On July 14, 2023, the International Agency for Research on Cancer (IARC, affiliated with the World Health Organization [WHO]) announced that aspartame, a common artificial sweetener found in thousands of beverages and processed foods, is a possible carcinogen. You may recognize aspartame by the brand names NutraSweet and Equal. This artificial sweetener, along with others, are popular among women in perimenopause and menopause because they provide sweetness without calories. However, artificial sweeteners are not healthy for women in menopause.

The FDA disagrees with the IARC’s conclusion about aspartame, saying that the studies they used had “significant shortcomings.” 

Read about menopause and artificial sweeteners

What is aspartame?

This artificial sweetener is known in scientific circles as L-aspartyl-L-phenylalanine methyl ester. It is composed of two amino acids, aspartic acid and phenylalanine, and is about 200 times sweeter than table sugar. Aspartame was approved by the US Food and Drug Administration (FDA) in 1982 and is used in many diet beverages and a wide variety of processed foods ranging from salad dressings to candy, ice cream, and other items. Aspartame is also available in packets to be used in coffee, tea, and is added to foods such as cereals and smoothies. 

The current Acceptable Daily Intake (ADI) of aspartame approved by WHO, Health Canada, and the European Food Safety Authority is 40 mg/kg of body weight. An adult who weighs 184 pounds (83 kg) would reach that limit by consuming 33 cans of a diet soft drink in a day. In the US, where the ADI is 50 mg/kg of body weight, someone could drink 40 cans to reach that limit. 

Aspartame and cancer risk

Many studies have found an association between aspartame use and cancer risk. In a 2021 study entitled “Aspartame and cancer—new evidence for causation,” for example, the authors conducted an immunohistochemical and morphological re-evaluation of original animal research and aspartame. They confirmed that aspartame is a carcinogen in rodents and that prenatal exposure to the chemical increases cancer risk in rodent offspring. Their conclusions lead them to “encourage all national and international public health agencies to urgently reexamine their assessments of aspartame’s health risks” and for “food agencies to reassess Acceptable Daily Intake” levels for aspartame.

The results of a large study that included nearly 103,000 individuals were published in 2022. The authors found that compared with nonconsumers, those who had higher intake of artificial sweeteners (especially aspartame and acesulfame-K) had a greater risk of overall cancer. Higher risks were seen for breast cancer and obesity-related cancers. 

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Aspartame and other health risks

Women in perimenopause and menopause are at risk for other health issues related to use of aspartame and other artificial sweeteners. For example, you know when you are ingesting a beverage or food with aspartame or other artificial sweetener. However, the sweet taste can trigger what is known as cephalic phase insulin release, which may result in a small rise in insulin levels. 

Using artificial sweeteners on a regular basis also may modify your gut bacteria, which in turn can make your cells resistant to the insulin you make and lead to a rise in insulin and blood sugar levels. Both prediabetes and type 2 diabetes are common in menopause. An imbalance of gut bacteria also has an impact on digestion and immune function, both of which are already affected by hormonal changes in menopause. 

Researchers used data from more than 103,000 participants in the NutriNet-Sante cohort to determine the risk of stroke and heart attack associated with use of artificial sweeteners, including aspartame. The participants were followed for nine years. Evaluation of the data revealed that use of artificial sweeteners was linked to a 9 percent greater risk of any type of cardiovascular issue and an 18 percent greater risk of stroke.

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