Nitrates often get a bad reputation, but it’s important not to group all nitrates into the same category. As with many things in life, some nitrates are good for us while others are bad.
For example, nitrates found in beetroot juice assist in reducing blood pressure and improving exercise performance. Nitrates are also found in many medications to treat angina.
There are nitrates and nitrites. In nitrates, nitrogen is bonded to three oxygen atoms; in nitrites, nitrogen is bonded with two oxygen atoms. Both are legal preservatives used to reduce bacteria in many foods. But processed foods aren’t the only foods that contain nitrates and nitrites – vegetables can get them through the soil.
Leafy greens like spinach tend to be highest in nitrates, followed by carrots and celery. Organic foods tend to have lower levels of nitrates.
How nitrates are packed in vegetables and meat are entirely different, and this is what can affect whether they are carcinogenic or not.
Nitrates are typically safe and don’t get involved in chemical processes in the body. Nitrites are far more reactive. Much of the nitrites we take in are converted from nitrates as a result of bacteria in the mouth. In fact, using an antibacterial mouth wash can reduce the manufacturing of nitrites in the mouth.
When these nitrites are swallowed, they can react with the acidic environment in the stomach, which forms nitrosamines – some of these can be carcinogenic. Nitrosamines can also be produced through high heat cooking such as frying bacon.
Kate Allen of the World Cancer Research Fund explained, “It’s not so much nitrates/nitrites per se [that are carcinogenic], but the way they are cooked and their local environment that is an important factor. For example, nitrites in processed meats are in close proximity to proteins (specifically amino acids). When cooked at high temperatures this allows them to more easily form nitrosamines, the cancer-causing compound.”
There is increasing evidence that nitrites can offer cardiovascular benefits due to nitric oxide, a potent molecule. Nitric oxide has been found to help dilate blood vessels which improve blood flow.
Although the body can naturally produce nitric oxide, as we age, this ability becomes diminished. This is why consuming foods with nitrites are essential, but more so from vegetable sources rather than processed meat sources.
Although it is difficult to estimate levels of nitrates and nitrites in food, it’s best to stick with leafy greens to get the most intake.
The takeaway here is that, yes, some nitrates are harmful, but as long as you are consuming more vegetables than processed meat, you should be able to reduce your risk of disease and increase blood flow.