Everything you ever need to know about iron absorption, anemia, boosting iron as a vegan

Posted by:Lindsay S. Nixon

When I was battling (and then recovering from) H Pylori, I developed anemia (primarily due to all the internal bleeding).

Taking iron supplements (even vegan ones) wasn't an option for my broken body as they are too constipating.

If my levels became truly alarming, I agreed to do an IV infusion, but thankfully with research and a careful "diet strategy" I got my iron and RBC back into a healthy range and wanted to share what I've learned in case it can help others! 

Maximizing your iron (vegan or not) is not the easiest of tasks (IMHO).

It takes planning and there can a sharp learning curve if you're new to "nutrition."

THAT SAID, once I compiled an exhaustive list of all the iron-inhibitors (as well iron-rich foods and iron-boosters), it was much easier for me to get my mind around how I needed to eat. If you decide to make your own list, don't be alarmed with a few ingredients overlap... it's just a little reminder that we can't outsmart nature ;)

Before I get into all the science (and explaining how iron in food is absorbed (or not) by your body), I have a few general PSAs: 

  • Celiac disease causes iron deficiency anemia due to impaired iron uptake from the duodenal lumen. (The part of the intestine (the upper intestine) that is damaged by gluten is also responsible for iron absorption). Gastrointestinal bleeding may also exist with celiac (e.g. peptic ulcer) which can contribute to blood/iron loss. If you are Celiac, please check your iron regularly. 

  • If you have anemia (but are not Celiac) talk to your doctor about getting a colonscopy. This can help rule out other causes of anemia. 

  • Avoid Non-Steroidal Anti-Inflammatory Drugs (NSAIDs can cause bleeding in the stomach and intestines which can cause iron deficiency anemia). If you have pain, use Tylenol.

  • If you want to supplement, here is what I recommend to my private clients

First, the easiest part: 

HOW TO BOOST YOUR IRON ABSORPTION 

  • Employ strategic cooking methods to degrade anti-nutrients (or preserve nutrients) -- discussed below. 
  • Add vitamin C to iron-rich foods.
  • Eliminate coffee and tea (or do not consume 2 hours before or after eating). 
  • Practice meal timing -- discussed below. 
  • Eat more iron-rich foods (list below) 
MEAL TIMING FOR IRON ABSORPTION 

In addition to avoiding coffee or tea two hours before and after eating iron-rich foods, you also do not want to eat iron inhibitors two hours before or after eating iron-rich food. (See below for a list of iron inhibitors). 

Since I don't graze or snack, and eat my meals 3-4 hours apart, this wasn't a big issue for me.

If it is for you, I suggest having an "iron day" meaning one day a week (or every 2-3 days, whatever) focus on eating only iron-rich foods paired with iron boosters.

I opted to make my lunch (or dinner) my "iron meal" each day, meaning it was composed primarily of iron-rich foods and iron boosters. To ease mental stress, I didn't worry about my other two meals, but overtime I did try to be a little more "iron conscious." 

IRON-INHIBITORS(a.k.a. things that interfere with iron; do not eat with iron-rich foods) 

  1. Tea
  2. Coffee
  3. Tannins 
  4. Phytates (or phytic acid) 
  5. Oxalates (or oxalic acid)
  6. Polyphenols 
  7. Calcium, Calcium Oxalate 

Foods containing Tannins(avoid eating with iron-rich foods)

  • coffee
  • tea (the longer tea is steeped, the more tannins it contains.)
  • red wine (the more aged, the more tannins)
  • beer
  • hard cider
  • olive oil
  • grapes
  • pomegranates
  • cranberries
  • strawberries
  • blueberries
  • apples
  • apricots
  • barley
  • peaches
  • dried fruits
  • mint
  • basil
  • rosemary
  • nuts
  • chocolate (the darker the more tannins)
  • rhubarb
  • sorghum (in many GF things)
  • corn
  • squash
  • legumes (white beans have the least amount)
  • green bananas (tannins decrease as banana ripens)

Note: tannins tend to concentrate in the peels or skins, so peeling apples etc. can reduce their tannin content. Soaking (overnight) reduces tannins in most legumes (the exception being kidney, soy, and faba beans.) Sprouting, fermenting, and boiling helps reduce tannins.

Another Note: Eating vitamin-C-rich foods (see below) right before or after you drink tea/coffee (or eat other tannins) can also help neutralize the tannins.

Foods containing Phytates (avoid with iron-rich foods)

  • Grains (wheat, oats, rice, bran, corn)
  • legumes (black beans pinto, kidney, peanut, lentils, soy, peas)
  • nuts and seeds (walnuts, pine nuts, almonds, sesame, Brazil, hazelnuts)
  • tubers (potato, beet, carrot, turnip)
  • Soaking and sprouting grains and legumes reduces phytates. (Sprout People is a great resource).

Note: Even small amounts of phytates can significantly impair absorption; However vitamin C can counteract the negative effect. Eating mineral-absorbing enhancers like garlic and onions with these foods can also help.

Note: Fermentation (with lactic acid) also reduces phytates.

Note: Phytate is also heat-resistant, so it is not easily degraded with boiling.

Food containing Calcium, Calcium Oxalate(avoid with iron-rich foods)

  • peanuts
  • spinach
  • beets
  • chocolate
  • sweet potato
  • rhubarb
  • avocado
  • orange
  • grapefruit
  • raspberries (particularly high)
  • soy
  • almonds
  • potatoes
  • navy beans
  • dates (particularly high)

Foods containing Polyphenols (avoid with iron-rich foods)

  • many supplements
  • berries (blueberries, blackcurrant, blackberries)
  • cloves
  • peppermint
  • star anise
  • oregano, sage, rosemary, thyme
  • cocoa, dark chocolate
  • nuts
  • flaxseeds
  • artichoke
  • red onion
  • spinach
  • chicory
  • shallots
  • olives
  • coffee
  • black and green tea
  • red wine
  • plums
  • sweet cherries
  • apples
  • beans (white and black have highest)
  • nuts (hazelnuts, walnuts, almonds, pecans)
  • soy (tempeh, soy flour, tofu, soy yogurt, sprouts)

Note: Polyphenols are powerful plant compounds that our body needs. They have numerous health benefits so don’t try to avoid them as much as be more strategic when and with what else you eat them with.

Note: Some evidence suggests calcium hinders iron absorption. Calcium-rich foods should not be included in meals with high iron food. Always take iron and calcium supplements at different times of the day.

Note: Soaking leafy greens can reduce their calcium oxalate. Boiling leafy greens reduces calcium oxalate (steaming and baking are not as effective).

Food rich in iron:

  • watercress
  • curly kale
  • spinach
  • collard greens
  • dandelion greens
  • Swiss chard
  • citrus
  • red and yellow peppers
  • broccoli
  • pumpkin seeds (pepitas)
  • cashew (switch to cashew creamer?)
  • pistachios
  • pine nuts
  • hemp seeds (switch to hemp milk?)
  • sunflower seeds
  • kidney beans
  • navy beans
  • chickpeas
  • soy beans, tofu, tempeh, natto
  • black eyed peas
  • pinto beans
  • black beans
  • peas
  • lima beans
  • sesame seeds
  • flax seeds
  • tomato paste
  • potatoes
  • mushrooms
  • palm hearts
  • olives
  • mulberries
  • amaranth
  • spelt
  • oats
  • quinoa
  • coconut milk
  • blackstrap molasses
  • dried thyme
  • dried fruits (raisins, apricots, prunes)
  • iron-fortified foods (e.g. some pasta, cereal, orange juice)

Note: Fermented and sprouted grains (sprouting and fermenting break down anti-nutrient compounds that negatively impact iron absorption.)

Note: Consuming foods that are rich in the amino acid lysine (quinoa, legumes, spirulina, fenugreek, tofu) together with your iron-rich meals may increase iron absorption

MAXIMIZE IRON ABSORPTION BY ADDING VITAMINS A & C

Vitamin C has been shown to enhance iron absorption. It captures non-heme iron and stores it in a form that’s more easily absorbed by your body.

The presence of vitamin A (beta-carotene) can increase iron absorption significantly.

Vitamin C-containing foods

  • citrus (orange, kiwi, lemon, grapefruit)
  • dark leafy greens
  • spinach
  • bell peppers
  • melons
  • strawberries
  • bell peppers
  • tomatoes
  • crucifers (broccoli, Brussels sprouts, cabbage, cauliflower)
  • potatoes
  • guava
  • papaya
  • pineapple
  • mango

Note: Cooking may reduce the amount of vitamin C in fruits and vegetables. Steaming or microwaving these foods may retain the most of the vitamin.

Vitamin A containing foods 

  • Leafy greens
  • orange and yellow vegetables (carrots, sweet potato, pumpkin, winter squash, summer squash, etc).
  • Tomatoes
  • red bell pepper
  • cantaloupe
  • mango
  • fortified foods with retinol (e.g. breakfast cereals)

COOKING METHOD CHEAT CHEAT 

To reduce Phytates, soak, sprout or ferment. 
To reduce Tannins, soak, boil 
To reduce Oxalate, soak, boil 

To preserve Vitamin C, leave raw, microwave, or steam 

RESOURCES: 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4541375/

https://pubmed.ncbi.nlm.nih.gov/20200263/

https://pubmed.ncbi.nlm.nih.gov/10799377/

https://www.medicalnewstoday.com/articles/325067#best-foods

https://www.hsph.harvard.edu/nutritionsource/vitamin-c/

https://www.healthline.com/nutrition/phytic-acid-101

https://www.healthline.com/nutrition/how-to-reduce-antinutrients

https://www.hsph.harvard.edu/nutritionsource/vitamin-a/

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