Is Popeye eating the wrong vegetable?

Spinach makes you stronger…

Or so Popeye thought.

There is a current debate going on amongst academics (with apparently too much time on their hands!) about a misplaced decimal point in the original research that cited spinach as a great source of iron.

Dr Mike Sutton has written an analysis about the history behind Popeye’s adoption of Spinach.

He then looks at the claims that Popeye was responsible for a 33% increase in USA Spinach consumption in the 1930s

This is a great piece that should be read by all undergraduates about why Statistics do matter but their interpretation must be relevant and taken in context.

“Socially embedded codswallop”

Sutton’s examination of the evidence is quite thorough and it shows how quoting “facts” or journal articles without reference, can quite easily then become “socially embedded codswallop”.

Spinach is one of several “superfoods” that are quoted as having special values, mainly because of its iron content”. In fact E.Segar (Popeye’s creator) chose Spinach because of its Vitamin A content, rather than its iron content.

Iron content

Spinach is a source of non-heme iron, which is usually found in vegetable sources. Unlike heme iron found in animal products, non-heme iron is not as easily absorbed by the body.

That is because Spinach also contains oxalic acid (sometimes referred to as oxalate). Oxalic acid binds with iron, hence inhibiting its absorption.

The iron content changes with cooking too. According to the USDA National Nutrient Database, one cup of cooked spinach provides ~3.5mg of iron whereas a cup of raw spinach only contains 1 mg of iron.

So, Spinach does contain Vitamin A, and some degree of iron, but isn’t a substitute for other meat and fish sources of iron.

The take home message here is NOT “Spinach is bad for you”.

Instead, it is check the evidence, and put stats into context.

Thanks to Anton Parker for the tip (one of the aforementioned Academics with too much time on their hands!)

Read our guide to the best vegetables you should eat.