Meat is still considered THE iron supplier par excellence. And so everyone who avoids meat is automatically included in the risk group for iron deficiency. But there are many people who eat plenty of meat and sausages and still have an iron deficiency. Iron deficiency is therefore not a problem for vegans, and iron requirements can be met very well with foods containing iron. In the following article, we explain in detail how this can be achieved despite phytic acid, oxalic acid, and the like.
Iron: How to meet your needs
With a vegan diet, sooner or later you will come across the issue of iron. It is usually the dear (non-vegan) fellow human beings who would like to know how to meet the iron requirement with plant foods alone since iron is mainly found in meat and sausages.
But meat and sausage cannot prevent iron deficiency. Because many people who eat meat regularly suffer from iron deficiency.
Conversely, this means: A vegetarian or vegan diet does not automatically lead to iron deficiency, which is why it does not make much sense to fear iron deficiency in a vegan of all people.
Vegan diet and iron deficiency: no connection
Actually, the bare numbers alone show that vegan nutrition and iron deficiency do not necessarily have to be related:
In Germany, no more than 1 percent of the population is vegan. In Germany, however, 1 to 2 percent of men and 5 to 10 percent of women are affected by iron deficiency.
dr Beat Schaub, who founded the so-called iron centers from Switzerland, in which iron deficiency syndrome is treated specifically, says, based on his decades of practice with iron deficiency patients, that it is very likely that every second to third person is affected by iron deficiency.
However, there are not that many vegans and vegetarians.
Again and again, those affected by iron deficiency report that they eat a lot of red meat on the advice of their doctor, but the iron deficiency simply does not improve as a result.
Cover iron requirements with dried fruits and nuts.
dr Schaub says that in his entire professional career, with the exception of two women, he had never seen a patient who had managed to remedy their (massive) iron deficiency with diet alone or to maintain the iron level achieved with iron infusions.
The two women who had made it were not, however, passionate black pudding or steak eaters. They simply ate a lot of nuts and dried fruit – and in this way, they were able to get enough iron. And this is despite the fact that nuts contain phytic acid, which has been so discredited of late, and other inhibitors that are known to greatly impair the absorption of iron and many other minerals.
It is interesting that the chlorogenic acid in coffee and the tannins in tea discussed below are no fewer iron inhibitors than phytic acid. But hardly anyone says a word about coffee as an iron antagonist. Instead, they’re digging into the grains, nuts, and seeds as they’ve finally found a reason in phytic acid to stick with good ol’ meat as a source of iron. But the meat, despite its so well-absorbable iron, is no longer of any use if you reach for coffee all day long.
The absorption-inhibiting effect of phytic acid & co. is obviously overestimated. Otherwise, every whole-food vegan and vegetarian would have to suffer from extreme mineral deficiencies, which is not the case.
Phytic Acid: Really a Villain?
So it’s not worth studying tables that show the phytic acid content of different foods only to avoid those that are particularly high in phytic acid.
Of course, the usual measures are taken to make food more digestible, which usually automatically reduces the phytic acid content, e.g. B. Soaking legumes before cooking (for at least one night). But not every nut has to be sprouted before consumption. You can do it, but you don’t have to.
Phytic acid detoxifies
The metal-binding properties of phytic acid could also give cause for concern since phytic acid can of course not only bind useful minerals but also harmful heavy metals and in this way help the body with detoxification.
It is also known that phytic acid can inhibit the formation of urinary stones.
How can an excess of phytic acid be broken down?
This is also the reason why it is always recommended to combine vitamin C with plant-based iron suppliers. Because vitamin C reverses the mineral-binding effect of phytic acid and thus prevents you from becoming a victim of an excess of phytic acid. (details below)
It is also now known that certain lactic acid bacteria (lactobacteria) can help break down phytic acid. Lactobacteria is members of healthy intestinal flora, which means that phytic acid cannot be broken down optimally if the intestinal flora is disturbed.
In 2005, Italian researchers wrote in Medical Hypotheses that the inhibitory effects of phytic acid from grains, nuts, legumes, and oilseeds can vary greatly depending on the state of the intestinal flora.
According to scientists, the lactobacteria of the intestinal flora is an important source of the enzyme phytase, and phytase breaks down the phytic acid so that it can no longer bind minerals.
Thus, according to the researchers, the regular intake of probiotics could represent an inexpensive and safe method of converting a meal with low bioavailability (e.g. due to high levels of phytic acid) into a meal with high bioavailability.
Finally, it was emphasized that this advantage of probiotics (preparation from lactobacteria) is not limited to vegans or vegetarians, but is also recommended for “normal eaters”.
Anyone who suspects an intestinal flora disorder (dysbiosis) and/or suffers from iron deficiency can take a capsule of a high-quality probiotic with meals and in this way increase their phytase level and lower the phytic acid level.
Oxalic acid: No danger to the iron level
Contrary to some prophecies of doom, oxalic acid does not pose a particular problem for the iron level either. It is also said to bind iron and can thus contribute to iron deficiency, which is why leafy vegetables rich in oxalic acid are not officially recommended as a source of iron.
However, we have already explained here based on a Swiss study from 2008 (green leafy vegetables for iron deficiency) that oxalic acid does not pose a risk to the iron supply either.
It is therefore not the purely plant-based diet including phytic acid and oxalic acid that leads to an iron deficiency. But then what is the cause of iron deficiency?
Iron deficiency: the causes
Iron deficiency can have many causes – depending on age, gender, diet (healthy or unhealthy), and general health.
Iron deficiency due to an unbalanced diet
Iron deficiency can develop – especially in children – as a result of an unbalanced diet. But “one-sided” does not mean meatless here, but rather the fact that food is simply unhealthy and low in iron and vitamin C (too many baked goods, pasta and confectionery, too many soft drinks, too few vegetables, and fruits).
A diet with too much cow’s milk can be the reason for an iron deficiency in small children since the milk itself is very low in iron and at the same time can inhibit iron absorption due to its high calcium and casein content.
Milk is also the reason why it is said in some places that vegetarians are more at risk of iron deficiency than vegans and normal eaters. Because vegetarians often compensate for meat and sausages with increased consumption of dairy products.
Iron deficiency – especially in women – often has completely different causes.
Iron deficiency due to menstruation
Women of childbearing age are often affected by iron deficiency, in most cases because they lose a lot of blood and therefore iron every month during menstruation.
In these women, the iron loss through monthly bleeding is higher than the amount of iron that can be absorbed through the most unhealthy diet.
Iron deficiency from medication
Older people also suffer from iron deficiency again and again. They often eat little and are low in iron. In addition, the absorption of iron is impaired in them due to the widespread chronic gastrointestinal complaints. And last but not least, older people usually take certain medications that belong to the iron inhibitors:
- ASA (acetylsalicylic acid)
- Acid blockers (e.g. omeprazole)
- Antacids (e.g. Talcid, Maaloxan etc.)
- cholesterol-lowering agent
- Medicines for urinary stones etc.
- Iron deficiency due to internal bleeding
Other causes are unnoticed internal bleeding (e.g. due to a stomach ulcer or intestinal disease) or hemorrhoids.
Even in athletes, this factor is said to be an important cause of iron deficiency, since heavy physical exertion often causes internal microbleeds, which are then associated with iron losses.
Iron deficiency due to lack stomach acid
A lack of stomach acid can also lead not only to iron deficiency but also to a mineral deficiency in general, because only with sufficient stomach acid can meals be broken down accordingly, and the minerals later in the intestine also are reabsorbed.
The easiest way to stimulate the formation of stomach acid and other digestive juices is natural bitter herbs, e.g. B. in powder form (e.g. bitter base powder from Sonnentor) or as an alcohol-free herbal elixir.
Although a vegan or vegetarian diet is also listed as a risk factor for iron deficiency on many websites, it has only rarely been proven in studies.
Vegan Diet: No Cause of Iron Deficiency
As early as 1981, a study of Adventists, who mostly eat vegetarian food for religious reasons, showed that the participants had sufficiently high levels of iron and zinc, even though their diet was low in readily available iron and zinc and at the same time rich in phytic acid.
In 2003, researchers in the American Journal of Clinical Nutrition wrote that while vegetarians may have lower levels of zinc and iron in some cases, they do not appear to have any adverse health effects — on the contrary, it is believed that moderately lower iron levels are actually healthier and preferable protect against chronic diseases. Iron supplementation, on the other hand, should be viewed critically.
A year later, the German Vegan Study by the University of Hanover also showed that vegan women in particular have low iron levels, even though they take in more iron with their diet than the German Society for Nutrition recommends. However, only three of the 75 women examined had anemia (iron deficiency anemia).
Iron deficiency is less common in vegans than in meat eaters
If you now look at the frequency of iron deficiency anemia in women in Europe, you come across the following information: One in ten women in Europe suffers from iron deficiency anemia. This, in turn, means that 10 percent of all women suffer from iron deficiency anemia, even though they eat “quite normally”, i.e. also eat meat, sausage, and fish.
In the vegan study, however, there were only three women out of 75, which corresponds to only 4 percent. Vegans, therefore, seem to develop a manifest iron deficiency less frequently than their meat-eating counterparts.
A Japanese study from 2009 confirms that the type of diet does not correlate with iron deficiency, so you cannot tell from diet whether someone is in an iron deficiency risk group or not.
In 2014, Watanabe et al. examined whether a vegan diet can provide people with all the nutrients and vital substances. While the researchers found borderline levels of vitamin B12 when not supplemented (not surprisingly), iron levels were within the normal range.
The scientists emphasized that the test persons practiced a wholesome and healthy vegan diet, which also contained sea vegetables (norialgae) and various mushrooms. Because an unhealthy vegan diet – just like an unhealthy omnivore diet – can lead to nutrient deficiencies and thus to iron deficiency.
Covering the iron requirement is not possible with an unhealthy vegan diet
In February 2016, the Journal of the American Osteopathic Association published an article by Mayo Clinic researchers. They write:
“Now 2 percent of the US population is vegan and many studies have long shown that a plant-based diet has many health benefits. It is very healthy for the cardiovascular system, reduces mortality from certain heart diseases, lowers high blood pressure, blood lipids, and obesity alleviates diabetes symptoms, and reduces the risk of cancer.”
Despite these advantages, however, vegans should also pay attention to a healthy diet, because “vegan” alone is far from healthy. So you can eat biscuits, chips, cakes, rolls, chocolate, crispies, yogurt, etc. all day long and call the whole thing – if they are vegan biscuits, chips, etc. – vegan. Deficiencies are of course pre-programmed here (as with any other unhealthy diet).
An omega-3 fatty acid deficiency can develop, for example, a calcium deficiency, a B12 deficiency, and also an iron deficiency – according to researchers at the Mayo Clinic.
But how can you eat so vegan that you are well supplied with iron? First of all, of course, the iron requirement is of interest:
Iron: The need for children and adults
However, the amounts of iron mentioned do not indicate the actual requirement. This is about one-tenth of the specified amount. However, since only a small percentage of the iron in the diet can be absorbed (5 to 10 percent), you have to consume a multiple of what you actually need in order to get enough iron.
However, the amount absorbed does not always remain the same. It also depends on personal needs. If there is an iron deficiency, the absorption rate can increase to up to 30 percent.
This means that if the body needs more iron, it can also make better use of the iron present in food – even if the food contained little iron.
There are also factors that contribute to an even better absorption rate (vitamin C, probiotics) and there are factors that worsen absorption (phytic acid, polyphenols, calcium), so with this knowledge, you can influence and improve your personal iron absorption very well.
Cover iron requirements for vegan
In order to cover the iron requirement in vegan or with another diet, one always proceeds in the same way (provided, of course, that there is no manifest iron deficiency with anemia that requires a doctor’s visit):
- First of all, you look for those foods that have high and medium iron levels and that you like. Meals are made from these foods.
- To do this, you eat or drink foods that promote iron absorption.
- At the same time, avoid those foods that inhibit iron absorption.
Vegan foods high in iron
Below you will find vegan foods that are good for iron supply (if not stated otherwise, then always per 100 grams):
Please note Nutritional values and thus also the iron values of food can naturally vary and depend on many factors, e.g. B. from the respective variety, the cultivation, and fertilization method, the soil quality, the climate, the country of origin, the harvest time, the storage method, the storage period, etc. The values given by us are therefore only a guide and can also vary in reality – or be exceeded.
Prepared foods artificially fortified with iron
In the supermarket, there are also vegan foods that have been artificially fortified with iron. This includes breakfast cereals (mueslis, cornflakes, crunchy foods, etc.), some drinks, and granola bars.
Such finished products are not recommended. Apart from the fact that they usually contain a lot of sugar, they harbor the risk of an excess of iron. Because if you eat it regularly, you quickly lose track of how much iron you have already consumed. In no time it is too much – especially for children, who have a significantly lower iron requirement than adults.
For example, if a seven-year-old eats an iron-fortified crunchy for breakfast, drinks a glass of iron-fortified juice, and eats an iron-fortified granola bar at school, they’ll have 2.5 times the iron they need in no time. This does not even include all the other foods that it eats and that also provide iron. Therefore, when buying the finished products mentioned, make sure that they are possibly enriched with iron.
However, an excess of iron via foods fortified with iron can now contribute to cardiovascular diseases, arteriosclerosis, cancer, and diabetes. Because the body has no mechanisms available for iron with which it could regulate the iron balance. Too much iron cannot simply be removed from the body again through increased excretion.
Even the Federal Institute for Risk Assessment, therefore, finds that the risks of a possible excess of iron from fortified foods clearly outweigh the risk. Therefore, when buying the finished products mentioned, make sure that they are possibly enriched with iron.
What promotes iron absorption?
However, if you eat healthy and fresh vegan foods, then it is worth considering those factors that can improve iron absorption from the intestine or iron metabolism in general.
In addition to the measures listed above to avoid an excess of phytic acid (e.g. soaking, sprouting, and probiotics), this also includes u. certain amino acids and of course vitamin C.
Certain amino acids promote iron absorption
The amino acids methionine and cysteine can improve iron absorption. Both are e.g. B. contained in high amounts of rice protein, which would be a good dietary supplement in a vegan diet – which is often low in protein.
Onions and garlic promote iron absorption
A 2010 Indian study showed that onions and garlic—whether raw or cooked—can boost iron and zinc absorption from a grain meal.
Fruits promote iron absorption
Fruits contain not only vitamin C, which can improve iron absorption, but also organic acids and fructose, both of which also have a positive effect on iron balance.
Vitamin C promotes iron absorption
The usability of trivalent iron from plant-based foods can be increased very easily simply by eating foods or drinks rich in vitamin C in addition to plant-based foods. Because vitamin C deactivates the phytic acid in grains, nuts, oilseeds, and legumes.
So you cut fresh fruit into the muesli, eat the millet casserole with lots of vegetables, nibble on a red pepper with wholemeal bread and eat pumpkin seeds and nuts with fresh salad, etc.
Incidentally, vitamin C not only promotes iron absorption but also influences the iron metabolism in every nook and cranny – as Australian researchers from the University of Sydney explained as recently as 2014:
Vitamin C not only improves iron absorption in the intestine but also iron uptake into the cell. Vitamin C stimulates the formation of stored iron (ferritin), inhibits the breakdown of stored iron, and reduces iron loss from the cell.
Vitamin C is therefore such a great support for the iron balance that increased consumption of vitamin C alone can remedy some iron deficiencies (without having to increase the amount of iron in the food at the same time).
In one study, Indian children with iron deficiency were given 100 mg of vitamin C with lunch and 100 mg of vitamin C with dinner every day for two months. The children received neither an iron-rich diet nor iron supplements. Meals were vegetarian. Most children could be cured of their iron deficiency by this measure alone.
Vitamin C should ideally be taken directly with meals. But it is also sufficient if it is eaten within one to two hours after the last meal.
It also doesn’t have to be 200 mg per day – as in the study described above. We know that when it comes to iron intake, even half is enough.
What hinders iron absorption?
At the same time, there are foods that inhibit iron absorption and that are best not eaten or drunk with a meal containing iron.
Coffee, cocoa, and tea can inhibit iron absorption
Coffee, cocoa, black and green tea, but also herbal teas, and red wine are typical inhibitors of iron absorption. They inhibit the absorption of iron, in particular, due to their high polyphenol content.
It is true that polyphenols are very healthy because their antioxidant effect protects against almost every disease by helping to reduce the body’s oxidative stress and eliminate free radicals. However, if you have a low iron level, it is better to drink polyphenol-rich drinks several hours apart from a meal containing iron.
Scientists from the ETH Zurich (Technical University) wrote in the British Journal of Nutrition in 1999 that a cup of coffee, black, green, or herbal tea (with approx. 100 – 400 mg polyphenols) are potent iron inhibitors when drunk with a grain meal would. Here are some examples of the research results:
- Black tea inhibited iron absorption from grains by up to 94 percent.
- Peppermint tea did this by up to 84 percent.
- Cocoa by 71 percent
- verbena tea by 59 percent
- Linden blossom tea by 52 percent
- chamomile tea by 42 percent
If you add vitamin C to the tea in the form of lemon juice, the vitamin can partially reverse the inhibiting effect of the polyphenols on iron absorption. 50 mg of vitamin C would be required to reverse the inhibitory effect of 100 mg of polyphenols (e.g. the EGCG in green tea).
However, a 150ml cup can contain up to 150mg of EGCG, which is of course great when it comes to health prevention as EGCG is green tea’s famous anti-cancer compound.
However, if you are aiming for iron, it is better not to drink green tea with food – especially since, conversely, the iron also inhibits the effect of the polyphenols, so ultimately you cannot really benefit from either of them.
Spices can inhibit iron absorption
The matter with the polyphenols is not always clear. For example, although chili contains fewer polyphenols than turmeric, a Thai study showed that chili inhibited iron absorption but not turmeric.
In case of iron deficiency, it is better to season with turmeric and leave the hot pod on the left.
Calcium can inhibit iron absorption
If you add milk to coffee or the drinks mentioned, this in no way reduces their inhibitory effect on iron absorption. On the contrary. Milk is known to be rich in calcium and calcium is considered an iron inhibitor. In addition, calcium not only inhibits the absorption of iron from plant foods (nonheme iron) but also the absorption of iron from meat (heme iron).
These natural iron supplements are recommended
If you suffer from severe iron deficiency or if you cannot raise the iron level with your diet alone, there are various natural iron-containing food supplements to choose from that you can take or integrate into your diet.
The first two of those listed below are over-the-counter iron supplements that provide high, yet well-tolerated doses of iron. The rest are holistic dietary supplements with a relatively high iron content:
- Iron from the curry leaf
- Chelated iron (iron bound to an amino acid, e.g. ferrous bisglycinate)
- Hemp protein 3.5 mg iron in 15 g
- Chlorella 6.3 mg iron in 3.5 g
- Barley grass powder 3.7 mg iron in 10 g
- Moringa 2 – 2.8 mg iron in 10 g
- Parsley leaf powder 2.4 mg iron in 10 g
Please note that the iron content can vary greatly – depending on the manufacturer, year of harvest, region of origin, climate, etc. It is therefore better to ask the retailer/manufacturer in advance about the iron content of the current batch.
When buying curry leaf iron preparations, make sure that they do not contain any unnecessary additives, such as e.g. e.g. maltodextrin, corn syrup powder, and others. While there are worse things, if there are alternatives without these substances, we would rather use them. Very good preparation is, for example, Ferroverde 14 from Nicapur (14 mg iron per capsule plus 40 mg vitamin C.
In a test, curry leaf iron was not only better absorbed than a conventional iron preparation (iron(II) gluconate), it was also much better tolerated. While the subjects from the iron(II) gluconate group suffered from nausea, abdominal pain, and vomiting, the curry leaf subjects felt fine.