Story misses bigger picture of nitrate exposure, cancers.

In an April 20th Reuters article, Howard Wolinsky reports on research that showed a slight increased risk of developing ovarian cancer from eating processed meats that contain nitrates and nitrites as preservatives. The reporter missed telling readers important background information – that consuming nitrates and nitrites is associated with several cancers in addition to ovarian cancer.  By including the multi-cancer link, the journalist would have indicated to readers that this is not an isolated finding.

 

Dietary nitrates and nitrites come from several sources, including vegetables like spinach with high nitrate levels, processed meat products and drinking water contaminated with nitrates. 

 

Nitrate contamination is a particular problem for agricultural regions, particularly rural water supplies impacted by farming. Certain practices and products – applying nitrogen fertilizer, runoff from uncontained livestock, to name a couple of sources – release nitrogen-rich compounds into the environment where they make their way into surface and ground water.

 

Once in the body, nitrate and nitrite can be converted to cancer-causing nitrosamines. This is one reason that excessive nitrate intake – especially in combination with red meat – is associated with cancers of the colon, rectum, bladder, stomach, esophagus, and thyroid gland, as well as non-Hodgkin lymphoma. 

 

There is an important difference between nitrate intake from vegetables, as compared with nitrate intake from processed meats or drinking water. Vegetables contain vitamin C and several other plant-based compounds that inhibit the conversion of dietary nitrates and nitrites into nitrosamines. These cancer-fighting molecules are not present in meat or drinking water.

 

The reported research, in conjunction with other studies, strengthens the argument to eat a limited amount of processed meat, consuming fresh fruits and vegetables instead.  By informing readers about the bigger context of how nitrates and nitrites are associated with other types of cancers, the journalist would have made the new research more relevant to a broader audience.