Inside Mark I: The First Fighting Tank

Here’s what most American dentists won’t tell you: your mouthwash is destroying the bacteria your body actually needs. Listerine kills 99% of bacteria — and that’s the problem. It’s indiscriminate. It wipes out the nitrate-reducing bacteria your body uses to produce nitric oxide — one of the most important molecules for blood pressure, insulin sensitivity, and cardiovascular function. A Harvard-affiliated study that followed nearly 1,000 adults over 3 years found that people who used mouthwash t