You Ask, I Answer: Iron/Vegetarianism

For women with low iron stores, [who therefore] need to consume beef, does [soy ground beef] contain iron that can help keep the stores up?

-- Micah and Katie
(Via the blog)

Great question!

Let’s start with a few basics.

Iron is located in hemoglobin, a protein within our red blood cells (pictured at left).

Hemoglobin is responsible for delivering oxygen from the lungs to various body tissues so other cells – which rely on oxygen -- can use it.

Low hemoglobin levels are therefore problematic, as they result in cells not having enough oxygen delivered to them to perform their required tasks.

The recommended dietary allowance for iron is set at 8 milligrams for men and women over 50, but vegetarian men of all ages and women over 50 should be consuming approximately 15 milligrams a day.

The reason? There are two types of iron – heme and non-heme.

Heme is found in animal sources of iron, non-heme in vegetarian contributors.

Non-heme iron is not absorbed as easily, so 10 milligrams of purely non-heme iron is not sufficient.

This is not to say that vegetarian diets are inadequate; simply that they require a higher intake of iron.

This is not too difficult to do, especially given the high amount of fortified vegetarian products that provide plenty of iron.

Beans and dried fruits are also great sources of this mineral.

Keep in mind that women who menstruate have higher iron needs.

Those on omnivore diets are recommended to consume 18 milligrams a day. Vegetarian women falling into this category should be taking in 30 to 35 milligrams a day.

The issue of low iron stores is an interesting one because it often gets mixed up with iron-deficiency anemia, although they are two very different things.

Iron stores run a gamut, from "inadequate" to "excessive".

In the middle of that spectrum lies the “adequate/healthy” point.

Anemia is actually the "end stage", or lowest point, of iron deficiency.

The condition of anemia is diagnosed by looking at hemoglobin, mentioned above, and hematocrit (the number and size of red blood cells).

In anemia, there simply isn’t enough iron present to form hemoglobin. In turn, cells are not receiving enough oxygen.

Now here's where things get interesting.

Someone falling in between adequate stores and anemia has what is known as “iron deficiency.”

Iron deficiency is diagnosed by looking at levels of the transferrin -- a protein that binds to and transports iron – receptor and transferrin saturation (in other words, the percentage of molecules of transferrin that are saturated with iron).

The bad news is that standard blood tests only show hemoglobin and hematocrit.

Hence, you could very well be iron deficient and not know it.

You need to specifically ask for transferrin receptor and transferrin saturation blood labs.

This is crucial because iron deficiency affects brain function, particularly short-term memory, concentration, and cognitive processes.

What is important to know is that iron deficiency has nothing to do with the type of iron you are consuming.

If anyone tells you you need to eat meat to increase your iron stores, feel confident to tell them to read the literature.

The solution to increasing iron reserves is simply to consume more iron.

In the case of soy ground beef, two ounces contain 2 milligrams of non-heme iron. That same amount of ground beef contains approximately 1.6 milligrams of the heme variety.

Another interesting tidbit: runners -- especially vegetarian ones -- need even MORE iron.

When we exercise, we undergo a miniscule amount of internal bleeding (which is normal), thereby increasing blood loss -- and our chances of developing anemia if we are already iron deficient.

Again, what is important thing to keep in mind is that increasing body stores can be done with animal or vegetarian sources as long as the right amounts are being consumed.

There are also certain food combinations worth keeping in mind.

Vitamin C helps with absorption of non-heme iron.

So, a soy-based meal accompanied by a tomato salad or glass of orange juice will be beneficial.

There are also some components of food that will have the reverse effect and inhibit the body’s ability to absorb non-heme iron.

These include oxalates (found in spinach, quinoa, collard greens, peanuts, and strawberries), tannins (found in tea and coffee) and, more strongly, phytates (found in whole grains).

Therefore, a soy patty in a whole wheat bun with a side of spinach salad isn’t the most efficient way to include more iron in your diet.

Here’s some good news, though. Since sprouted whole grains have lower levels of phytates, you're better off enjoying Ezekiel 4:9 bread products than standard whole wheat varieties.

Many, many thanks to Dr. Domingo Piñero of New York University’s Department of Nutrition, Food Studies, and Public Health for providing a private iron 101 mini-lesson earlier today to help me answer this question as exhaustively -- and accurately -- as possible.