydrate content. They maintain optimal blood glucose levels during the physical activity, keeping the body fresh and energized.



  1. gov. (2017). Additional Information about High-Intensity Sweeteners Permitted for use in Food in the United States. [online] Available at:
  2. (2017). Scientific Opinion on the re-evaluation of aspartame (E 951) as a food additive | European Food Safety Authority. [online] Available at:
  3. gov. (2017). Reported Aspartame Toxicity Reactions. [online] Available at:
  4. Gillessen, T., Budd, S. and Lipton, S. (2017). Excitatory Amino Acid Neurotoxicity. [online] Available at:
  5. Walton RG, e. (2017). Adverse reactions to aspartame: double-blind challenge in patients from a vulnerable population. – PubMed – NCBI. [online] Available at:
  6. Choudhary R, e. (2017). Longer period of oral administration of aspartame on cytokine response in Wistar albino rats. – PubMed – NCBI. [online] Available at:
  7. Soffritti M, e. (2017). The carcinogenic effects of aspartame: The urgent need for regulatory re-evaluation. – PubMed – NCBI. [online] Available at:
  8. Azad, M., e. (2017). Nonnutritive sweeteners and cardiometabolic health: a systematic review and meta-analysis of randomized controlled trials and prospective cohort studies. Canadian Medical Association Journal, 189(28), pp.E929-E939.

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