Not so sweet: Chemical in common artificial sweetener found to damage DNA

A new study has found that consuming a widely available artificial sweetener produces a chemical that is damaging to DNA. The findings raise concerns about whether the sweetener is a contributing factor to a number of health problems.

The artificial sweetener in question is sucralose, sold under the brand name Splenda. Sucralose is 600 times sweeter than sugar and can be found in many baked goods, soda, chewing gum, gelatins, and frozen dairy desserts. A 2020 study showed that Splenda was easily Americans’ most preferred sugar substitute, with 51.4% of the population using it. The next popular was Sweet’N Low, which contains saccharin, at 25%.

North Carolina State University researchers looked particularly at sucralose-6-acetate, one of the fat-soluble compounds produced when sucralose is broken down (metabolized) in the body, to determine how it affects the body, particularly DNA. They’d already studied sucralose metabolism back in 2018, which is how they knew about the existence of sucralose-6-acetate.

In their current study, the researchers conducted a series of lab experiments on human blood cells by exposing them to sucralose-6-acetate and analyzing them for markers of genotoxicity, or damage to DNA.

“In short, we found that sucralose-6-acetate is genotoxic, and that it effectively broke up DNA in cells that were exposed to the chemical,” said Susan Schiffman, corresponding author of the study.

They found that the chemical was clastogenic; that is, it directly caused DNA strand breakages. If left unrepaired or improperly repaired by the body, damaged DNA strands can lead to cancer. And their testing showed that sucralose-6-acetate negatively affected human gut tissues.

“Other studies have found that sucralose can adversely affect gut health, so we wanted to see what might be happening there,” said Schiffman. “When we exposed sucralose and sucralose-6-acetate to gut epithelial cells – the tissue that lines your gut wall – we found that both chemicals cause ‘leaky gut.’ A leaky gut is problematic because it means that things that would normally be flushed out of the body in feces are instead leaking out of the gut and being absorbed into the bloodstream.”

The researchers examined the genetic activity of gut cells to see how they were affected by the presence of sucralose-6-acetate.

“We found that gut cells exposed to sucralose-6-acetate had increased activity in genes related to oxidative stress, inflammation and carcinogenicity,” Schiffman said.

Oxidative stress occurs when there are too many unstable molecules called free radicals in the body and insufficient antioxidants to get rid of them. It can damage fatty tissues, DNA and proteins, which, in turn, can lead to diseases such as diabetes, hardening of the blood vessels (atherosclerosis), high blood pressure and heart disease, and cancer. Inflammation is associated with cardiovascular disease, inflammatory bowel disease, asthma, depression and auto-immune diseases such as rheumatoid arthritis. Carcinogenicity refers to the ability of a chemical substance or mixture of substances to cause cancer or increase its incidence.

Of concern to the researchers was that off-the-shelf sucralose contained trace amounts of sucralose-6-acetate.

“To put this in context, the European Food Safety Authority has a threshold of toxicological concern for all genotoxic substances of 0.15 micrograms per person per day,” Schiffman said. “Our work suggests that the trace amounts of sucralose-6-acetate in a single, daily sucralose-sweetened drink exceed that threshold. And that’s not even accounting for the amount of sucralose-6-acetate produced as metabolites after people consume sucralose.”

In the US, the Food and Drug Administration (FDA) regulates the use of sweeteners, including sucralose. By law, like all other food additives, sweeteners must be deemed safe for consumption before they’re added to food or beverages. The acceptable daily intake of sucralose recommended by the FDA is 5 mg per kilogram (2.2 lb) of body weight. So, for a 150 lb (68 kg) person, 340 mg a day is considered safe. A packet of Splenda contains 12 mg of sucralose. According to the FDA’s website, they monitor “the latest science available on sweeteners” to determine their safe use.

Sucralose has also been deemed safe by other food safety regulatory bodies, including the Joint FAO/WHO Expert Committee Report on Food Additives, the Health Protection Branch of Health and Welfare Canada, and Food Standards Australia New Zealand.

However, the researchers say their study’s findings are a general warning to regulators and the public.

“This work raises a host of concerns about the potential health effects associated with sucralose and its metabolites,” Schiffman said. “It’s time to revisit the safety and regulatory status of sucralose, because the evidence is mounting that it carries significant risks. If nothing else, I encourage people to avoid products containing sucralose. It’s something you should not be eating.”

The study was published in the Journal of Toxicology and Environmental Health, Part B.

Source: North Carolina State University