Nitrates, nitrites, oh my!
You might've heard in some contexts, nitrates can be really good for you.
And then in other contexts, you’ve heard that nitrates are bad for you.
The reality is both of those things are true. Listen to this episode if you want to know the difference!
Time Stamps
00:00 Introduction to Dietary Nitrates
02:26 The Benefits of Nitric Oxide
03:49 Nitrates and Exercise Performance
06:43 The Formation of Nitrosamines and Cancer Risk
07:00 The Impact of Mouthwash on Nitric Oxide Levels
08:20 Conclusion and Call to Action
Transcript
Jono (00:01.134)
Welcome back to the Bite Me Nutrition podcast. Today we're going to be talking about dietary nitrates, how they can impact your health, where you can find them in foods, and just a few important nuances that we need to understand when we're talking about nitrates. Because you might've heard in some contexts, nitrates can be really good for you. And then in other contexts, you hear that nitrates are bad for you. And the reality is both of those things are true. But by the end of today's podcast, you'll understand why and you'll understand the different scenarios. There might be a little bit of chemistry that I need to go through. It won't be too heavy because I mean, I'm not very good at chemistry anyway. So we're both on equal footing, but it's just helpful to understand, I guess, the different end products that can occur and the different ways that they can impact upon your health. So firstly, you're going to find nitrates predominantly in two sources, fruits and vegetables and cured or processed meats. So nitrates and nitrites are very potent. Curing and preservatives. So potent at curing meats and they're really good preservatives. They help with the flavor as well, but they largely help limit the development of bacteria and things and keep that food safe. So that's one source, one pretty high source of dietary nitrates and nitrites. And then on the other end of the spectrum, we've got fruits and vegetables, which can also be very high, specifically things like beetroot is hugely probably the most popular one. And then celery, lettuce, spinach, bok choy, carrot, these things are really rich sources of dietary nitrates as well. Now, you've probably heard different things about processed meats versus fruits and vegetables in terms of health. And that's due to the different pathways, which nitrates can go down in terms of, you know, chemical, or the different compounds that they can create dependent on a few different things. So there's two pathways nitrate can go. Can go down, nitrate can be can turn into nitrate, nitrite, sorry, which can be turned into nitric oxide or NO. On the other side of the coin, we have nitrate becoming nitrite and then forming something, a few different compounds called nitrosamines. And there's a few reasons why nitrate will end up as nitric oxide versus nitrosamines, which I'll go through in a second. In terms of nitric oxide, though the reason why,
Jono (02:26.862)
that can be quite good for our health. In normal amounts like anything, you can reach toxicity. And like most things in the diet, it's pretty unlikely you're gonna reach toxicity. Well, I say unlikely, it's virtually impossible to reach it from a normal diet. So it's not something that you have to stress about at all. But nitric oxide is a really potent vasodilator. And what that means is it helps dilate or relax our blood vessels, which decreases your blood pressure. Right there if the blood vessel is relaxed, it's a little bit bigger, it's a little bit more elastic, your heart doesn't have to pump as hard or work as hard to push blood through the system. We know that, you know, decreasing your blood pressure by like five points can significantly reduce your risk of cardiovascular disease overall. So anything in your diet that's going to help potentially reduce your blood pressure is really great. Now, obviously, blood pressure and cardiovascular disease is complex, there's a lot of other factors that play, you know, like cholesterol and the plaque buildup and all of that. So still other things that we want to be mindful of, sodium, your blood volume, et cetera. But if we can also be consuming something in our diet that decreases our blood pressure through this, like a basal dilation, this relaxation of the blood vessels, then heck yeah, right? That's, I think really important. That same mechanism of action is also why nitrates have been researched pretty heavily for exercise performance, right? Because an increased blood flow, means increased oxygen delivery to the muscles, right? Which is fantastic for performance. It also potentially means an increased removal of waste products again from the muscles, which can help elevate the intensity of that performance and help you to sustain that intensity for longer. So both great things. It's why a diet high in nitrates through fruits and vegetables is a really good idea for well, health in general, but extra good if you're looking for some. Bonus points when it comes to performance. And it's also why you can see things like beetroot shots being promoted pretty heavily when it comes to endurance exercise. And I do, I'm not saying that's a bad thing. I do think they are like me. I'm the only one. The evidence suggests that those are beneficial supplements for longer form or endurance based exercise. Unfortunately, we do need to be careful because not all beetroot shots are created equal. There was a study that actually checked the nitrate content of a variety of different beetroot shots and.
Jono (04:46.078)
There's a whole heap of difference, unfortunately, but anyway, that's a topic for another time. So the other end of the, what am I saying? The other pathway when it comes to nitrates then is the pathway that ends in nitrosamines. Now, the reason why a nitrate might begin its life as a nitrate and end up as a nitrosamine is due to probably three main things. The first is it's in a food that also contains protein. It's in a food that's low in vitamin C and other antioxidants. And it's going to be hit by high heat during cooking process because nitrates plus protein without antioxidants nearby plus high heat significantly increases the formation of these nitrosamines. So for those of you who are, if you like following fruits and vegetables, very low in protein. Fruits and vegetables are very high in antioxidants. And we pretty rarely prepare these with high, high heats. Like, yeah, sure, you might barbecue them sometimes, but most of the time where we're roasting at a lower temperature or we're steaming or often, you know, we're eating them raw. And so for that reason, these high nitrate fruits and vegetables don't form nitrosamines because the lack of protein, the low vitamin, the high vitamin C and antioxidant compound content, and the kind of low heat that they usually come in contact with their nitrates typically end up as nitric oxide, which like I said, is actually quite valuable for our health due to that, you know, the vasodilation. So that is why we see this difference between processed meats and fruits and vegetables, even though they're both high in nitrates, they have very different impacts on our health because these nitrosamines that the processed meats typically can, or not contain, but typically cause the formation of, those are linked with the development of a number of different cancers. And so those are... ideal to limit, which is why we still see that recommendation of keeping processed meats to preferably under 50 grams a day or less if you can, and why we see recommendations of trying to eat over seven serves of fruits and vegetables every day.
Jono (07:00.046)
one last, this is kind of an aside. So hopefully that's made sense. Hopefully you're with me in terms of, I need to have some nitrates. I need to be getting most of those from fruits and vegetables and I need to not rely on cured meats as a form of nitrates or nitrites. But if you're someone who's been struggling with hypertension, sorry, high blood pressure, or you have a family history of high blood pressure, there is a little bit of research showing that regular, like so habitual mouthwash usage, like a couple of times a day can actually, lower our nitric oxide levels and therefore increase our blood pressure slightly. And this is due to the fact that bacteria in our mouth, in our saliva in particular, are responsible for one of the steps of converting nitrate to nitrite and nitrite to nitric oxide. So if we're regularly using mouthwash, we're regularly kind of wiping or lowering that bacterial population and they're having a, they're unable to form as much nit... nitric oxide. So if you're otherwise healthy, it's not something that I would stress about. But if that is an area of your health that is a particular concern to you, I would like chat to your dentist about it as well. I'm not a dentist. I don't know much about teeth, but maybe check with them to see how infrequently can I use mouthwash and still be okay. So hopefully you didn't get scared off by the chemistry. I like saying words like nitrosamine makes me feel smart. If you did find this beneficial, I would love, love, love. Please put it in your story. I love seeing it out there. Obviously I want more people to listen to the podcast to validate me as a human being. And so if you could help that happen by sharing it, I would love you forever. Alternatively, if you haven't subscribed, subscribe. If you haven't left the review, do that and I will see you next time.
Episode Links & References
- Inorganic nitrite and nitrate: evidence to support consideration as dietary nutrients
- Dietary Nitrates, Nitrites, and Nitrosamines Intake and the Risk of Gastric Cancer: A Meta-Analysis
- Acute blood pressure lowering, vasoprotective, and antiplatelet properties of dietary nitrate via bioconversion to nitrite
- Dietary Nitrate and Nitric Oxide Metabolism: Mouth, Circulation, Skeletal Muscle, and Exercise Performance
- Dietary Nitrate and Nitric Oxide Metabolism: Mouth, Circulation, Skeletal Muscle, and Exercise Performance
- Do Changes in Oral Microbiota Correlate With Plasma Nitrite Response? A Systematic Review