What is Aspartame?

Aspartame is an artificial noncarbohydrate sweetener discovered in 1965 by James Schlatter. Although it is low in calories (4 calories/gram) but is 200 times sweeter than the normal sugar (1). The chemical name of aspartame is N-l-α-aspartyl-l-phenylalanine 1-methyl ester. This article is about aspartame and health risk and whether is aspartame really carcinogenic.

Various carbonated and powdered soft drinks, beverages, chewable multivitamins, breakfast cereals, chewing gum, puddings and fillings, yogurt products, and over 500 pharmaceutical products have been using this compound since 1980. Not only does it mimic the taste of sugar but also enhances the fruity delights like cherry and orange.

Approved by the Food and Drug Administration (FDA)

How much aspartame can be consumed daily?

The acceptable daily intake (ADI) of aspartame is currently 50 mg/kg body weight in the United States (US FDA FDA) while the JECFA (Joint FAO/WHO Expert Committee on Food Additives) has set this value as 40 mg/kg of body weight/day for both children and adults.

Is Aspartame safe to consume?

There is a huge debate going on all over the world about Aspartame and its health risk or whether is aspartame really not good or carcinogenic.

In the month of July 2023, the International Agency for Research on Cancer (IARC)  along with the WHO released a joint statement about aspartame

• Classified Aspartame as possibly carcinogenic to humans (Group 2B) on the basis of limited evidence for cancer in humans (specifically, for hepatocellular carcinoma, which is a type of liver cancer).
• There was also limited evidence for cancer in experimental animals and limited evidence related to the possible mechanisms for causing cancer (4).

The simple answer to the question of whether Aspartame is safe to consume is Yes if you are taking it in limited amounts that is an established acceptable daily intake (ADI) of 0–40 mg/kg body weight for aspartame.

The committee therefore reaffirmed that it is safe for a person to consume within this limit per day.

For example: With a can of diet soft drink containing 200 or 300 mg of aspartame, an adult weighing 70kg would need to consume more than 9–14 cans per day to exceed the acceptable daily intake, assuming no other intake from other food sources (5).

Health Benefits of Aspartame

1. Treat Osteoarthritis

Aspartame contains bioactive compounds that act as an anti-inflammatory agent that is effective in relieving pain caused by chronic inflammation of the joints, reduces the formation of blood clots and fever thus has antithrombotic, antiarthritic properties (6, 7).

2. Nongenotoxic properties

According to the European Food Safety Authority (EFSA), aspartame does not contain any genotoxic activity (damage the genetic information like DNA) thus aspartame has no potential for mutagenic or genotoxic activity (8).

How aspartame broke down in the body

Aspartame = Phenylalanine (50%) + Aspartic acid (40%) + Methanol (10%)

Its safety profile is much better than that of saccharin or cyclamate.

When absorbed by the body mainly in the gut.

• Aspartic acid is transformed into alanine plus oxaloacetate
• Phenylalanine is transformed mainly into tyrosine and, to a lesser extent, phenylethylamine, and phenyl-pyruvate.
• Methanol is transformed into formaldehyde and then to formic acid.

Aspartame and health risk

Following are some of the health risks related to aspartame consumption.

1. Risk of allergy

Consumption of aspartame may cause some allergic reactions due to the presence of diketopiperazine, methanol, and formaldehyde, or its metabolite. Like anaphylaxis, contact dermatitis, and induce hives which can be acute, delayed, or chronic when aspartame decomposes (9, 10).

2. Unstable in high temperature

Aspartame is not stable under certain conditions including baking and cooking (86^◦ F) and prolonged exposure to acid conditions generates formic acid, which in turn causes metabolic acidosis.

Moreover, on heating aspartame converts its component amino acids (phenylalanine and aspartic acid), methanol as well as diketopiperazine and loses its sweetness which methanol toxicity imitates multiple sclerosis, leading to death (11).

3. Risk of Cancer

A research study suggested that aspartame consumption has no significant carcinogenic effect thus the intake of low as well as high amounts of aspartame is not associated with the risk of cancer (12).

Another study on rats suggested that exposure to aspartame in the fetus, as well as an adult, increases the risk of lymphoma, leukemia, urinary tract tumors, and neurological tumors. Even at a daily dose (20 mg/kg) that is much less than the acceptable daily dose (40 mg/kg) there is a lack of data about the effect of aspartame on humans (13, 14).

4. Phenylketonuria

The person who is already suffering from phenylketonuria should avoid intake of aspartame because it contains phenylalanine which is not metabolized and then builds up to dangerous levels in their brains (15).

5. Harmful for brain development

If you are pregnant or a lactating mother or have infants you should avoid or use utmost caution of aspartame. Because it reduces the body weight of developing organisms, produces anxiety-like behavior, and causes injury to the brain in several ways including memory impairments (16).

Intake of aspartame increases the levels of phenylalanine, tyrosine, and aspartic acid in the brain which blocks the transport of important amino acids to the brain. It also reduces levels of dopamine and serotonin, causes hyperexcitability of neurons, and leads to the death of neurons (17).

Aspartame is responsible for central nervous system depression, vision disorders, and other symptoms leading ultimately to metabolic acidosis and coma by alteration in brain neurotransmitter concentrations (18).

Furthermore, consumption of a high amount of aspartame (30 mg/kg/day for 7 days) may cause other neurological diseases such as Alzheimer’s disease, Parkinsonism, multiple sclerosis, headaches (migraine), insomnia, seizures, learning problems, irritable moods, anxiety as well as depression. Therefore, excessive aspartame ingestion may be involved in certain mental disorders and also misbalance learning and emotional function (19, 20).

6. Aspartame is not good for the heart

One of the main side effects of aspartame is produces an excessive amount of reactive oxygen species that damage DNA and reduce cardiac function thus aspartame may be toxic to the heart (21).

7. Damage liver

Aspartame increases the activity of some enzymes in the liver which disturbs the lipid profile levels, increases oxidative stress due to the production of excessive free radicals, and affects the liver and kidney (22, 23).

However, another study suggested that aspartame (15 mg/kg) is safe for a person who is suffering from alcoholic stable liver disease therefore use of aspartame is controversial (24).

8. No effect on an obese and diabetic person

Aspartame consumption does not affect blood glucose levels, insulin levels, total cholesterol, triglycerides levels, and body weight however it increases high-density lipoprotein cholesterol serum levels. Thus intake of aspartame does not support a beneficial effect on diabetes and obesity (25).

9. Risk of fibromyalgia

Some people experience wrist, hand, and cervical pain as well as fatigue after ingestion of aspartame however these symptoms have been undergone after the removal of aspartame from diet thus patients who are suffering from fibromyalgia should avoid intake of aspartame (26).

10. Aspartame Cancer

Other aspartame and health risk are carcinogenic effects in rats. Other studies suggested that aspartame is not associated with an increased risk of cancer in humans thus we can say that aspartame is safe. 

What is so bad about aspartame?

Aspartame and health risk mainly depends upon the consumption in the human diet for long-term will affect the nervous system, cardiac, liver, kidney behavioral, and genetic functions thus it is recommended to restrict or avoid the use of aspartame as much as possible, and if it is necessary, decrease the dose (27, 28).

Is aspartame a poison?

Aspartame itself is not poison but yes amount of aspartame and health risk both are related. When consumed it gets converted into toxic components. It is metabolized in the gastrointestinal tract and converts into its toxic components like aspartic acid, phenylamine, and methanol. In which phenylalanine plays an important role in neurotransmitter regulation. It further breaks into dopamine, norepinephrine, and epinephrine. Which is responsible for hyperthyroidism, or overactive thyroid, pulmonary hypertension, systemic hypertension, and irregular heartbeat (either too slow or too fast) (29). Aspartic acid and their precursor glutamate, asparagines, and glutamine cause hyperexcitability of neurons in the central nervous system. Moreover, methanol is converted into formate, which can either be excreted or give rise to formaldehyde, diketopiperazine (a carcinogen), and a number of other highly toxic derivatives. However, aspartame is not considered a poison but you should avoid excessive consumption of aspartame (30).

Will aspartame kill you?

Nope, there is currently no evidence to suggest that aspartame causes death. However, it acts as a chemical stressor that increases plasma cortisol levels in the brain and may alter gut microbiota. Also may disrupt the oxidant/antioxidant balance, induce oxidative stress, and damage cell membrane integrity, and other health problems (31, 32).

Is aspartame safe?

Aspartame is safe for regular consumption however it should be used in the recommended fashion. High dosage may have a negative effect on the organ system.

How much aspartame is too much?

These “diet” sodas, along with thousands of other products containing aspartame. Diet sodas contain 50-125 mg of aspartame and the accepted daily intake of aspartame by FDA, FAO/WHO is 40-50 mg/kg. Thus you can consume 16 cans per day of diet coke without any side effects.

Let’s take a closer look at some products that contain aspartame (33,34)

Q&A