The Truth About Soil Depletion: The Conclusions Of The Study That Feeds The Myths

One of the biggest arguments made by supplement marketers why today, more than ever, the average person needs to take supplements to obtain essential nutrients is because of increasing soil depletion of these same key nutrients.  They base their argument on a claimed USDA study that supports their assertions. As a truth hunter, I tracked down and read the oft cited study. 

First, contrary to popular assertion, it is not a study conducted by the USDA. It is simply a study using some USDA data.

Here’s the link to the study if you would like to review it yourself.

http://www.jacn.org/content/23/6/669.full.pdf+html

The study published in the Journal of The American College of Nutrition in December 2004 was titled: Changes in USDA Food Composition Data for 43 Garden Crops, 1950 to 1999.

I could summarize the study's conclusions, but I think the authors do a fine job at it so I will present the conclusions in their own words. Bold added.

“Our study also has many limitations, both chosen and inadvertent. We focused on one class of foods and an interesting biological phenomenon, without selecting foods based on their national consumption or contribution to nutrient intakes. Thus, our study is not useful for estimating possible effects on dietary intakes.”

“We lack answers to important questions. Are there real nutrient declines in staple sources of nutrients? Which nutrients are most affected? Have declines been offset by increases in other foods or by new sources of nutrients, including fortification in some countries?”

“Refined sugars, separated fats and oils and white flour and rice have all suffered losses much greater and broader than the potential losses suggested here for garden crops.”

Here’s my favorite conclusion. An old-fashioned push for eating more—wait for it-- vegetables, fruits, whole grains, nuts and beans. Wow, what a novel idea. By the way, note no reference to taking supplements.

“Thus, for those concerned about nutrient losses, the most important measure is to partly replace these known-depleted staples with more nutrient-dense whole foods, especially vegetables, fruits, whole grains, nuts and beans.”

Finally, here’s why the supplement marketers arguments never made sense to me.

“Plant cells require most human nutrients for their own functioning. They cannot grow, much less be viable commercial food crops, without synthesizing or acquiring their own needed levels of a broad range of nutrients. Thus, no whole plant food can be as broadly depleted of nutrients as are refined sugars and separated fats and oils.”

Well, I hope this finally puts to rest the major argument made by supplement marketers to buy their products. Of course, when that argument fails, they simply resort to their secondary claim that Americans can’t find the time or money to properly eat vegetables, fruits, whole grains, nuts and beans. Here’s the rub. Those who care about their health do. These are typically the same people who take supplements because they have been convinced that this is the best way to optimize their health. Now that you know the facts, if you care about your health, then eat whole foods and leave the supplements to the more easily fooled.