One of the earliest methods for curing food involved the use of salt.
Salt prevents food spoilage through a process known as osmosis,
whereby it basically sucks the moisture out of the bacteria's bodies,
killing them by dehydration.
Sodium nitrate is a type of salt that happens to be a particularly effective
food preservative. A naturally occurring mineral, sodium nitrate is present
in all kinds of vegetables (root veggies like carrots as well as leafy greens
like celery and spinach) along with all sorts of fruits and grains.
Basically, anything that grows from the ground draws sodium nitrate out of the soil.
If this seems strange, remember that the word nitrate refers to a compound made
of nitrogen, which is the single biggest component of our atmosphere.
Every time you take a breath, you're breathing 78 percent nitrogen.
The soil itself is loaded with the stuff.
Nitrates and Nitrites
One of the things that happens when sodium nitrate is used as a curing agent is that
the sodium nitrate is converted to sodium nitrite. It's sodium nitrite that actually
possesses the antimicrobial properties that make it a good preservative.
Interestingly, the sodium nitrate that we consume through fruits, vegetables
and grains is also converted to sodium nitrite by our digestive process.
In other words, when we eat fruits, vegetables or grains, our bodies
produce sodium nitrite.
Nitrites and Cancer
Several decades ago, some researchers raised the possibility that nitrites could be
linked to cancer in laboratory rats. This suggestion received a lot of media attention.
What received less media attention, however, was when it turned out that they were
wrong. Indeed, the National Academy of Sciences, the American Cancer
Society and the National Research Council all agree that there's no cancer
risk from consuming sodium nitrite.