In October 2104, Howard and I embarked on a long, high, difficult six week trek in the remote Dolpo region of Nepal. Our guide, KB, was brilliant - young, fit, strong and clever, he spoke excellent English and we enjoyed his company. However, on the 14th day of the trek, KB admitted he was having terrible trouble sleeping at night. The problem had started on the first night of the trek and was getting worse. He had also become extremely sensitive to night noises such as barking dogs. He didn't have to tell us that because we’d already noticed that he would spend his nights throwing rocks at noisy dogs and even, rather bizarrely, ask mule train and pack horse drivers to remove the bells from their animals' necks.

This was a puzzle. Insomnia and hyperacusis – an increased sensitivity to everyday sounds - are commonly associated with some food additives and natural food chemicals, but I knew what KB ate because we were eating the same: additive free local foods mostly roasted barley flour porridge and two big serves a day of rice, lentils and vegetables. I checked that his drinks were okay, mostly water and weak milky tea, and that he wasn't using chewing gum.

Then I asked about toothpaste. You have to consider everything that people put in their mouths because additives can be absorbed through skin, whether you swallow the toothpaste or not. KB looked stunned. We read the label on his toothpaste. Bingo. It contained five colours, but even I couldn’t tell what they were, because toothpaste labelling is not covered by the same rules as food. It is one of the dirty tricks that manufacturers use to hide nasty additives from concerned consumers: they use Colour Index numbers. So the list read “colours mica/CI 77019, CI 16255, CI 17200, CI 177491, CI 77891”.

toothred

I usually look those numbers up on our website, but here we were in one of the most remote places on the planet and I didn’t have access. We could see the toothpaste was red. Get rid of it, I suggested. “But it is recommended by the World Dental Federation”, KB said.

Out went the toothpaste and KB’s problem disappeared overnight. I later confirmed that one of those numbers is artificial colour E124. When used in European food, it has to carry a warning about adverse effects on children's behaviour and attention, Another one - naphthalene red - isn’t even permitted in food, so no one knows what the side effects might be.  I was furious with toothpaste manufacturers, governments and therapeutic goods regulations for permitting this confusing labelling, and with the dentists in the World Dental Federation for endorsing such a product.

There was one fact I wanted to look up when we got back. What exactly is the World Dental Federation? Turns out it’s a professional group that runs congresses for dentists, and it is funded by …  wait for it … the same multinational company that makes KB's toothpaste. - Sue Dengate

toothFDI

More information: http://fedup.com.au/factsheets/support-factsheets/toothpaste