Controversial since its approval in 1981, aspartame is one of the most studied human food substances.

The concern that aspartame causes cancer has been around since the ’80s, and it gained momentum in the mid-90s after the invention of the internet.

Most of the information circulating online at that time was found to be anecdotal, but to this day, people still worry about whether or not aspartame can cause cancer.

Currently there’s some mixed evidence on aspartame and its possible link to cancer, which we’re going to discuss here.

Two main types of studies are used to find out if a substance causes cancer: animal studies and human studies.

It’s important to remember that neither is usually able to give definitive evidence. This is because the results of animal studies don’t always apply to humans and different factors can make human studies hard to interpret. This is why researchers look at both animal and human studies.

Studies that found a connection in animals

A study published in 2006 in the journal Environmental Health Perspectives suggested that very high doses of aspartame increased the risk of leukemia, lymphoma, and other types of cancer in rats.

Various regulatory bodies, including the Food and Drug Administration (FDA), European Food Safety Authority, and the U.K.’s Food Standards Agency ordered reviews of the quality, analysis, and interpretation of this study.

The study was found to have a number of flaws, including the doses given to the rats, which were the equivalent of 8 to 2,083 cans of diet soda daily. The issues found in the study were documented the following year in an issue of the same journal.

None of the regulatory agencies changed their stance on the safety of aspartame and concluded that aspartame is safe for human consumption.

Studies that found a connection in humans

A report released in 1996 suggested that the introduction of artificial sweeteners in the United States might be to blame for the increase in the number of people with brain tumors.

According to the National Cancer Institute (NCI), the increase in brain tumors actually began eight years before aspartame was approved and was found in people aged 70 and older, an age group not exposed to high doses of aspartame.

In 2012, a study of 125,000 people found a link between aspartame and an increased risk of lymphoma, leukemia, and multiple myeloma in men, but not in women. The study also found a link between sodas sweetened with sugar in men.

Due to the inconsistent effects on men and women, the researchers concluded that the links could be explained by chance. The scientists who conducted the study later issued an apology for the study, admitting that the data was weak.

Studies that didn’t find a connection in animals

A meta-analytic review published in 2013 reviewed 10 previous rodent studies on aspartame and cancer risk conducted before December 31, 2012. The review of the data found that aspartame consumption has no carcinogenic effect in rodents.

Studies that didn’t find a connection in humans

One of the largest studies on the possible link between aspartame and cancer was performed by researchers from NCI. They reviewed 285,079 men and 188,905 women ages 50 to 71 who participated in the NIH-AARP Diet and Health Study.

The researchers concluded that aspartame wasn’t associated with the development of brain cancer, leukemia, or lymphoma.

A 2013 review of evidence of other studies on aspartame consumption and various cancers also found no association between aspartame and cancer risk.

A systematic review of the link between artificial sweeteners and cancer in humans was conducted using data from 599,741 people from 2003 to 2014. It was concluded that the data didn’t provide conclusive evidence linking aspartame to cancer.

Aspartame is an artificial sweetener that’s made of aspartic acid and phenylalanine.

Aspartic acid is a nonessential amino acid naturally found in our bodies and in sugarcane. Phenylalanine is an essential amino acid, which humans get from sources like meats, dairy, nuts, and seeds.

When combined, these ingredients are 200 times sweeter than regular sugar and very low in calories.

The internet is full of claims of aspartame poisoning and aspartame side effects, suggesting that it causes serious conditions, such as Alzheimer’s disease, Parkinson’s disease, and attention deficit hyperactivity disorder.

Studies haven’t found any evidence to prove any of these claims or to link aspartame to any health problem.

The only confirmed health issue related to aspartame pertains to a rare genetic disorder called phenylketonuria (PKU) in which the body can’t break down phenylalanine. People are born with the condition — aspartame doesn’t cause it.

People with PKU can experience a buildup of phenylalanine in the blood that prevents important chemicals from reaching the brain. People with PKU are advised to limit their intake of aspartame and other products containing phenylalanine.

The Centers for Disease Control and Prevention acknowledges that some people may have an unusual sensitivity to aspartame. Aside from very mild reported symptoms, there’s no evidence that aspartame causes adverse health problems.

Aspartame and other artificial sweeteners are regulated by the FDA. The FDA requires that they be tested for safety and approved before they can be used.

The FDA also sets an acceptable daily intake (ADI) for each, which is the maximum amount a person can safely consume each day of their lifetime.

The FDA sets this number approximately 100 times less than the lowest amount that might cause health problems, based on animal studies.

The ADI set by the FDA for aspartame is 50 milligrams per kilogram of body weight. The FDA estimates that an adult who weights 132 pounds would need to consume 75 tabletop sweetener packets a day to meet the recommended ADI.

Unless you’ve been diagnosed with phenylketonuria or believe you have sensitivity to aspartame because it makes you feel poorly, you don’t need to limit how much you consume. Not consuming more than the ADI is safe.

Aspartame can be found in a number of foods and beverages. Some of these include:

  • diet sodas, such as Diet Coke and diet ginger ale
  • tea drinks, such as Diet Snapple
  • sugar-free jam, such as Smucker’s
  • flavor crystals and powders, such as Crystal Light
  • sugar-free Popsicles
  • sugar-free Jell-O pudding
  • sugar-free syrup

Artificial sweeteners are generally considered safe. There are also a number of other sugar substitutes on the market that aren’t technically considered artificial sweeteners, such as stevia products.

Manufacturers of many of these sugar substitutes call them “natural” to imply they are somehow safer or better for you, even though they’re still refined or processed.

There’s no evidence that proves some artificial sweeteners are safer than others, unless you have a medical condition that requires that you avoid certain ingredients, such as PKU.

Sugar alcohols, which are carbohydrates found in plant products and processed for use as a sugar substitute, can have a laxative effect when you have too much of them. Excessive consumption can also cause gas and bloating.

Some examples of sugar alcohols include:

Aspartame is considered safe and is approved by a number of regulatory agencies, including the FDA, the World Health Organization, and the Food and Agriculture Organization of the United Nations.

The American Heart Association, American Cancer Society, and the Academy of Nutrition and Dietetics have also given their approval.

If you prefer not to consume aspartame, there are other artificial sweeteners and sugar substitutes on the market. Be sure to read labels when buying foods and beverages.

Water is always a healthy option if you’re trying to cut back on drinks containing sugar or sweeteners.