Avobenzone vs Maltodextrin: which is worse?

What is Avobenzone?

Avobenzone (INCI: Butyl Methoxydibenzoylmethane) is a chemical UV filter that is the only FDA-approved broad-spectrum UVA-absorbing active sunscreen ingredient in the US that covers the full UVA spectrum (320–400 nm). It is inherently photounstable and must be combined with photostabilizers.

What is Maltodextrin?

Maltodextrin is a polysaccharide derived by partial hydrolysis of starch — most commonly corn starch in the US, but also wheat, potato, or rice starch. It is a white powder with a mild, slightly sweet taste and is highly soluble. Despite being classified as a carbohydrate, maltodextrin has a high glycemic index (GI of 85–105), often higher than table sugar.

Documented risks

Avobenzone: Avobenzone is effective and considered safe at approved concentrations (up to 3% in US OTC sunscreens). A 2019 FDA study found that several sunscreen actives including avobenzone were systemically absorbed above the 0.5 ng/mL threshold after repeated use, triggering a call for additional safety data. This does not indicate harm, but the FDA requested more studies under its proposed sunscreen monograph. Current evidence supports its continued safe use. No clear endocrine disruption or carcinogenicity at human exposure levels is established.

Maltodextrin: Maltodextrin's very high glycemic index (GI 85–105) means it causes rapid blood glucose spikes, potentially problematic for people with diabetes or insulin resistance. A 2012 study in PLoS ONE (Bhatt et al.) found that maltodextrin suppressed beneficial gut bacteria (like Lactobacillus) and increased Escherichia coli biofilm formation associated with Crohn's disease. A 2022 study in Nutrients noted maltodextrin's potential to disrupt gut microbiome composition at typical dietary intakes. Regulatory agencies have not restricted its use, but nutrition researchers increasingly flag it as a low-quality carbohydrate.