Aspartame: The Good, The Bad and The Ugly

Aspartame, a non-nutritive sweetener (NNS), discovered in the 1980s, has had a profound impact on the weight loss industry and, conversely, has faced significant controversy. Over the last four decades, this compound has been one of the most exhaustively studied artificial sweeteners, and arguments, both for and against can be found. There have been periods where it has been touted as the cure for obesity and the panacea for diabetes, but this has been countered by dark periods where it has received blame for causing a wide range of diseases from mental health disorders to obesity and cancer.  

What is Aspartame? 

Aspartame is one of the most widely used artificial sweeteners available on the market and is commercially available under brand names such as Nutra Sweet and Equal. It is the compound responsible for the sweet taste of diet or sugar-free foods and beverages. What makes it so popular is its remarkable sweetness potency; while a gram of Aspartame contains 4 calories, which is the same as 1 gram of sugar, however, its sweetness is almost 200 times more intense. This means that the calories needed to achieve the same level of sweetness are negligible in comparison. 

Aspartame may be found in products such as  

• Diet Soda 
• Low calorie juice 
• Sugar-free gum 
• Low calorie desserts and candy 
• Sugar-free ice cream 

• Low calories flavoured yoghurt 

Apartame comprises two amino acids- Aspartic acid, which is a naturally occurring amino acid and Phenylalanine, an essential amino acid (which the body cannot synthesize). The primary source of concern regarding the adverse effects of Aspartame lies in its metabolic breakdown within the body. Once ingested, it is processed in the body to produce Methanol, which is toxic in large quantities, but not particularly harmful in the amounts produced in this case. However, Methanol is further degraded to produce Formaldehyde, which is considered both neurotoxic and carcinogenic. 

Aspartame as a Sugar Substitute 

The role of Aspartame as a calorie free substitute for sugar cannot be under-estimated. It provides sweetness without adding significant calories to foods and beverages, which makes it ideal for diabetic patients as it does not cause spikes in blood sugar and limits overall sugar consumption. By providing sweetness without the associated calories, Aspartame can help people reduce their overall calorie intake, which may support weight management efforts.  

Does Aspartame Cause Cancer? 

The biggest fear associated with Aspartame relates to its potential connection to certain cancers such as bladder and brain cancer. Early animal studies conducted in the 1970s and 1980s, showed a possible association between Aspartame and cancer in doses which were typically a hundred to a thousand times higher than usual human consumption. Subsequent research and more robust investigations, both in animals and humans did not show any conclusive evidence of a link between Aspartame consumption and cancer. 

After extensive review, the International Agency for Research on Cancer (IARC) and World Health Organisation (WHO) have downgraded Aspartame to a class 2B carcinogen. What this means is that although we have seen an increase in cancer risk in patients consuming Aspartame by almost 15%, research has not been able to definitively establish that Aspartame directly causes cancer. This is a complicated concept to prove or disprove.  

Basically, what scientists are trying to determine whether Aspartame in a diet is a direct cause of cancer or if other factors in an individual's diet or environment, such as red meat consumption, vitamin deficiencies, or tobacco use, could also potentially contribute to the risk of cancer. Could those other factors be the root cause of cancer and Aspartame just an innocent bystander? 

What is the Acceptable Daily Intake (ADI) of Aspartame? 

Health agencies and regulatory bodies from around the globe have come together and published guidelines for the safe consumption of Aspartame. This is the amount of Aspartame that can be consumed daily without an appreciable increase in risk of cancer and other side effects. The U.S Food and Drug (FDA) has set the ADI for Aspartame at 50 mg/kg of body weight. To put it in perspective, a can of diet soda contains 200 mg of Aspartame, which means that a 70 kg adult can safely consume 17 cans of soda. The European Food Safety Authority (EFSA) is more stringent and has established its limits at 40 mg/kg of body weight. This is not to say that you should aim to reach that limit every day, but it also means that you can safely reach for that can of diet soda without the guilt. 

Is there an Association Between Aspartame and Obesity? 

The relationship between Aspartame and obesity is complex and the evidence does not provide a conclusive association. On the surface, Aspartame is a low-calorie sweetener, widely used as a sugar substitute in many diet and low-calorie food products, contributing to reduced overall calorie intake and aiding in weight loss while potentially preventing obesity. However, some studies have indicated that ingesting Aspartame may trigger the release of "feel-good" hormones, such as Dopamine, potentially leading to a craving for sweet foods and an overall increase in food consumption. The take home from this is that while it is reasonable to use Aspartame in some of your foods, you need to be mindful of the dangers of developing an addiction to desserts.  

What are Other Side Effects of Aspartame? 

Over the years, Aspartame has faced much controversy; its opponents claim it is associated with significant adverse effects. Some of the side effects associated with Aspartame are listed below. 

• Stomach disorders- bloating, diarrhea, nausea 

• Mood disorders- depression 
• Skin problems 
• Attention Deficit Hyperactivity Disorder (ADHD) 
• Neurological deficits- dizziness, headaches, Alzheimer's 
• Allergies 

• Heart Disease/ Stroke 
• Cognitive effects 

It should be noted that although studies have shown an association between Aspartame and potential side effects, none of them have shown a causal relationship. Given the lack of consistency in scientific literature and the relatively small number of high-quality studies conducted on these health conditions, a lot more research is needed to establish a scientifically robust connection between Aspartame and any of the reported negative outcomes. 

Natural Alternatives to Aspartame 

If you prefer to avoid products containing Aspartame, there are natural non-nutritive sweetener (NNS) alternatives available. You might consider looking for products or sweetening your foods and beverages with options such as: 

• Monk fruit 
• Allulose 
• Stevia 
• Sugar alcohols 

While these alternatives are considered more "natural" as compared to Aspartame, it's important to use them in moderation and follow the recommended usage guidelines. 

References  

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1. Hodge AM, Bassett JK, Milne RL, English DR, Giles GG. Consumption of sugar-sweetened and artificially sweetened soft drinks and risk of obesity-related cancers. Public Health Nutrition 2018; 21(9):1618–1626. 

1. Pearlman M, Obert J, Casey L. The association between artificial sweeteners and obesity. Current Gastroenterology Reports 2017; 19(12):64.