- What Is Iron?
- Heme iron vs non-Heme iron
- Other factors that affect Iron absorption rates
- Best vegan sources of iron
- But how much iron do vegans actually need?
- Factors that can change the daily iron requirement
- Iron Deficiencies vs Excess
- Conclusion on iron
What Is Iron?
Iron is an essential mineral that is crucial to healthy blood production and oxygen transport in the human body
It can be stored by humans but not specifically created by us which is why we have to get our iron nutritionally through food
70% of iron is found in the red blood cells (hemoglobin)
And also found in muscle cells (myoglobin)
About 25% of iron is stored in ferritin (a protein that stores iron in the tissues)
Iron is the central atom of the heme group and without iron in hemoglobin oxygen would have nothing to bind to.
And to understand the importance of hemoglobin, you simply have to realize that without it oxygen would not be able to travel throughout our body for everything else to run effectively
Hemoglobin is a red blood cell that enables the transfer of oxygen from the lungs to all the other tissues in your body, and to realize the importance of it. You simply have to understand that without it, our other organs can not effectively do their necessary tasks.
Hemoglobin is the mode of transport for the oxygen and dependant on how healthy and stable your iron supply is will determine whether oxygen travels around your body in a Porsche or on a bicycle with broken pedals.
What role does iron play in the body?
Iron is at the heart of hemoglobin, and an efficient iron supply is vital to healthy hemoglobin functions
Because all our muscles and organs including the brain require oxygen to continue working iron ends up contributing to the healthy functioning of all our primary internal functions
Efficient iron supply and healthy hemoglobin development allows for the smooth running of the brain and all neurological functions, contributes to the metabolization of muscles and also the growth of healthy connective tissue
The importance of a stable and balanced iron supply should not be overlooked
Benefits of iron
- Healthy cellular functions.1.
- Supports a healthy immune system.2,3.
- Transport oxygen around the body in your blood.4.
- Brain function.5,6.
- Serotonin production.7.
- It can help to prevent anemia.8.
- Mood regulation.9.
- Can help to regulate energy levels
Difference between iron types
When we discuss iron some may wonder about the difference between the iron in the gym and the iron in our food
It is the same chemical element that you see on the periodic table Fe, but the main difference is what the iron is bound to atomically.
The iron found in our body and our food is usually bound to organic complexes and proteins forming either ferrous iron Fe2+ or ferric forms of iron Fe3+
Iron, bound to proteins, is 10-15 times more absorbable than just the chemical element on its own.
There are two forms of dietary iron that can confuse those trying to get a grip on the best nutritional approach to this mineral.
Heme iron (found in meat), and non-heme iron (found in plants).
The comparison between the 2 leads to the infamous debate, which iron source is best, animal sources or plant sources?
To get a better understanding of the differences between the two, we will compare each one based on a few key factors
Heme iron vs non-Heme iron
Heme iron found in meat has a generally higher absorption rate than non-heme iron from plants, which is a significant factor as to why so many people will discount plant-based iron. Still, it’s important to remember that higher rates of iron absorption do not necessarily equate to a healthier food.
Long term side effects of heme iron
Various studies have shown that a high intake of heme iron is linked to a multitude of bodily issues and diseases. Not surprisingly, studies have also shown that lowering the amount of heme iron in the diet has the potential to reduce the risk of these diseases.
Below are a few important studies showcasing the effects and results of high and low heme iron consumption.
- Metabolic syndrome lowered by decreasing heme iron
- 27% increase in coronary heart disease for every 1mg of heme iron consumed daily
- Heme iron significantly increased risk of type 2 diabetes whereas supplemental and non-heme iron did not
- 16% increase in type 2 diabetes for every 1mg of heme iron consumed
- 12% increase in cancer for every 1 mg of heme iron consumed
Although meat contains both heme and non-heme iron at about 40-45% to 50-55%, respectively, it is the heme iron that is the differentiator between animal and plant sources of iron.
A question we pose for those on both sides of the diet spectrum is: If studies show vegans and vegetarians are not at any higher risk of iron deficiency when eating a balanced diet and that a plant-based diet has enough iron to hit your RDA safely, Is the difference in absorption between meat and plant-based sources of iron worth the potential issues that can come from heme iron?
Other factors that affect Iron absorption rates
Nutritional factors that affect absorption
Dependant on what nutrients iron you combine with iron, you can either increase or decrease absorption, and knowing which is key to getting the most out of iron on a vegan diet
Factors that can increase iron absorption
- Foods high in ascorbic acid (Vitamin C).1.2
- Broccoli, spinach, green and red peppers, tomatoes and sweet potatoes
- Foods high in beta-carotene and Vitamin A. 3.
- Carrots, sweet potatoes, butternut squash, cantaloupe
If I cook my food in a cast iron pot, will I absorb more iron?
Surprising to many, research shows that you will take in more iron by cooking in this manner, but this is evidently not the most optimal approach to regulate your iron levels.
Factors that can decrease iron absorption
Foods high in phytates/phytic acid or oxalates/oxalic acid
In high phytate meals like rice and beans adding a high vitamin C food source like spinach can help to counteract the effects of the phytates and help balance out absorption.
Foods that contain phytates include:
- Beans, grains, nuts, and seeds
- Foods high in calcium/dairy. 1,2.
- Milk, cheese (which vegans will already be avoiding)
- Foods fortified with calcium, cabbage, soybeans
Foods/drinks containing polyphenols
Studies show that polyphenols affect heme iron absorption. Research completed on grape seed extract also showed a lower absorption of non-heme iron which can lead one to conclude that heme and non-heme iron absorption are both affected by polyphenols.
Further study is still needed to see whether heme or non-heme is affected more than the other when interacting with polyphenols
Foods that contain polyphenols include:
- black & green tea
- red wine
- soy, cloves
- dark chocolate
Iron and food combining
Knowing what helps and hinders iron absorption is key to optimal food, combining and maintaining a healthy balanced diet for the long term.
Timing and food combining are essential for optimal iron absorption. The key thing to remember is that our bodies try to maintain a tight balance when it comes to iron levels.
This balance is in essence automatically done for you when eating a balanced plant-based whole food diet since the variety of nutrients, from vitamin C to vitamin A (that work to enhance iron absorption) and phytates (that work to regulate iron intake) work in synergy
To absorb the most iron in meals, combine your iron source with foods high in vitamin A and C, such as
- bell peppers
- leafy greens
- citrus fruits
Try to keep foods high in phytates, oxalates, and polyphenols to a minimal amount when eating foods high in iron
But don’t neglect these foods
Just move your high iron meal to a different time of day to your meals that contain nutrients that prevent iron absorption so you can get the best of both worlds.
Best vegan sources of iron
A few vegan food sources high in iron are:
- Dried peaches (per 100g)
- 4.1mg of iron
- Quinoa (per 100g)
- 1.5mg iron 8% RDA
- White beans (per 100g)
- 3.7mg iron 21% RDA
- Cashew nuts (per 100g)
- 6mg of iron 33% RDA
- Squash and Pumpkin seeds (per 100g)
- 9mg iron 49% RDA
- Spinach (per 100g)
- 4mg of iron 20% of RDA
Data from www.myfooddata.com
There is a multitude of plant-based foods that contain a significant amount of iron alongside other beneficial nutrients that provide overall balance to your diet. For our top 15 vegan foods high in iron backed with nutrition data and food suggestions, click here.
Fortified foods can be a great alternative to fruits and vegetables for vegans looking for a boost of iron on an already balanced diet. Fortified cereals tend to provide the most iron per serving, but since a lot of your iron will usually come from your everyday vegetables, grains, and seeds, you won’t need a large helping to help you hit your recommended daily amount. Below are some fortified foods high in iron and their stats that you can potentially add to your diet
- Fortified instant oats (55g serving)
- 13.7mg iron 76% RDA
- Soy milk (per cup)
- 1.1mg iron 6% RDA
- Fortified Rice Puffs (per cup)
- 4.4mg iron 25% RDA
- Fortified tofu (per cup)
- 3.6mg iron 20% RDA
A healthy plant-based iron supplement can be a great addition to an unbalanced diet that can help to make up for any nutritional inefficiencies and to ensure the recommended daily amount of iron is met.
It is always best to get as much iron as you can from a balanced plant-based diet and not to rely on supplements as your sole source of nutrients
For those looking to add a bit of an iron boost, our favorite vegan iron supplements can help you pick one that works best for your current situation (link to commercial calcium article)
An alternative to an iron focussed supplement is a plant-based multivitamin that contains a much smaller dose of iron as well as a host of other essential nutrients needed on the vegan diet such as zinc, calcium, b12 and vitamin d to name a few. (link to commercial multivitamin article)
This will mainly be for women to replace iron lost through menstruation.
Multivitamins for men don’t usually contain iron since the iron needs of men are much lower than women. Most men if eating a balanced diet can achieve their iron needs with ease.
But how much iron do vegans actually need?
As we go through our everyday human processes such as moving, exercising, sweating, urination, bleeding, we lose iron
This needs to be replenished daily to allow all our necessary functions to run effectively and to avoid deficiency
The recommended daily amounts for iron tend to vary based on age and gender, but the average requirement for an adult woman between 19-50 is 18mg and for an adult man of the same age is 8mg.
Factors that can change the daily iron requirement
Age & Sex
Higher demand for iron in younger age with iron requirements being more in the first 7-12 months
Fluctuates throughout childhood with around a 7-10mg daily demand
Puberty for both men and women causes iron demands to rise to 11mg for men and 15mg for women
11mg ends up being the peak for men, and throughout the rest of life into old age the iron requirements for men stabilize at 8mg
Women, on the other hand, require a higher iron requirement into adult age due to menstruation with an average RDA of 18mg, which increases with pregnancy to 27mg per day.
As women reach menopause iron requirements for the body lower to match the demands of men at 8mg per day.
Iron and athletes – does exercise affect how much we need?
Iron is especially important for athletes since its crucial to getting an efficient oxygen supply circulated around your body for you to perform at your best
Athletes in general and those who do regular exercise will likely need a slightly higher intake than those who live sedentary lifestyles
This is due to the amount of iron that gets lost through sweat and urinary excretion
Males tend to lose more sweat than women while exercising which can lead to slightly higher iron loss when performing.
Iron loss is more of a concern for women since they overall lose more through a combination of sweat, menstruation, and excretion
The main point to take away is to ensure you maintain a sufficient iron supply. The more you train, the higher your iron requirement tends to be.
A low iron supply may hinder your exercise output due to inefficient oxygen transport so balancing your diet through healthy iron foods and in some cases supplementation (especially for women) may be the best solution
Always consult your doctor to make sure you are on the right track to balancing out your iron levels
Iron Deficiencies vs Excess
And women due to menstruation and pregnancy
People the most at risk of iron deficiency are those on extremely low-calorie diets, those with very unbalanced diets or those with digestive issues that make it hard to absorb nutrients
Symptoms of deficiency
Iron deficiency doesn’t have to mean at the extreme levels but just lower than advised for your body to maintain a healthy state. If any of these symptoms are noticed consult your doctor
- Short breath
- Pale or dull skin
- Weak or brittle nails
- Chest pain
- Most serious being anemia
Can you have too much iron?
The tolerable upper intake limit of iron for adults is 45mg
Iron, although extremely important, needs a delicate balance to play its role in the best way possible. Although those on a healthy balanced diet rarely have iron issues its important to understand the balance since too little can cause a deficiency and too much can cause an excess which can sometimes lead to or be caused by a condition known as Hemochromatosis
Hemochromatosis is a condition that causes your body to absorb more iron than necessary, and with no way to get rid of the excess, the iron is then stored in your organs and joints leading to issues with your liver, heart, skin and overall energy levels.
Excess iron in most individuals is caused by the inefficient use of supplements, suboptimal caloric intake or digestive system issues
Some symptoms of excess iron:
- Liver disease
- Abdominal pain
- Pain in the joints
- Heart issues
Consult your doctor if any issues are noticed
Conclusion on iron
Balance with iron is key
Both excess and deficiency can be a problem if not managed right
The recommended amount for the majority of adult men is 8mg a day
The recommended amount for the majority of adult women is 15-18mg a day, but unlike men, women’s iron levels are more susceptible to change due to menstruation and menopause
Vegans and vegetarians who consume a balanced diet are at no greater risk than meat-eaters for iron deficiency
Using plant-based sources of iron over animal-based sources are overall safer for longer-term health since they avoid heme iron consumption
Heme iron may be absorbed better but comes with higher rates of long term health issues
Heme iron has been linked to cardiovascular disease, neurological issues, type 2 diabetes, and cancers.
Eating more plant-based foods that are high in a variety of other beneficial nutrients to make up for a slightly lower absorption rate of iron is a relatively easy solution to the “vegan iron dilemma” and avoids all the negative complications that may come from using meat as your primary iron source.
Foods containing Vitamin A and C help with iron absorption.
Foods containing phytates, oxalates, polyphenols, and calcium hinder iron absorption.
The general takeaway for both vegans and non-vegans is to eat a varied helping of plant-based foods high in iron as part of your regular diet and for non-vegans to increase the amount of plant-based iron sources and decrease the number of meat sources to lower overall risk of future health issues.
Great options are, spinach, quinoa, dried fruit, cashews, and white beans to name a few
Check out the top 16 vegan sources high in iron to give your diet a healthy plant-based iron boost.
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