Do you chew gum? Drink diet sodas or hot chocolate? Enjoy cereals? Then the odds are that you have also consumed aspartame, one of the most widely used artificial sweeteners in the world. It is prominently featured in “sugar free” products that are consumed by men, women and, of particular concern, children.

The US FDA approved aspartame (i.e. Nutrasweet®, Equal®, Sugar Twin®) for use in foods in 1981 after reviewing a few preliminary animal studies (each using approx 40 female and 40 male rats) which appeared to show that aspartame safe. It was quickly embraced by food and beverage manufacturers as a “sugar free” option and is now found in more than 5000 foods. Yet, do we really understand the risks? Was the research that led to the FDA approval adequate? Perhaps not.

Multiple Studies Find Cancer Risk

In 1997, the Ramazzini Institute (an Italian research laboratory)  performed a “mega experiment” studying hundreds of rats from birth to their natural death due to old age to study the impact of aspartame exposure over time.(1,2)

Their results found an increase in the risk of lymphomas and leukemias, cancerous lesions of the renal pelvis and ureters, malignant schwannomas of peripheral nerves, lesions in the nose and malignant brain tumors. Their data also clearly established a dose response curve. The animals that received the highest doses of aspartame had the highest incidence of various cancers but, that said, even low doses of aspartame were found to be risky. These researchers were also able to demonstrate that if a pregnant mother was exposed to aspartame, this resulted in a  greater risk of cancer in their children. (3,4)

Yet, their research faced intense opposition. The European Food Safety Agency (EFSA) suggested that the animals in the study may have been compromised by Mycoplasma infections. They and other groups, journals and non-profit organizations endorsed the use of aspartame as generally safe for human consumption. Yet, at no point could any of the critics account for the dose response data.

In Spring 2021, the Ramazzini Institute released new data which strongly validates their initial finding and rules out the role of infection as a cause for lesions. (5) They used new “state-of-the-art technologies (immunohistochemical analysis, harmonized diagnostic classification) to identify cancerous lesions. The results are staggering.

Animals who received even low dose exposures that are close to the Acceptable Daily Intake (ADI) levels established by the USA and European Union  showed increased risk of cancer. They express concern for the infants and young children who, due to their small body size, often exceed the daily recommended amounts. “The Current ADI levels for aspartame may be set too high and may not offer sufficient protection against cancer.”

One deeply concerning finding was its effect in utero with infants. “This finding indicates that aspartame may initiate carcinogenesis in utero. It is consistent with a large body of literature indicating that young animals, especially in the fetal period, are more sensitive than older animals to a range of chemical and physical carcinogens.” 

Methanol and Formaldehyde

What is it about aspartame that appears to be carcinogenic? Aspartame is metabolized by the GI tract into three distinct chemicals: aspartic acid, phenylalanine and methanol. It is the methanol that immediately raises concerns. Known as wood alcohol, methanol is toxic to humans. Every year, hundreds die after drinking methanol around the world.  During COVID, you may have heard of several FDA warnings about hand sanitizers that were found to contain methanol.(5)

But, it’s how methanol is broken down that raises yet more concerns. It is transformed into formaldehyde and then formic acid in our bodies. We certainly know that aspartame can trigger IC flares (6) due, most likely, to the irritation caused by formic acid but the formaldehyde is much, much scarier. In 1987, the Environmental Protection Agency (EPA) classified formaldehyde as a “probably human carcinogen” under conditions of unusually high or prolonged exposure.(7) Could this correlate with people who have used aspartame daily, for years? The International Agency for Research on Cancer and the National Toxicology Program  also classify formaldehyde as a known human carcinogen.(8,9)

Employees exposed to formaldehyde at work, particularly  the funeral industry, are also at greater risk of developing myeloid leukemia.(10)  The more exposure a person had, the greater the risk of cancer. Similar results were also found in textile workers.(11)

Homeowners have unwittingly brought toxic formaldehyde into their homes if they purchase furniture and/or flooring made with particle board.  Lumber Liquidators® has paid millions of dollars in fines and penalties because they used flooring manufactured in China that off gassed dangerous levels of formaldehyde into consumer homes.(12)

Now imagine what the long-term consumption of aspartame could do?

We Must Protect Our Children

One of the mysteries confronting society today is why so many cancers are appearing, often in younger children. According to the American Cancer Society, about 10,500 children in the USA will be diagnosed with cancer in 2021.(13) Tragically, 1,190 children under the age of 15 are also expected to lose their fight with cancer this year.

Could this relate, in some way, with the widespread use of aspartame?  In 2017, the use of artificial sweeteners increased 200% in children and 54% in adults between 1999 and 2012. 44% of adults and 20% of children consume low calorie sweeteners more than once a day.

We must urge the FDA to review this latest research and, if supported, issue a cancer warning on aspartame containing products, especially those products that are potentially consumed by children and pregnant women. We must protect ourselves from chemicals which enrich corporations at the cost of our long-term health.

Aspartame sugar is on our IC “caution” list and with this new data, it will certainly stay there.


  1. Landrigan, P.J., Straif, K. Aspartame and cancer – new evidence for causation. Environ Health 20, 42 (2021).
  2. Soffritti M, Belpoggi F, Degli Esposti D, Lambertini L, Tibaldi E, Rigano A. First experimental demonstration of the multipotential carcinogenic effects of aspartame administered in the feed to Sprague-Dawley rats. Environ Health Perspect. 2006;14(3):379–85.
  3. Soffritti M, Belpoggi F, Tibaldi E, Degli Esposti D, Lauriola M. Life-span exposure to low doses of aspartame beginning during prenatal life increases Cancer effects in rats. Environ Health Perspect. 2007;115(9):1293–7.
  4. Soffritti M, Belpoggi F, Manservigi M, Tibaldi E, Lauriola M, Falcioni L, et al. Aspartame administered in feed, beginning prenatally through life span, induces cancers of the liver and lung in male Swiss mice. Am J Ind Med. 2010;53:1197–206.
  5. FDA Updates on Hand Sanitizers Consumers Should Not Use. 03/25/21
  6. Friedlander J. et al. Diet and its role in interstitial cystitis/bladder pain syndrome (IC/BPS) and comorbid conditions. BJU International. BJU Int. 2012 Jan 11
  7. U.S. Environmental Protection Agency, Office of Air and Radiation. Report to Congress on Indoor Air Quality, Volume II: Assessment and Control of Indoor Air Pollution, 1989
  8. International Agency for Research on Cancer (June 2004). IARC Monographs on the Evaluation of Carcinogenic Risks to Humans Volume 88 (2006): Formaldehyde, 2-Butoxyethanol and 1-tert-Butoxypropan-2-ol. Retrieved June 10, 2011, from:
  9. National Toxicology Program (June 2011). Report on Carcinogens, Twelfth Edition. Department of Health and Human Services, Public Health Service, National Toxicology Program. Retrieved June 10, 2011, from:
  10. Hauptmann M, Stewart PA, Lubin JH, et al. Mortality from lymphohematopoietic malignancies and brain cancer among embalmers exposed to formaldehyde. Journal of the National Cancer Institute 2009; 101(24):1696–1708. [PubMed Abstract]
  11. Pinkerton LE, Hein MJ, Stayner LT. Mortality among a cohort of garment workers exposed to formaldehyde: An update. Occupational Environmental Medicine 2004; 61:193–200[PubMed Abstract]
  12. Farmer B. Lumber Liquidators To Pay $33 million criminal penalty. Sixty Minutes. march 12, 2019.
  13. Key Statistics For Childhood Cancers. American Cancer Society.  January 12, 2021.