Last week in Part IIIA of this series on food (here are the links to the previous columns Part I, Part II, and Part IIIA), I discussed two of the four biggest challenges in coming home from the grocery store with foods that supply all of our many dietary needs. This week I’ll cover the other two and share some concluding thoughts.
 

  1. Our Food Supply is Consolidating

 
When you walk down the aisles of your local grocery store, you may be struck with the impression that you are amidst the most bountiful cornucopia of foodstuffs ever assembled.  In many ways, this is true.  In a few short steps you can pick up everything from avocados to artichokes and pork to pepperoni.  However, in subtler, but significant ways, the diversity of the foods filling those aisles is diminishing.
 
Half of the broccoli in U.S. grocery stores is the same variety, Marathon.  While Marathon broccoli is a very nutritious food, consuming multiple varieties of broccoli would be even better.  Vegetable oils, despite being currently out of favor in the court of public opinion, do contain some valuable nutrients and we would be well served to consume a variety of them as well.  However, with the explosion of its production in the U.S., soy is now the source of 75% of all vegetable oil in the U.S., crowding out the potential benefits of olive, sunflower and canola oils, among others. 
 
Choices in the meat department are shrinking as well. Effectively, there is only one type of chicken and one type of turkey raised for food in the U.S.   As over-fishing depopulates our lakes, rivers and oceans, the number of choices in the seafood section is diminishing as well.  Just as eating a variety of different vegetables is good for you, if you are going to eat meats, you are better off having a wide selection rather than simply alternating between Cornish Cross chicken, the predominant variety, and tilapia.
 
As the effective number of different foods in the grocery store goes down, our chances of getting all the nutrients we require are significantly reduced.
 

  1. Food is Not As Good As it Used to Be

 
I saved this one for last because I find it to be the most troubling of the four challenges.  Other than water and carbon dioxide, all of the material which becomes a plant, be it a cucumber or a cactus, comes from the soil.  Therefore, if you grow a vegetable in a soil which has a low concentration of an important nutrient, say iron, then the vegetable will be deficient in iron. In order for a farm to produce nutritious food over the long haul, its most important mission is to continually replenish its soil by adding compost and by ensuring that conditions are favorable to the fungi, bacteria, and earthworms that help to enrich the earth.
 
Unfortunately most industrial farms do not take care of the soil.  While the “big three” nutrients that plants need, nitrogen, phosphorus, and potassium, are added back, industrial farm soil is routinely short of micronutrients (zinc, selenium, manganese, etc.), low in organic material, and nearly devoid of needed fungi and earth worms. 
 
Over time, as these soils become exhausted, the foods grown in them are less and less nutritious.  This trend has been tracked by the U.S. Department of Agriculture since the 1950s for a slate of 43 common foods grown on American farms.   The results, to me at least, are stunning.  Since the 1950s these 43 foods collectively contain 20% less vitamin C, 38% less riboflavin (an important B vitamin) and 16% less calcium! A recent study has shown that 30% of Americans have a diet which is deficient in vitamins C, E, and A, as well as magnesium.
 
Conclusion
 
Over the last two weeks I’ve walked you through the difficulties in obtaining from the current U.S. industrial farming system a diet which meets all or your body’s many nutritional needs.   Here is the capsule summary.
 

  • To maintain our health, we need to eat a large number of different food molecules; vitamins, minerals, proteins, fiber, cholesterol, fats, and a host of other chemicals.
  • The food we are buying from our grocery stores and eating in our restaurants is becoming less nutritious over time due to:

    • the processing of foods which removes a substantial portion of their nutritional value,
    • the consolidation of our food supply which reduces the variety of food options available; and
    • the decline in the nutrient content of the foods that remain as a result of soil exhaustion.

 
As I alluded to last week, these changes in our food supply have more impacts on our health than just increased rates of diabetes.  For example, a 16% reduction in the calcium content or our foods almost certainly contributes to increased rates of osteoporosis. The enumeration of other diseases related to our changing food supply will need to wait for another column.
 
So how can a Chapelboro reader make the best of our current food supply? To quote Michael Pollan, “Eat food, not too much, mostly plants”.  To the extent possible, you should try to purchase those plants at your local farmer’s market from a farmer who takes care of his/her soil.  Vegetables and meats from your local farmer are worth the extra expense because, in tangible and quantifiable ways, they have more “food” in them.
 
The origin of the phrase, “An apple a day keeps the doctor away” is a February 1866 edition of a periodical called Notes and Queries from Wales.  It appears it’s time to update this old proverb to “An apple a day may postpone your doctor visit for a day or so.”  See you at the Farmer’s Market.
 
Have a comment or question?  Use the interface below or send me an e-mail to commonscience@chapelboro.com.