What Do Food Additives Do to Us?

Michael Greger (0:00)

We have lots of choices to make about our diet. Add to that doing the right thing when it comes to treating a chronic disease, fighting a virus, or losing weight. And suddenly, our nutrition choices can seem almost overwhelming. Well, I'm here to help. Welcome to the Nutrition Facts Podcast. I'm your host, Dr. Michael Greger. In our first story, we look at how many food additives banned in Europe remain legal in the US with our former research scientist, Dr. Christine Dennis.

Christine Dennis (0:33)

Food-grade titanium dioxide, also called E171, is used extensively in food products as a whitening agent in things like chewing gum and some maybe not-so-obvious products like baked goods and candy. In a survey of foods from a US grocery store, white frostings, coffee creamers, and chewing gum had the highest concentrations, followed by some candies, almond and rice milks, and dairy products like skim milk, sour cream, and yogurt. And the tricky part in the US is food additives like titanium dioxide are allowed to be listed generally as color-added, or as an anti-caking agent or filler, so you may not actually know what foods contain it.

This is exactly what the food survey found. High amounts of titanium dioxide in some foods with no labeling indicating the product even contained titanium dioxide. The only reason we care is because of risk. Titanium dioxide has been approved as a safe color additive for use in foods and drugs in the United States since 1966, and the European Union since 1969, until the European Food Safety Authority, known as EFSA, concluded in 2021 that titanium dioxide, E171, can no longer be considered safe as a food additive. What changed? Based on all the evidence available, a concern for genotoxicity, damage to our DNA, could not be ruled out. As a result of this report, the European Union prohibited its use as a food additive in August 2022 Since the 2021 report was issued, the US Food and Drug Administration has been petitioned to no longer allow the use of titanium dioxide in foods, but that is still pending. Other international food regulatory organizations like those in the United Kingdom, Canada, Australia and New Zealand also do not agree with EFSA's assessment and still allow titanium dioxide in foods.

Why all the differing opinions? The FDA notes that some of the genotoxicity tests considered by EFSA don't represent the titanium dioxide used in foods. Food-grade titanium dioxide is a mixture of microsized particles and nanosized particles. Nanoparticles are tiny materials ranging in size from 1 to 100 nanometers. That's about 100,000 times smaller than a human cell, which is what the genotoxicity studies in animals were done with. A common theme voiced by those disagreeing with EFSA is that you can't compare nanoparticle toxicity studies where researchers mixed and disperse the nanoparticles in a fluid with titanium dioxide in foods that rely on bigger microparticles for the desired color appearance.

What about the 40% nanoparticles? Well, when you mix nano and microparticles together, a nano might glom onto a microparticle, so it might not have the same effect as a straight nanoparticle.

So on the one hand, the European Union considers no amount of food-grade titanium dioxide in food to be safe, banning its use and setting off a worldwide chain reaction with bans in other countries including Switzerland, Qatar, and most recently Turkey. Meanwhile, other countries including the US, UK, and Canada don't consider the evidence for a ban compelling. DNA damage isn't the only problem though. Very little of the titanium dioxide we eat is actually absorbed. But when it is, it may just sit there and accumulate over time. But what happens to the 99% that isn't absorbed? It ends up in our colons where it can damage colon cells, and this is the food grade additive. It may also have adverse effects on our gut microbiome based on studies using just titanium dioxide nanoparticles, as well as the mixed version used as a food additive. There are non-toxic ways for food companies to whiten their products like rice starch or rice flour, but for the same effect more needs to be used, increasing costs.

If you live in a country like the US where it's still legal, what should you do? In my mind, there should be an extremely high bar for safety for cosmetic additives, and that's what titanium dioxide is, basically white food coloring. Since it is in no way necessary and tends to be used in ultra-processed junk food, we recommend trying to avoid it. Even if it were eventually exonerated, it would still be better to use soy milk than dairy coffee creamer, and to choose oatmeal over powdered donuts.

Michael Greger (5:04)