Aspartame, the Sweet Evil?

Key Points

  • Aspartame is safe for consumption and is a good substitute for white sugar because of the very few calories present in it and aspartame doesn’t affect appetite and glucose or insulin levels.
  • Aspartame rapidly gets hydrolysed in the gut. Even when high doses of aspartame are consumed, the traces cannot be found in the blood due to rapid breakdown. Upon ingestion, aspartame breaks down into residual components, including aspartic acid, phenylalanine, methanol, and further breakdown products including formaldehyde and formic acid.
  • Aspartame when consumed in the “safe” limits, does not have any harmful effects on the human body. According to WHO, the ADI is 40-50 mg/kg.

With the internet being the battleground for debates, one of the most favourite topics of dieticians and nutritionists across the world is the safety of artificial sweeteners, primarily aspartame. With the wide range of options available for artificial sweeteners in the market, the nutritional benefits and the effect it has on health are debatable. Now and then, the media brings up how these artificial sweeteners are related to cancer, diabetes, blood sugar, gut health, or other chronic illness.

Artificial sweetener is a generic term for non-nutritive or non-caloric sweeteners. With the population transcending towards healthier food options, the masses are inculcating artificial sweeteners in their diet to reduce their sugar intake and lose weight. [2]

Aspartame is a zero-calorie alternative with a similar taste to sugar, it is 100-200 times more times sweeter than sugar. Due to this property of aspartame, even though it produces 4Kcal of energy per gram when mobilized, the quantity of aspartame needed to produce a sweet taste is very less which makes the calorie consumption negligible. [1] Unlike stevia, aspartame does not have a bitter aftertaste. It is because aspartame is a combination of two amino acids: aspartic acid and phenylalanine.[1] When someone replaces a high-calorie food or beverage with a zero-calorie alternative, the body does not only save on calories, more calories can be obtained from other nutritious sources. [3] For instance, if you switch your sugared milkshake with a non-sugared milkshake, your body is getting fewer calories. So, your body can take in more calories from other nutritiously dense sources.

Aspartame does not affect appetite, glucose, or insulin levels and easily save on a lot of calories in your diet and result in relatively easy weight loss. Who said there isn’t a thing like free lunches?

Aspartame is a heavily criticized sugar substitute, but due to its properties, it is available in more than 6,000 products in a supermarket. Aspartame is highly stable when added to cold things, which is why it has a high shelf life. Like many other peptides, aspartame may hydrolyse at an elevated pH or temperature.

To understand the effect of aspartame on healthy cells, a study was conducted on rodents. A certain type of cancer was increased in rodents, leukemia, and lymphoma, while the intake was lower than the ADI. Because of these findings, aspartame was treated as a potential carcinogen. [3][4] The DNA of a human and rodent are similar, most of the scientists believe that they both have completely different metabolisms. Hence, comparing the metabolic function of rodents and humans is unfair. In 2006, all the existing data were analysed and the research was carried forward. Later FDA confirmed their stance that aspartame “based on more than 100 toxicological and clinical studies regarding the safety of the sweetener” is safe for human consumption. It was even confirmed that aspartame is not a carcinogen. [3]

This brings us to the question, is Aspartame in our Diet Coke Safe? As we mentioned earlier, aspartame is 200 times sweeter than sugar. That’s why you need 200 times less aspartame to provide the same amount of sweetness, leading to a consumption of 200 times lesser calories. [3] Aspartame is basically calorie-free. Along with helping lose weight, aspartame doesn’t affect appetite and glucose or insulin levels.

Aspartame tends to break down when heated, due to the presence of phenylalanine, an amino acid. So, aspartame cannot be used while baking or cooking, as it will lose its sweetness.

Safe for consumption

Aspartame is an artificial compound, which makes people believe that it is not safe for consumption. It’s intriguing to know what exactly happens to aspartame when it enters your body, with respect to the metabolic reactions. The human body digests aspartame efficiently and fully. It does not accumulate in the body and gets broken down into 50% phenylalanine, 40% aspartic acid, and 10% methanol. The by-products of aspartame are a part of our daily food consumption; hence they are completely safe. [1][8]

So, how can aspartame be toxic? The toxicity of every compound depends on a person’s health issues, their consumption patterns, and dietary needs. In the case of aspartame, the ADI is 40-50 mg/kg according to the WHO. A woman weighing 50kgs can consume 16 cans of Diet Coke every day to fall ill because of aspartame toxicity. Unsurprisingly then, most people do not consume anywhere near the ADI. [6][7]

Glucose Tolerance & Gut Microbe

recent study in put light on the issue that artificial sweeteners might impair glucose tolerance or harm the gut microbiome.

In this study, a bunch of researchers at Weizmann Institute, Israel conducted an 11-week trial in which they fed mice three types of water. Each water sample contained 10% of the solution of different artificial sweeteners—aspartame, saccharin, and one with sucralose. After 11 weeks, all the mice displayed higher fasting glucose levels than mice who had been drinking normal water or water with a 10% glucose solution. [5]

Researchers even wanted to study the effect of artificial sweeteners on the gut. The gut microbiome of the mice was depleted via antibiotics to study its effect on glucose intolerance. When the gut microbiome was depleted, glucose intolerance had completely disappeared. If the bacteria-depleted mice were transplanted with bacteria from a rodent who had been ingesting saccharin, the glucose intolerance returned.

It was analysed that most artificial sweeteners aren’t digested through the normal GI tract. Instead, they travel to the intestine, where they can encounter and influence the makeup of the gut bacteria. [5]

Later these studies were replicated on humans. In the research group, seven people who didn’t consume sweeteners normally got the highest safe dose of saccharin possible for seven days. Four of the subjects had markedly worse glucose tolerance by day five. These four subjects also had different gut bacteria to start with and ended up with drastically different gut bacteria. Studies with sucralose and aspartame also concluded that they lead to depletion of the gut microflora as well.

Artificial sweeteners can be consumed in the “safe” limits. Consumption of a high level of artificial sweeteners daily is done by a very small audience. The most crucial take from the analysis id that most of these studies were performed on rats, which have a different metabolic process from humans. [5]

Can you be Aspartame Sensitive? 

Even after a large number of research papers written about the effects of aspartame on human health, the majority of them conclude that it has no harmful effects if consumed within the ADI. But some people have stated otherwise. Some people have complained of getting headaches or nauseous after consuming beverages with aspartame. [1]

To understand the science behind the adverse effect of aspartame on some people. A group study was done, in where people were given two drinks, one having aspartame as the sweetener and one with regular sugar. The group was told that both of them contained aspartame. The group reacted adversely to both the samples and there was no difference observed in the blood cultures too. Hence, the adverse effect of aspartame that was being reported was a placebo. [4]

So, how can a thing that gives us the sweetness that we want come without any health hazards. Right? Aspartame is definitely a great sugar substitute. The way our mind works accounts for the negative thoughts we have for aspartame. Anything that can help us with our diet without compromising on taste must not be good. But aspartame is here is satisfy our sweet tooth minus the calories. What more could you ask for?


  1. What 7 Studies Say About Artificial Sweeteners and Weight Loss – Legion Athletics. Legion Athletics. (2020). Retrieved 28 September 2020, from

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