Nitrates are known as “Dr. Jekyll and Mr. Hyde” from the world of nutrition.
We’re often told to avoid them in processed meats, but also to look for the plants they’re found in (including beets and spinach). Understandably, this recommendation is confusing.
These are actually produced naturally in our bodies, but simple compounds (made of nitrogen and oxygen) are also found in many of the foods we eat and even the water we drink.
Although most of these nitrates are eliminated through urine, our body absorbs some of them.
Bacteria in both the “deep crypts” of our tongue and in our stomach turn them into nitrites (Nitrates and nitrites are very similar, the difference simply comes down to the number of oxygen atoms they contain).
But in what foods are they found and what impact do they have on our health?
What foods contain nitrates?
We get most of our nitrates from vegetablesexplains Catherine Bondonno, senior nutrition and health researcher at Edith Cowan University in Australia.
“The main source of nitrates in the diet comes from floorswhich represent around 70-80% of our daily intake“says the expert.
Bondonno adds that between a 10% and 15% comes from meat“both natural (nitrates) and those used as preservatives in processed meats.”
And, perhaps surprisingly, drinking water can also contain them: “approximately 1 to 10% of our intake often comes from rainwater channels in agricultural and livestock production”, says.
Leafy vegetables, such as spinach, lettuce and kale, as well as beets and celery, are some of the largest natural sources of nitrates. These natural nitrates are believed to have health benefits.
What nitrates are good for you?
Bondonno says there is substantial evidence showing that plant-based nitrates They improve cardiovascular health and may reduce the risk of stroke.
The high natural nitrate content found in beet juice, for example, has been found to significantly reduce blood pressure in people with high blood pressure.
This may be because the nitrate found in vegetables can be converted to nitric oxide in our body, which dilates blood vessels and, in turn, can lower blood pressure.
But research results on heart health and nitrates are mixed. While there is abundant evidence demonstrating the heart health benefits of consuming a plant-rich diet, such as the Mediterranean diet, some studies have found that nitrates have no specific effect.
For example, a large-scale study looking at the effects of nitrates on heart disease risk found that even the highest intake of plant-based nitrates (about two servings of leafy green vegetables per day) was not associated with a lower risk of heart disease.
And researchers say long-term evidence investigating this specific relationship is lacking.
One explanation for why nitrates in vegetables are good for us, or at least not harmful, could be that vegetables high in nitrates They also contain high amounts of vitamin C and other antioxidants.which have been found to prevent the damaging reaction of nitrates.
Why can some nitrates be bad for you?
Despite the possible health benefits of nitrates found naturally in vegetables, it is widely considered that nitrates and nitrites added to processed meat to prevent bacterial growth they have harmful effects on the body.
It is not necessarily the chemicals themselves that cause health risks, but rather what they become when we consume them and what these converted molecules do in our bodies, specifically, when cancer-causing N-nitroso compounds react with protein fragments left over from our digestion.
According to the Harvard THChan School of Public Health in the United States, “meat processing, such as curing (for example, adding nitrates or nitrites) or smoking, can lead to formation of potentially carcinogenic chemicalssuch as N-nitroso compounds (NOC) and polycyclic aromatic hydrocarbons (PAHs).”
Due to their potentially carcinogenic properties, scientists have repeatedly called on the UK government to ban the use of nitrites in processed meats.
The scientists’ latest push comes from research from Queens University Belfast, which found that mice fed a diet of processed meat containing these chemicals developed 75% more cancerous tumors than those fed pork. without nitrites.
But the argument is not so clear. Some scientists concluded in 2017 that the consumption of nitrates added to meat products at the level to which we are exposed is “little worrying” for our health.
While processed meat is associated with an increased risk of developing colorectal cancer and possibly also stomach cancer, experts point out that these risks are not only related to nitrates and nitrites, but also to the content of salt and saturated fat.
How can we have a healthy diet that contains nitrates?
A significant body of research shows that a diet rich in vegetables and low in processed meat is beneficial for our health.
Bondonno’s recommendation is to focus on incorporating a variety of plant-based foods to our diet, especially leafy greens (spinach, kale, arugula), root vegetables (beets) and other plants rich in nitrates such as celery and radishes.
“These natural sources of nitrates not only provide other essential nutrients but also contribute to overall cardiovascular health,” he says.
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