Is Aspartame Bad For You? Side Effects & Recommended Dose

Updated in July 2023

Aspartame is an artificial sweetener that is sweetens foods up to 200 times more than sugar. It contains just 4 calories in 1 gram. It is highly used in the food industry to sweeten foods like gum, soda and cookies. 

Aspartame is also available in pharmacies, supermarkets and natural health stores. It is often used by diabetics to drinks foods like teas, juice and coffee as a sugar substitute. This sweetener can also be consumed by those looking to lose weight, as it has a sweet taste with a low amount of calories. 

It is important to highlight that aspartame consumption can lead to side effects like headaches, vomiting, and dizziness. It can also increase your risk for cancer, like lymphoma, bladder cancer and leukemia. 

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Possible side effects

Although it is considered to be safe for consumption within the normal recommended doses, some studies show that aspartame is linked to a higher risk for certain health conditions, such as: 

  • Alzheimer’s or dementia: When heated to temperatures above 80ºC, aspartame releases methanol into the system. This is a compound that, in excess, can cause nervous system diseases, like Alzheimer’s or dementia. Therefore, aspartame should not be used to cook, in coffee or in hot teas, nor in any baked dishes.  
  • Some types of cancer: Some studies show that regular consumption of aspartame can increase the risk for the development of certain types of cancer, like bladder cancer, urethral cancer, leukemia and lymphoma. 
  • Dysbiosis: Aspartame impedes normal bacterial development, which can lead to dysbiosis. Dysbiosis is characterized by an imbalance of intestinal bacteria, with an increase in harmful bacteria and a decrease in beneficial bacteria. 
  • Increased free radicals in the body: Consuming aspartame, even within the recommended doses, can increase the production of free radicals in the body, which can lead to immune system dysfunction. This can cause a higher frequency of colds, early aging or cardiovascular diseases. 
  • Diabetes or obesity: Recent studies show that the sweet taste of aspartame on the tongue sends signals to the brain to release insulin. Excessive insulin production and release can cause diabetes and obesity. 

Aspartame contains a chemical compound called phenylalanine, and is therefore contraindicated for people with a history of phenylketonuria. This a genetic condition in which the consumption of foods with phenylalanine becomes toxic in the body, and can lead to symptoms like seizures, agitation, nausea, vomiting or skin wounds. 

Recommended dose

The maximum recommended daily dose of aspartame is 40 mg per kilo (or per 2.2 lb) of body weight per day. For a person weighing 50 kg, this equates to about 2 grams, or 2 and half sachets of sweetener per day. 

In children or pregnancy, the maximum dose of aspartame is 5 mg per kilo (or per 2.2 lb) of body weight per day. 

Where to find & how to avoid it 

Aspartame is present in liquid and powder sweeteners to be added to drinks like tea, coffee and juice. It is also added to certain food products, like chewing gum, diet sodas, juice boxes, powdered juice mixes, yogurts, diet cookies, diet jello, ready-made tea and some powdered coffees. 

Many food products with a “diet” or “light” label use some kind of sweetener to substitute sugar and improve the flavor of the product. This can lead to high consumption of sweeteners without fully knowing.

To avoid excessive consumption of aspartame, it is best to avoid buying foods that contain sweeteners and to avoid using sweeteners when preparing food. You can opt for natural sweeteners, like stevia, which can still sweeten foods 200 to 300 times more than regular sugar and also contains less calories.