Green leafy vegetables are known to be super healthy, just like beetroot and fennel for example. But it all contains nitrate. And there’s something about that. Or not?
The story of nitrate is complicated. First of all, it is not nitrate itself that is a problem, but the nitrosamines that can arise, explains The Nutrition Center on its website. Here’s how: about a quarter of the nitrate from food, meat or drinking water ends up in your saliva. One-fifth of that converts bacteria in your mouth into nitrite. This nitrite can be converted into nitrosamines in combination with proteins. And the latter substance is classified as ‘probably carcinogenic’. On the other hand, nitrate itself has all kinds of health benefits. It is good for heart and vascular health. This reduces the risk of related conditions such as dementia, diabetes and heart disease.
What should we do with this information? To eat nitrates or not? Australian researchers Edith Cowan University (ECU) wanted to find out the opposite health effects once and for all and therefore listed all nitrate research. The conclusion: it depends on where the nitrate comes from. “We get nitrate from three main sources: meat, water and vegetables,” says lead researcher Catherine Bondonno. “Nitrate’s bad reputation dates back to the 1970s when two studies showed that it can form nitrosamines that were found to be highly carcinogenic in lab animals.” But she continues: “No human studies have confirmed the potential dangers, and our clinical and observational studies show that nitrate helps prevent cardiovascular disease when sourced from vegetables.” Time for an overview study. “This review serves to further unravel the effects and to come up with new ways to solve this puzzle, because it’s about time: the discussion has been going on for fifty years,” said the researcher.
Although recent research shows that the source of the nitrate matters, current dietary guidelines date back to the 1970s and do not distinguish between nitrate from meat, vegetables or water. “Nitrate-rich vegetables, unlike meat and water, contain a lot of vitamin C and polyphenols that counteract the formation of the harmful nitrosamines,” the researcher explains.
She emphasizes that more research is therefore necessary so that the guidelines can be updated. “People are probably not listening to the message to eat more nitrate-rich vegetables if they are concerned about a link between nitrate and cancer.”
On the other hand, it is important to exclude health damage if people ingest larger amounts of nitrate. There are now also nitrate supplements on the market. “We need to make sure that nitrate-rich vegetables do not increase the risk of cancer if we consume them in larger quantities,” she explains. “High-dose nitrate supplements are already being used to improve athletic performance and vegetable nitrate extracts are added to processed meats with a ‘healthy label’ suggesting they are good for you.”
Half cup of vegetables
Given the division of experts, it makes sense that people no longer know whether nitrate is good or bad for them, says Bondonno. “They must be thinking: if I can no longer eat salad, so what?” These people can reassure the researcher. “Dark green leafy vegetables, such as spinach and endive, and beetroot are good sources. According to our research, a cup of raw or half a cup of cooked vegetables a day is sufficient for cardiovascular health benefits,” she says. “We know that processed meat is bad for us and we should limit our intake of it, but whether it’s nitrates that are causing the problems or something else, we don’t know.”
She does think that her study makes it clear once again that it is important to research the effects of nitrate, so that the message is clear to people. “The possible link with cancer dates back fifty years. Now is the time to use better research to distinguish between fact and fiction.” And the conclusion is: nitrate is healthy, as long as you get it from vegetables.