Podcast Episode 92 Transcript – Increasing Iron Levels Through Diet



Hello and welcome to the Ideal Nutrition Podcast. My name is Aidan Muir, and I’m here with my co-host Leah Higl, and this is episode 92, where we are going to be talking about how to increase iron levels through diet. And that is a topic that has a lot of relevance to both of us, obviously to Leah because of plant-based diet. Seems- 

Yeah, a little bit more. But it’s something that I care about a fair bit too. Just because iron deficiency is so common, and addressing it can be such, I wouldn’t an easy win, but a impactful win. It’s something that we can clearly measure and we can see how much we need to change things by, and we can have an action plan, address it, and people will often feel better when we address it, and maybe their performance improves as well. According to some data from The Lancet, iron efficiency anemia affects more than 15% of the world’s population. I’m quoting my source that it was The Lancet just because there’s so many different estimates, and it depends on where you look, what numbers you come back at. I’ve seen estimates as high as 30% in certain regions, but obviously the data is skewed by a few factors such as age, gender, socioeconomic status, activity levels, and a bunch of other things. So there’s going to be certain populations or groups of people who are way more at risk, and certain groups that are way less at risk of iron deficiency.


Adding a little bit of context around iron needs and iron deficiency, let’s talk about recommended daily intakes. So the recommended daily intake for men or non-menstruating people is eight milligrams per day. But then if we look at people who do menstruate, so this is usually women between the ages of 18 and 50, that then goes up to 18 milligrams per day. So those requirements come from the loss of iron through menstrual blood, and that’s why the requirements are higher within that particular group. And then we have pregnant people who have even higher needs, and that’s 27 milligrams per day is their recommended daily intake.

So again, goes up substantially when someone is pregnant. From a plant-based perspective, because that is the context that I tend to work in personally, for vegans and vegetarians, anyone who is getting most of their iron, if not all of it, from plant-based sources, the RDI then has to be times by 1.8, just to make up for the differences in absorption rates from plant versus animal proteins. So this could take the 18 milligrams per day for people who are menstruating and make their requirements literally 32 milligrams per day. And when we start talking about food and the amount of iron in food, you’ll start to see why that is quite high.


So going through some other factors that could make your needs a little bit different, using that ages 18 to 50 RDI of 18 milligrams, which assumes menstruation, obviously that can be variable based on how light or heavy the bleed is. A heavier bleed would have higher needs, a lighter bleed would have lower needs. It’s obviously hard for people to quantify this with RDIs, they just use averages. It assumes a combined intake of heme and non-heme iron as well. But as Leah said, you were talking about how people are plant based, it would be higher. Vice versa if somebody was solely animal based, arguably it would be lower. Other things can impact it, like exercises such as running can increase needs. This is for a variety of reasons, like we were talking about this a bit off air, as to which aspect contributes the most, and it’s hard to say, but one aspect is maybe increased sweat losses.

But the other one, which is why I specifically focused on running, is the impact of running and how that increases iron needs. Whether that’s through the breakdown of red blood cells or whatever it is, we know that there is a thing called athletic anemia, which is just athletes are more likely to get it, and other things can also lower your absorption too. So there’s a bunch of factors that can change your needs. Personally, I like to use the RDI to add context since without that RDI, the amounts of iron in food don’t really make sense. If we say that X food has three milligrams of iron, unless you have some form of number that you’re aiming for, that means nothing. So I like the RDI to add context, but I trust everyone listening to this to use a bit of common sense and understand that your own personal needs won’t be exactly these numbers. These numbers are just here to add context for this next section where we’re talking about how much iron is in different foods.


Yeah, so let’s add more context around the iron amounts that we do see in common foods. So the first one we’ll talk about is red meat, which is pretty commonly cited as a pretty rich iron source. So for 100 grams of red meat, there is around 2.5 milligrams of iron. Context to that, if we’re aiming for eight milligrams as a non menstruating person, as a man, 2.5 is quite a high percentage of that eight milligram RDI. But if you are someone who has high needs because menstruation, because there are other factors, maybe an athlete, and say you’re aiming for 18 milligrams per day, then it becomes a much smaller percentage of those needs. So that’s why that context is particularly important. And even still, 200 grams of red meat is still only five milligrams per day. So in the context of someone who does have higher needs, it’s still a relatively moderate amount, even though it’s one of the richest sources of iron in someone’s diet, usually.

Talking about other meats so other meats and fish still contain iron, but it is quite a significant amount less than red meat. So 100 grams of chicken breast contains just one milligram of iron. So less than 50% of what red meat contains going onto some plant-based sources. So 100 grams of spinach, which by the way is quite a bit of spinach if you actually weigh out 100 grams of spinach, contains 2.7 milligrams of iron. So I’m sure we’ll talk about this a little bit, but even just comparing 100 grams of red meat to 100 grams of spinach, I know I’ve seen posts on Instagram being like spinach contains more iron than red meat, but if we think about physically consuming 100 grams of spinach, that’s a lot of volume compared to 100 grams of red meat. So the logistics there are a little bit skewed, but also something to mention is that because it’s a plant-based source, spinach does have a lower absorption rate than something like red meat, which definitely comes into play.

And spinach itself is actually really high in oxalates, which does inhibit iron absorption quite significantly. And it’s even higher in these anti-nutrients, these oxalates, than other greens. So even though it contains a fair bit of iron, the absorption from spinach is actually really quite poor often. So we’ll get into that a little bit later. Looking at some other plant-based sources, so 100 grams of cooked lentils contains 3.3 milligrams of iron. But again, the absorption from this whilst better than spinach, not quite as good as from red meat. And then I guess an interesting point to note would be around liver and other organ meats, they are exceptionally iron rich. So if you are having 100 grams of liver, that’s 6.5 milligrams of iron, which is quite a lot from 100 grams of any kind of food. But how many people are actually eating these kinds of organ meats? Probably not many.


Yeah, I think it’s an interesting thing to be aware of. But I’m going to drive this point home further by using an example, and also adding a calorie deficit into the example as well, because oftentimes we will see clients trying to do multiple things at once, and it could be including a calorie deficit while also trying to increase iron needs. So using an example, I personally maintain my body weight on around 3000 calories. So I’m just going to use myself as an example. My iron needs are around eight milligrams. That’s just the RDI, but I don’t have much reason to think my needs are exceptionally different to that. Let’s compare that to a woman who would be smaller than myself, but still wanting to also lose weight as well, going into a calorie deficit, and maybe let’s say their maintenance calories are 2000 calories, and they go into a deficit and they choose to eat 1,500 calories in this example, and their needs would be 18 milligrams.

So suddenly I have doubled the calorie budget and half the needs because they’ve got to get 18, I’ve only got to get eight, I get 3000 calories. They only get 1,500. You can see with an example like that how iron deficiency can become very prevalent very quickly. Let’s use the steak example. 100 grams of steak or red meat is that 2.5 milligrams of iron. I probably would have a larger steak, let’s call it 200 at least. So let’s go 200, that’s five out of my eight. I go and have some leafy green vegetables and other stuff alongside that. I hit my eight very, very easily, and I have a large calorie budget to do. So use that same analogy for that same woman. Let’s say she eats the exact same 200 gram steak. She would therefore have a larger portion of her total calorie budget taken up by this while eating the same amount, but then it’s still only five out of the 18.

She could then do what I do and then have some leafy green vegetables and stuff like that. And maybe she gets to a similar eight, and she’s still under half of the RDI, which it’s hard to address it that way. And the biggest reason why I use that example as a very specific example is because without this context, you can see how an iron deficiency can be present for a long period of time. There are a lot of people I come across who get the diagnosis, they don’t want supplementation and they want to solve it through food. And I’m a food first kind of person, but it’s hard to solve it through food without understanding the numbers, without understanding this is what I actually need to do if solving it through food.

It’s trying to solve something while going in blind, and without context you could look at it and be like, red meat’s high in iron, I’ll have red meat twice a week. I was previously having it less than once a week on average. This might solve it. But based on the numbers I just laid out, if you took that approach and then didn’t change much else, you would expect to be iron deficient in 12 months time if you did that for 12 months straight. Adding this context just gives a bit of insight being like, okay, if we’re going to choose to pursue this route, this is what we have to do.


Yeah, absolutely. And then even bringing more into discussion like the heme iron versus non-heme iron stuff. So I’ve already discussed this a little bit obviously, but just covering our bases. So heme iron is found in animal foods, and then non-heme iron is mostly found in your plant-based foods. Heme is a lot more bioavailable and the absorption rate is really quite good. On the other hand, the absorption of non-heme iron can be significantly reduced by a lot of other dietary factors including calcium intake, phytates, and oxalates. So those are found in pretty much all your plant-based foods. So fruit, veg, grain, seeds, nuts, legumes, et cetera. Tannins as well, so tannins are found in tea and coffee, and then also zinc can be a competing factor as well that can reduce the absorption of non-heme iron quite significantly. So if you are getting most of your iron from plant-based sources, you will need that overall higher intake of iron.

So that’s why that RDI is 1.8 times the amount, so almost two times the amount of iron needs. But you can also do things to just generally increase the absorption of that non-heme iron. So I would still always recommend getting generally more through food, but also adding on strategies like taking any calcium and zinc supplements away from iron rich foods so you don’t have the competing absorption. Pair sources of iron with sources of vitamin C, so fruit and veg, and that will increase the absorption rate and even counteracts the… So if you’re having, say a calcium and iron rich meal, just adding vitamin C can counteract the issues with absorption that calcium poses quite significantly. And so the vitamin C thing is a big one.

You can also soak and sprout your legumes and greens and that can increase the bioavailability of that non-heme iron. And a big one is keeping your tea and coffee away from meals as well. So if you are plant-based you’re going to have high iron requirements, but you do need to have usually more of a focus on these other strategies to make sure your absorption of the iron is decent, at least. From the perspective of addressing deficiency through food on a plant-based diet, because of the non-heme versus heme stuff, I would rarely if ever recommend just addressing it through diet, because you can see here, not only are your requirements so much higher, but you’ve got all these other things to think about. So that is absolutely something you would want to consider.


And that’s also a perspective that I just share in general. I am usually a food first person, but with iron, I’m pretty quick to go to supplements or infusions. Because if anybody has one, has an iron deficiency, to address it, we usually have to make pretty large changes. And if somebody’s plant-based or not, in a plant-based situation, I’m more likely to do it. But if somebody’s not plant-based, there’s still going to be a relatively large change. And when I say pretty quick, it’s, okay, I will, particularly if the person wants to go down that route, I would usually encourage trying it for a certain period of time, call it three months or whatever. And if there’s not a significant improvement in that time, I’d very much be looking at supplements, because it can address the problem relatively quickly. Should we talk about what supplements we’d recommend if we went down that route?


Yeah, let’s do that. So in terms of supplementation for rectifying deficiency, I would often recommend your higher dose ones. So in Australia that’s going to be your Ferro-Grad C, which is definitely a good one. And then the other one I tend to recommend being brand specific would be. Maltofer iron, and that one specifically tends to not cause as much constipation, which is the biggest reason why I think a lot of people don’t go down the supplementation route for rectifying deficiency is because Ferro-Grad C and other higher dose iron supplements are notorious for causing constipation. And that’s something that if you’re supplementing for a few months, that can be a pretty big turnoff to that kind of intervention.


Yeah, I think so. And as we were speaking about off hours, something I’m pretty passionate about is there’s a lot of people who take supplements that they don’t know works or is doing anything. If we have a diagnosed iron efficiency, it’s something where we know supplementing is going to help. I have had some clients here and there be like, oh, I addressed it and I don’t feel any different, but they’re the outliers in a way.

Most people feel better, their performance will be better. And even if you didn’t, it’s like, well, we should address this anyway, just on the off chance it does something. But it comes with this downside. It comes with a potential risk of constipation and stuff like that. But the way I view it is, it’s like we still try to address it and then look at those symptoms from another perspective, being like maybe we start implementing some nutrition strategies to help with constipation.

That’s a whole separate podcast, but we literally have a podcast on that, which I would be looking at in this case. And there are other strategies like lower dose supplementation, some is always better than none. It’s not going to be the optimal strategy, but it’s better than nothing. And another thing that I’m cautious saying this, but the research shows very clearly that supplementing every second day with iron supplements leads to slightly higher blood levels than doing it every day. So theoretically to optimize things, you should do it every second day.

There’s a lot of reasons for that, there’s a lot of theoretical reasons, but all that really matters is that it works. The reason why I was cautious saying that, there’s two reasons. One, which wasn’t the original reason why I was cautious, but it’s that it’s hard to remember to do something every second day. It’s easier to do something every day. So even though I have this knowledge, I don’t actually recommend this to many people. The reason why I was cautious, though, is because I’m talking about the symptom mitigation. I think, whether I’m right or wrong, I think it makes logical sense that if you did it every second day, you’d be less likely to get symptoms than if you did it every day.

The research hasn’t shown that. The research has shown no difference in symptoms, right?

So I’m just using some logic and being like, I think the research might be, I don’t want to say wrong, but I think there’s a chance that the research hasn’t found stuff due to sample sizes, et cetera. But I am also saying what the research says because there’s a higher chance that I’m wrong, and it’s no difference. So thought I’d put that out there.


And I think for most people when they’re taking supplements, they’re probably likely to forget enough for it to almost be like every second day, and just working with clients, that’s probably what’s happening sometimes in just the real world almost. But something else to consider would be iron infusions. I’m such a huge advocate for iron infusions because I think mucking around with supplements for a long time, it could just be a less efficient way to solve the problem. Although I do obviously realize that with an iron infusion, there’s typically a higher direct out of pocket expense. But it is something that I’m totally all for.


Awesome. This has been episode 92 of the Ideal Nutrition Podcast. As always, if you could please leave a rating and review, that would be greatly appreciated.