Should You Avoid These Foods if You Have Anemia?

Most of the advice you see online for people who have anemia involves eating foods rich in iron. But you may also have read or heard that some foods can inhibit your iron absorption and make you more iron deficient. Let’s take a look at some of these claims.

The Science of Foods and Anemia

Years ago, I heard on the news that even though spinach was really rich in iron, it also had an ingredient that could block you from absorbing iron.

Well, that was upsetting. I pictured myself eating a nice juicy steak along with some spinach and feeling even more exhausted after the meal than I had before.

Or maybe I’d take my iron supplement and it would seem to do me no good. Was that because I’d eaten spinach for lunch?

Then I did some research. I found loads of blogs advising me that all sorts of foods could block iron absorption!

And they had links to websites with medical names! It had to be true, right? But scientists have been studying this issue ever since. And it turns out a lot of what I heard just wasn’t the whole story. None of it was completely false. But sometimes getting half the story is worse than getting none at all.

If you’ve been told to self-monitor your anemia, you might want to familiarize yourself with these three potential signs of anemia.

Understanding Iron Absorption Better

Iron absorption is complicated because it depends on many things: what you eat, how your body works, and even the timing of meals. Your body absorbs two kinds of iron from food: heme iron and non-heme iron.

Heme iron comes from animal foods like meat, poultry, and fish. Non-heme iron is found in plant foods like beans, spinach, and grains.

Heme iron is easier for your body to absorb, usually around 15-35%. Non-heme iron is absorbed less efficiently, about 2-20%, and is more affected by other foods you eat at the same time.

This is why some foods can block or boost iron absorption more when you’re relying on plant sources of iron.

Foods and Anemia

So why would a food block your iron absorption, and what can you do about it?

Phytates and Iron Absorption

One important group of compounds that can reduce iron absorption is called phytates (or phytic acid). Phytates are found in whole grains, nuts, seeds, and legumes.

They bind to iron and other minerals and make them harder for your body to absorb. But the effect of phytates on iron absorption can be reduced by cooking methods like soaking, fermenting, or sprouting these foods.

For example, soaking beans overnight before cooking can lower phytate levels and improve iron absorption.

Polyphenols and Iron Absorption

Polyphenols are natural compounds found in many plant foods and drinks, like tea, coffee, wine, and some fruits and vegetables. They can block non-heme iron absorption by binding with it.

Foods that Boost Iron Absorption

The trick is to combine foods that might block iron absorption with foods that boost it. Vitamin C is a good one. You can squeeze a lemon wedge into your iced tea with an iron-rich lunch.

Vitamin C works by turning iron into a form that’s easier for your body to absorb. That’s why adding lemon juice to spinach or drinking orange juice with a meal can help you get more iron from plant-based foods.

If you take iron supplements, taking them with vitamin C or a glass of orange juice can improve how much iron your body absorbs. This is especially useful if you’re vegetarian or vegan and rely more on non-heme iron.

Or you can take a Vitamin C supplement. If you’re looking for one, I like Country Life Vitamin C chewable tablets. They have a better flavor than most brands and not so much of the chalky texture.

A supplement that does inhibit iron absorption

There is one supplement and food item you need to be aware of, for sure: calcium. Calcium does interfere with iron absorption. But there’s a strategy for making it work: you just need to take calcium supplements and iron supplements at different times of the day.

You should also be aware of calcium in food form. For example, the calcium in cheese could make a cheeseburger less helpful for your iron levels than a hamburger without it.

How the Timing of Meals Affects Iron Absorption

When you eat certain foods or drinks can make a big difference. As mentioned earlier, coffee and tea block iron absorption if taken with or right after meals but not if consumed an hour before eating.

Similarly, calcium-rich foods, just like calcium supplements, should be taken at a different time than iron-rich meals or supplements because calcium blocks both heme and non-heme iron absorption.

Spacing out these foods and supplements during the day helps you get the most iron from your diet.

Foods to avoid… or not?

1. Spinach

As I said above, this whole learning journey started with a report that spinach contains oxalic acid, and OA can binds with the iron and keep your body from using it.

It turns out spinach does inhibit iron absorption, just not enough to worry about. And it’s not the OA that’s the problem – it’s the calcium and some other ingredients.

2. Red wine

It’s true that red wine inhibits iron absorption a little bit, at least compared to white wine. But again, it’s not significant enough to worry about:

“Our findings indicate that the inhibitory effect of phenolic compounds in red wine is unlikely to affect iron balance significantly.”

3. Coffee

Sorry to be the bearer of bad news, but coffee really can interfere with iron absorption. But only if you drink it along with or just after a meal:

“No decrease in iron absorption occurred when coffee was consumed 1 h before a meal, but the same degree of inhibition as with simultaneous ingestion was seen when coffee was taken 1 h later.”

So drink coffee in between meals, being sure to leave at least an hour on either side of your meal.

4. Black and green teas

It turns out both herbal and black and green teas can interfere with iron absorption when you’re getting it from plant sources, but they don’t block it from meat.

“Our findings demonstrate that herb teas, as well as black tea, coffee and cocoa can be potent inhibitors of Fe absorption. This property should be considered when giving dietary advice in relation to Fe nutrition.”

But again, the trick is to drink tea in between meals:

“Recommendations with respect to tea consumption (when in a critical group) include: consume tea between meals instead of during the meal; simultaneously consume ascorbic acid and/or meat, fish and poultry.”

5. Soy proteins

Soy protein isolate definitely blocks iron absorption:

“The soy products tested in this study have a pronounced inhibitory effect on the absorption of nonheme iron.”

Soybeans in general also inhibit it:

“We conclude that there are two major inhibitors of iron absorption in soybean-protein isolates, phytic acid and a protein-related moiety contained in the conglycinin (7S) fraction.”

It’s not clear if other forms of soy also block iron. One study seemed to find that some forms of it may actually help with iron absorption, but they were unable to reach any conclusions because some of the data didn’t make any sense.