Mexican researchers sought to evaluate the effects of E171 across a span of conditions in mice, including its influence on behavior, along with the effects on the colon and liver. The research, published in 2020 in the journal Food and Chemical Toxicology, showed that E171 promoted anxiety and induced adenomas, or noncancerous tumors, in the colon. They also found that E171 heightened goblet cells hypertrophy and hyperplasia, which is typically seen in asthma patients and triggered by smoking or external pollutants and toxins. They also noted mucins overexpression in the mice, which can be linked to cancer cell formation. 

Overall, the Food Directorate's comprehensive review of the available science of TiO₂ as a food additive showed:

There seems to be a lot of misunderstanding about titanium dioxide, which can be used as a colorant in foods. While headlines may suggest titanium dioxide is a health concern, scientific research has actually shown titanium dioxide to be safe. So what is it used for and why is it used? Read on to learn more!

Other food manufacturers use titanium dioxide to absorb water and keep moisture from clumping or degrading, Paul Westerhoff, PhD, an environmental engineer at Arizona State University who researches the biological and cellular effects of titanium dioxide, told Health.

The realization of neuromorphic resistive memory in TiO₂ thin films (Strukov et al., 2008) marked an important milestone in the search for bio-inspired technologies (Chua and Kang, 1976). Many research proposals urged a focus on memristivity as the common feature of two electrical models: (i) electromigration of point defects in titanium oxide systems (Baiatu et al., 1990; Jameson et al., 2007) and (ii) voltage-gated ionic channels in the membranes of biological neurons (Hodgkin and Huxley, 1952). In this regard, memristors functionally mimic the synaptic plasticity of biological neurons, and thus can be implemented in artificial and hybrid neural networks. This includes a new paradigm of future computing systems (Zidan, 2018) and biocompatible electronics such as biointerfaces and biohybrid systems (Chiolerio et al., 2017).