Plant sources of iron

By February 21, 2016Blog

Meat is known to provide dietary iron supply. As the World Health Organization published its recent report on the positive link between meat consumption and developing cancer I was immediately bombarded with the following question: where do you get iron if not from red meat?

Meat and cancer

Several months ago the World Health Organization (WHO) report  shook the world. It stated that eating red meat may lead to cancer. Personally, I am very surprised at the mass excitement, since the same warning was made by the World Cancer Research Fund (WCRF) in its report back in 2007.  The report covers the findings of a half million (!) studies that have been collected and reviewed.  Based on the evidence the WCRF made certain judgments and came up with 10 plain-language recommendations for consumers. Here is Recommendation 5:

Animal foods: limit intake of red meat and avoid processed meat in general. People who eat red meat to consume less than 500g a week, very little if any to be processed.

Note: red meat refers to all mammalian muscle meat, including, beef, veal, pork, lamb, mutton, horse and goat. Processed meat refers to meat that has been transformed through salting, curing, fermentation, smoking or other processes to enhance flavour or improve preservation. Most processed meats contain pork or beef, but processed meats may also contain other red meats, poultry, offal, or meat by-products such as blood. Examples of processed meat include hot dogs (frankfurters), ham, sausages, corned beef, and biltong or beef jerky as well as canned meat and meat-based preparations and sauces.

The WHO experts concluded that each 50g portion of processed meat eaten daily increases the risk of colorectal cancer by 18%. So, it is up to you to decide if you should eat meat, as well as the amount of it in case your decision is still positive.

Iron functions in our body

Iron plays an essential role in the vital processes taking place in our body. That is, this element

  • contributes to healthy mental development in children and improves cognitive function in adults;
  • helps produce healthy red blood cells and hemoglobin;
  • is responsible for transporting oxygen around the body;
  • ensures proper functioning of the immune system;
  • plays a critical role in cell division;
  • is responsible for energy utilization within the cells.

Our organism is highly efficient at accumulating iron. Once “placed in storage” it is extremely difficult to be forced out of the body. This is why the level of iron is mostly balanced by the absorption mechanism. Thus, when iron reserves are low it is absorbed way more efficiently if compared to an iron overload condition.

Iron absorption in the body depends on the source of dietary iron. Iron can be heme or non-heme. Heme iron is only found in animal products and is more easily absorbed in the body. Non-heme iron can be found both in animal and plant products and is more poorly absorbed. About 10% of iron in a human (omnivore) body is heme, the rest is non-heme iron.  The absorption of heme iron is about 25%, whereas for the non-heme iron this value is 17%. However, it was noticed that the bodies of long-term vegetarians tend to adjust and absorb non-heme iron much better than the carnivores do. The total amounts of iron absorption vary from 35% at the growth and development stage to merely 2% in people affected by certain digestive diseases.

How much iron do we need?

Adult males need about 9 milligrams of iron daily, women need 15 milligrams. Children should receive children about 8 milligrams a day, for teenage boys and girls this value is 11 and 15 respectively.

People considered most at risk for iron deficiency are menstruating, pregnant and nursing women, teenagers, young males and females under 22, vegetarians and vegans.

Both iron deficiency and iron overload cause negative health effects.  So never take iron supplements without consulting a specialist.

Iron deficiency

Iron-deficiency anaemia and vitamin B12- or folate-deficiency anaemia have similar symptoms. That is why self-diagnosis is never a good practice.  General anaemia symptoms include: tiredness, performance decrement, lack of concentration, apathy, nausea, ear buzzing, low immune function. Specific iron-deficiency anaemia symptoms are: crumbly and spoon nails, dry skin, hair loss, mouth ulcers. Since iron plays a key role in hemoglobin (the bright red blood pigment) synthesis, iron deficiency leads to pale skin.

Plant sources of iron and slim combinations

The following foods are good plant sources of iron: tofu, soybeans, parsley, lentils, all types of beans, tomato juice, cocoa powder, dark chocolate, wheat grits and other cereals, spirulina.

Pairing iron with vitamin C improves the absorption of iron in the body. Here I suggest some combinations of foods rich in vitamin C and iron-rich foods:

  • Lemon

Sprinkle your spinach with lemon juice (spinach is an excellent source of iron but first you need to blanch the leaves in the boiling water for 5-10 seconds to reduce the level of oxalic acid which inhibits the absorption of iron), add it to tomato juice.

  • Broccoli and Brussels sprouts

Eat these green vegetables in combination with cereals, lentils, beans.

  • Bell peppers

Add bell peppers to the stews based on beans and cereals.

  • Strawberries and black currents

Add these berries to porridge and green salads. By the way, frozen berries (if you freeze them properly) contain the same amount of vitamin C as the fresh ones.

  • Sorrel

Add beans, soybeans or diced tofu to sorrel soup.

It is important to keep in mind that some products (or rather, the substances they contain) inhibit the efficient iron absorption. They are:

  • Milk (calcium in milk is considered to impair the efficient iron absorption).
  • Phytates in legumes and wholegrain cereals, as well as in other high-fiber products.

Phytates are the phytic acid derivatives. Phytic acid is mainly found in wholegrain cereals and legumes, as well as in nuts. To minimize the level of phytic acid in cereals and legumes you should soak them in water (preferably slightly acidified with, say, lemon juice or vinegar) some hours before cooking and then rinse thoroughly.

  • Oxalic acid (in raw spinach, rhubarb and sorrel).
  • Some polyphenols (such as tannins) in tea, coffee and red wine.

It is also important to take into account that iron can only be absorbed properly if your diet provides a sufficient intake of vitamin A and vitamin B2 (riboflavin).

Author Lera Krasovskaya

More posts by Lera Krasovskaya

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