The Dirt On Food                            Worksheet

Is it true that Big Agriculture has totally ruined our soil, and used up practically all of its goodness, so there’s barely any nutrition left in our food? Well, no - but like all good myths, there is a small grain of truth.

Dr Karl: G’day, Dr Karl here.

Is it true that Big Agriculture has totally ruined our soil, and used up practically all of its goodness, so there’s barely any nutrition left in our food? Well, no - but like all good myths, there is a small grain of truth.

There’s claims out there that you would have to eat eight of today’s oranges to get the same amount of vitamin A our grandparents would have got from just one. Other people say that over the last century, calcium, magnesium and iron in cabbage, lettuce, tomatoes and spinach have dropped by up to 90%.

This claimed 90% reduction comes from a 2018 paper in the journal, “nutrients”. On the third page, there is a very dramatic graph, showing “average mineral content of calcium, magnesium, and iron in cabbage, lettuce, tomatoes and spinach” on the vertical axis, and years on the horizontal axis. The graph shows the three minerals measured falling from 400mg of minerals/100 grams of food, down to much less than 50. Yes, that’s dramatic! The caption below the graph spells out that “… mineral content… has dropped 80-90% between 1914 and 2018.”

Wow!!

Sounds worrying…but hang on, what’s really happening here.

There’s a big problem with the data. Out of the tiny sample of just seven data points – the data they’re basing their claims on - three are marked with asterisks. And then the tiny print reads, “Asterisks indicate numbers could not be independently verified.” So, in plain English, they’re really saying that three of the seven data points could not be proven. Not only is the data sample size tiny, it’s also pretty useless. And very significantly, one of these data points they couldn’t verify was the oldest data point from 1914 that was used as proof food used to be way more nutritious then.

The graph shows that in 1914, mineral content was around 400 mg/100g of veggies. When you try to find out where this number came from, the references send you to a book written that year, by Henry Lindlahr. It’s called “Nature Cure”and is one of the foundation texts of modern American Naturopathy. In it he made all sorts of outrageous claims. He said that you could diagnose any disease by simply looking at a person’s iris – that’s rubbish. He claimed that vaccinations against smallpox did not work, but even worse, actually caused cancer, insanity and tuberculosis. Again, total rubbish!

Was he a respected food scientist of the day, able to make precise and accurate measurements of minerals in foods? No, the exact opposite. According to his contemporary, Dr Morris Fishbein, the editor of the Journal of the American Medical Association for 25 years, “the methods of diagnosis used in the Lindlahr institution were preposterous”.

So why would anybody use this sloppy and unverified data. Well, two of the three authors of the more recent 2018 article that says food nutrition is declining are full-time employees of a company that sells wellness nutritional supplements. The third author is a paid consultant for that same company. That sounds like a conflict of interest, perhaps?

So then, what about a different paper that was published in 2004 in the Journal of the American College of Nutrition, that compared some 43 plants from the years of 1950 and 1999 – half-a-century apart. It looked at micronutrients, as well as the fat, protein and carbohydrate levels in these 43 food plants, that ranged from asparagus to watermelon.

Well, overall, in about half the nutrients, they found no change. There was a statistically significant decline in the other half. It ranged from a small 6% drop in protein to a larger 38% drop for the B vitamin, riboflavin. So how do we explain this?

It turns out that the major factor affecting the nutrient levels in any species of food crop is the specific variety, or cultivar. One study looked at some 50 varieties of broccoli. Depending on the variety, a nutrient could vary by a factor of 10. Across about 100 different varieties of tomatoes, the Vitamin C level varied by a factor of three. And calcium levels in beans can vary by a factor of two, again depending on the variety.

When farmers choose a crop, they usually look at the return in regards of the yield, disease resistance, suitability for the local climate, and so on.

But the nutrient quality of the specific variety of that food type likely never comes into it.

That’s the dirt on food!

 

Comprehension

1.  What are some of the claims made about the decline in food nutrients since 1914?

2.  What were some of Henry Lindlahr’s unfounded claims in 1914?

3.  Who was Dr Morris Fishbein?

4.  What was Dr Fishbein’s opinion of the Lindhars’s claims?

5.  What were the findings published in the 2004 Journal of the American College of nutrition?

6.  What turned out to be the major factor affecting nutrient levels in plants?

7.  What do farmers consider when choosing a crop?

 

Analysis – In this section you will be asked to comment on a variety of aspects of the language used in the passage including language features, context and effect.

 

1.  The dirt on food.

2.  Big agriculture has totally ruined our soil.

3.  Like all good myths there is a small grain of truth

4.  Sounds worrying…but hang on, what’s really happening here.

5.  That sounds like a conflict of interest, perhaps?

 

Summary – In 300 -500 words write a summary of the passage