Neotame vs Titanium Dioxide: which is worse?

What is Neotame?

Neotame is a synthetic dipeptide sweetener — a derivative of aspartame with a 3,3-dimethylbutyl group added to block aspartame's metabolism, preventing the release of phenylalanine. This means it is safe for people with phenylketonuria (PKU), unlike aspartame. It is approximately 7,000-13,000 times sweeter than sucrose.

What is Titanium Dioxide?

Titanium dioxide (TiO2) is a naturally occurring white mineral used as a food colorant, whitening agent, and opacity enhancer. In food applications, it exists as nano-sized and micro-sized particles. It is one of the most widely produced industrial minerals globally, used in paints, plastics, sunscreens, and food products.

Documented risks

Neotame: Neotame is one of the newer synthetic sweeteners with a shorter safety track record. A 2023 study published in Frontiers in Nutrition found that neotame damaged intestinal epithelial cells in vitro and disrupted the gut microbiome in mice — including reducing beneficial bacteria and increasing bacterial invasion of intestinal cells. The study observed effects at concentrations that could be achievable through high consumption of neotame-containing products. The FDA has set an ADI of 0.3 mg/kg/day, one of the lower sweetener ADIs, reflecting a conservative safety margin. Limited long-term human safety data exist compared to aspartame, acesulfame K, or saccharin, which have been used for decades. EFSA's 2010 opinion found no safety concern at permitted levels. The Frontiers in Nutrition 2023 gut study represents new concerning findings that warrant further investigation.

Titanium Dioxide: The EU banned titanium dioxide as a food additive in 2022 following EFSA's landmark 2021 safety assessment (EFSA Journal 2021;19(5):6585), which concluded that titanium dioxide 'can no longer be considered safe as a food additive.' The primary concern is genotoxicity from nanoparticles: EFSA determined it was impossible to rule out the risk of DNA damage (genotoxicity) from TiO2 nanoparticles at typical food use exposure levels. In vitro studies have demonstrated that TiO2 nanoparticles cause DNA strand breaks in intestinal epithelial cells and induce oxidative stress. A 2019 study in Nature Communications found TiO2 nanoparticles could disrupt gut microbiome balance and intestinal barrier function in mice models. Multiple studies have suggested effects on gut permeability and immune function. IARC classifies titanium dioxide as Group 2B (possible human carcinogen) for inhalation exposure in occupational settings — primarily relevant to workers handling TiO2 dust, based on rat lung cancer studies. While inhalation and oral exposure are different routes, EFSA determined that the genotoxicity concerns from nanoparticles applied to oral food use as well. Following the EU ban, California attempted to pass legislation banning TiO2 in candy (along with other additives) in 2022. The bill was signed in modified form. Mars reformulated EU Skittles to remove TiO2. The US FDA has not announced specific action on food-grade TiO2 as of 2025, though USRTK and other organizations are calling for a US ban.