Sometimes I can’t open jars, or lift bookcases, or boulders, or obese children, and people always tell me that it’s because don’t get enough iron. So I tell them the story of Popeye. Not only did he get super-human strength from just eating a can of Spinach, he also became so strong that he managed to woo the sauciest minx in the sailor world – Olive. After repeating this story, many times, I thought I ought to find out if there was any truth behind it.

 Iron man

Does iron in our greens (and our meats) makes us strong? Spinach has iron in it. Iron is needed to keep our muscles happy and healthy. So yes, iron does make us strong. It is the main ingredient in a molecule called haemoglobin. Haemoglobin takes oxygen from where there is a lot of it, such as our lungs, and releases it to where it is needed, like our muscles, brain and other tissues. When haemoglobin is carrying oxygen it makes our blood red. If there isn’t a whole lot of iron around, our bodies make less haemoglobin, and our muscles get less oxygen. With less oxygen our muscles feel weaker and get tired faster, which means they sure can’t be strong like Popeye’s muscles. 

 How much iron does spinach have in it?

According to Dr. E von Wolf’s calculations published in 1870, spinach has 10 times more iron than any other green vegetable. Unfortunately, like so many other calculations published in the 19^th century; Cholera only infects the poor, violins are dangerous for women, it was wrong. In 1937 it was revealed that spinach doesn’t have 10 times the iron content of other greens but rather, that Dr. Wolf was indeed the doctor who cried Wolf. He had misplaced a decimal point in his calculations. Spinach actually has about the same iron content as a lot of other vegies, and even less than some. Cooked broccoli and cauliflower, for example, have almost double the iron content of spinach.

 Fortunately for the spinach growers of the world, before Dr. Wolf’s results were corrected, Popeye was created! In true American style, consumption of spinach in the United States grew 33 percent as adolescent boys and girls sought to be as strong as their favourite cartoon sailor. But, although spinach doesn’t have colossal quantities of iron, it still has its fair share of the stuff. 100 grams of spinach will give you around 0.9mg of iron.

  Will spinach make us strong like Popeye?

Even though spinach has iron in it, unfortunately, it won’t make us strong like Popeye. This is because trouble strikes when we look at the numbers (and even Dr. Wolf had trouble with these, so I should be careful). Women need about 15 mg/day of iron and men need around 12 mg/day to keep our muscles healthy. So Popeye would need to eat well over a kilo of spinach to get his daily requirement, which is okay, he ate about four cans an episode. But, the iron in spinach (and other greens) is poorly absorbed by the body unless eaten with Vitamin C. If iron isn’t absorbed, rather than making its way into your haemoglobin, the iron goodness will just get peed out. Considering absorptions rates of iron (only around 10 percent of iron in greens is absorbed) Popeye would have to eat over 133 kilos of spinach a day. That’s over 500 cans an episode.

 To make matters worse, Popeye’s choice of spinach, canned, actually has the least iron content of all the spinach varieties such as fresh or cooked.

 Things sure aren’t looking good for Popeye. His story seems to be made of more science myth than science magic. For now, I’m off to eat some spinach – I’ve got 499 cans to go.

 How can you get enough iron?

• There are two kinds of iron in our diets: nonheme and heme. Nonheme iron is mainly found in enriched cereals and pasta, beans, and green leafy vegetables. Heme iron is found in animal sources, like a meaty steak. The body absorbs nonheme and heme iron in different pathways, and absorption of nonheme iron is not very efficient.
• If you eat meat, and need to get some iron into your body, then go forth and eat meat! It’s the most efficient way to get iron absorbed into your blood.
• If you’re vegan or vegetarian eating vitamin C supplements with nonheme iron can increase our absorption of iron. So, drinking orange juice with your enriched cereal in the morning is a good idea.
• Plus zinc, eggs, tea, and coffee are known to decrease and inhibit nonheme iron absorption. Having a tea or coffee after your spinach packed meal can reduce your bodies’ absorption of iron.