Artificial Sweeteners

These sugar substitutes are generally preferred because they are sweeter than sugar and can be used in smaller amounts while still getting a sugary taste. Though generally regarded as safe, sugar substitutes can cause flare-ups for individuals with bowel disease, and researchers are investigating how these substances affect gut microbiome health. Aspartame can also cause health issues for individuals with a rare genetic disease called phenylketonuria.

Some research suggests that certain sweeteners can throw off the balance of beneficial bacteria in the gut and shift the composition of the microbiome. Such changes, depending on an individual's specific gut flora and levels of sweetener consumption, could potentially affect metabolism and glucose tolerance or lead to bloating and diarrhea.

This US Food and Drug Administration graphic compares different approved sugar alternatives to give the public a sense of just how intensely sweet these sweeteners are compared to table sugar. Aspartame (NutraSweet and Equal), for example, is 200 times sweeter, Sucralose (Splenda) is 600 times sweeter, and Saccharin (Sweet'N Low) is between 200 and 700 times sweeter.

The agency states in this PDF graphic that a person weighing about 132 pounds would have to consume roughly a couple dozen sweetener packets daily—or more—to reach unsafe levels of consumption. The accumulated consumption would be across all sources, including diet beverages, sugar-free candies, and actual packets added to coffee.

The product, commonly known as Sweet'N Low, was banned in Canada in the late 1970s due to research indicating that the sweetener could cause cancer in lab rats. Subsequent studies have found that the rodent findings didn't hold true for humans, and so Canadian regulators state that they are considering updating their stance to allow the product to be added to certain foods (the product is currently allowed in the US).

Research published in 2014 from a randomized controlled study found that, on average, people only lost about two pounds if they switched to consuming artificial sweeteners instead of sugar. Some individuals using artificial sweeteners also have gained weight. Scientists theorize one potential explanation for this is that the sweeteners alter gut microbiomes in ways that reduce beneficial flora that would help promote digestion.

The International Agency for Research on Cancer, an arm of the World Health Organization, labeled aspartame—the artificial sweetener in Diet Coke—as one of several hundred possible cancer-causing substances in 2023. The determination was based on animal and human studies and "limited" evidence linking it to liver cancer. The WHO and US Food and Drug Administration both say the substance is safe at moderate levels. The FDA says a person weighing about 132 pounds would need to have 75 packets daily to reach an unsafe level.

This French study analyzed online periodic self-reported food journals from more than 100,000 people for a median of almost eight years and linked aspartame consumption to a roughly 15% increased cancer risk. It found that the people who consumed higher levels of aspartame had elevated cancer numbers—particularly breast and obesity-related cancers.

The product was known as "sugar of lead." It was made by boiling wine in lead pots, concentrating the grapes' natural sugars and adding sweetness from the lead that leached into the grapes. The substance was used until roughly the 1880s for medicinal purposes and also to sweeten wine. (Some users may encounter a paywall.)

The substance was discovered by chemists in 1878, but its use became more common during World War I and also afterward as a result of sugar rationing. It had become a typical household item in the US and Europe by 1917. During World War II, the artificial sweetener again saw significant popularity.