Nitrates and nitrites in plants


Why are nitrates harmful?

Nitrates are one of the major problems of water pollution. Most of the nitrates come from fertilizers. These seep into aquifers and contaminate water.

When we drink water contaminated with nitrates, these are converted into nitrites by the action of intestinal bacteria. They are also responsible for the appearance of nitrosamines.

Nitrosamines from nitrites

Nitrosamines are formed in the body by the action of the digestive acids. When we fry food at a high temperature, this can also be responsible for nitrosamine formation. Nitrosamines are thought to be one of the main reasons for the development of gastric tumors.

The maximum permitted level of nitrates is 5 mg per liter. Larger quantities can cause the blue baby syndrome, which is a disease caused by lack of oxygen which leads to the coloration of the skin.

This condition occurs because the nitrates, converted to nitrites, inhibit the absorption of oxygen.

Food high in nitrates


Spinach are one of the foods that can contain a lot of nitrates

Besides polluting water, the use of nitrogen fertilizers pollutes soil, so that these components are absorbed by the body through food, either plant food or animals that feed on plants.

If we consider that there are some vegetables that have a special ability to capture these components, we will realize the need to control the intake of certain foods in population groups that can be especially affected by this problem, such as children or aging people.

Among the main foods that can absorb nitrates easily we have: chard, spinach, beet or carrots.

Among the animal food richest in nitrosamines we have fish, beer and meat or cheese preserved in nitrite salt.

Tobacco smoke also contains lots of nitrosamines.

How to get rid of nitrates in water

To eliminate these substances different processes of filtration or water treatment have been used. It is known that activated carbon filters are not able to remove these components.

They get eliminated through a reverse osmosis system, although it should be noted that this procedure, in addition to eliminating all harmful products of water, also removes minerals that are beneficial to health, such as magnesium or calcium.

How to diminish nitrates in plant-based foods

boiled spinach and potatoes

boiled spinach and potatoes. We can eliminate much of nitrosamines from food by means of boiling it in water and draining it. Naturally, we should better discard the boiling water.

In order to diminish the nitrates of plants that especially accumulate them, a series of precautions should be taken into account when we prepare or eat these vegetables:

  • The best way is cooking them in water, so that it dissolves the nitrate content. Before cooking we should let them soak for a while for the same purpose.
  • Cooking water should be discarded and drained much as possible.
  • Cook as quickly as possible to prevent bacteria from acting against them by converting nitrate to nitrite and nitrosamines, which are the most harmful substances.
  • No consumption abuse, alternating them with other vegetables.

Antioxidants to combat nitrates

Another way of reducing nitrates effects on human body is to ingest rich antioxidant food. Antioxidants are able to neutralize the negative effects of these harmful substances. (More information about antioxidants)

punto rojoMore information on water.

This article was endorsed by Elisenda Carballido - Dietitian nutritionist. Postgraduate in Phytotherapy and master in Nutrition and Metabolism.
Written by Editorial Botanical-online team in charge of content writing

22 April, 2019

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