The preponderance of negative publicity about nitrates may cause you to wonder just how dangerous they are.

As discussed last month, nitrates, especially in conjunction with harmful bacteria, can be very dangerous to infants. Some also believe nitrates to be a contributing factor to cancer, though the scientific evidence showing such linkages is weak. There is actually much evidence that nitrates are good for us, though these reports usually do not get much publicity.

Nitrates' role in protecting health

BENEFICIAL BACON: The benefits of nitrates in food aren't publicized very much, but there is evidence that when they are converted in the human body into nitrites, they help widen blood vessels and improve immune function.

The human body actually converts nitrates (NO₃) into nitrites (NO₂), which are much more toxic then nitrates. Nitrites found in the human body play a key role in widening blood vessels and reducing clotting, and are associated with improved immune function and the ability to fend off infections. The human body actually manufactures nitrites from other nitrogen sources, such as proteins, in the absence of nitrate.

Approximately 80% of dietary nitrates come from vegetable consumption. A small lettuce salad contains about the same amount of nitrate nitrogen as a gallon of water containing the EPA limit of 10 parts per million of nitrate nitrogen.

What about hot dogs, bacon and other processed meats, you ask? These meats contribute about 5% of the nitrate in our diets, a much smaller amount than is commonly believed.

At one time, meats were cured with sodium nitrate, a common salt. About a century ago, scientists discovered that during the curing process, sodium nitrate was converted to sodium nitrite. Since that time, meat processors simply use sodium nitrite directly in curing meats. Since sodium nitrite was approved for use in cured meats in 1925, no cases of botulism have been associated with commercially prepared cured meats, according to the American Meat Institute.

On packages of bacon or hot dogs marked "no nitrates added," read the labels closely. You will find other ingredients that contain relatively high levels of nitrates naturally, like celery and beets. Using these ingredients provides the healthy benefits of preserving the meat without adding sodium nitrate or sodium nitrite salts.

Cancer connection?

All of the fears associated with nitrates and cancer, in my view, are overblown. We do know that when meats containing nitrites are heated to more than 265 degrees, some of the nitrite is converted to nitrosamines, a known carcinogen. There is good reason to limit your consumption of charred foods.

Link to do with water quality?

Public water suppliers devote many resources to meeting the U.S. drinking water standard of 10 ppm nitrate nitrogen. Perhaps these resources would be better used to address actual toxic substances, such as lead, mercury and other toxic pollutants, many of which are much more alarming because they accumulate in the body.

Nitrate, on the other hand, does not accumulate. It is simply used by the body and ultimately digested.

It is important to remember a few keys points about nitrates. Make sure you periodically test your private well for both nitrates and bacteria, and be knowledgeable of the risks to infants. For humans beyond infancy, nitrates have been shown to be safe, even beneficial.

Keep in mind, too, that evaluation of the nitrate levels in vegetables, meats and well water suggests that current water limits may be overly cautious and needlessly alarming.

Just don’t burn the bacon!

Formo is executive director with the Minnesota Agricultural Water Resource Center. For more information about MAWRC, visit its website, mawrc.org.