Is organic food more nutritious?

Special to The Bovine, from Gary Wilson:

In order to determine if organic food is nutritious, it is first necessary to decide how to judge nutrition. Is nutrient content sufficient to judge the nutritional value of a food? Some examples from the papers of the late soil scientist, William A. Albrecht, Ph.D, would suggest that it is not sufficient.

Health Canada publishes the Canadian Nutrient File which reports up to 150 nutrients in over 5807 foods. Assuming that the nutrients contained in a particular food are averages determined by testing, one should ask over what range a nutrient contained in the food varies.

Nutrient Variation In Two Foods1

In 1940, the protein content of wheat varied across the state of Kansas. It went from 10% in eastern Kansas to 18% in western Kansas. The less developed soil in the west with the lower rainfall produced fewer bushels per acre while the more developed soil in the east with the higher rainfall produced big yields per acre. The bison, prior to our arrival, ate the short grasses that grew in western Kansas rather than the high yield grasses growing in the eastern portion of that state.

In an experiment soybeans were grown with increasing amounts of potassium (the K in NPK on the bag of fertilizer) while holding the calcium constant. The crop was grown with three different levels of potassium. The result was that the crop with the largest amount of potassium added increased the yield by 25%. The chemical analysis, however, revealed that the nitrogen content of the smallest crop, of the intermediate crop and of the largest crop were 2.8%, 2.5% and 2.19% respectively. The nitrogen content of the smallest crop was almost 28% more than the largest crop. The phosphorus concentration for the same three crops was .25%, .18% and .14% respectively. That is about a 78% increase in the concentration of phosphorus in the smallest crop compared to the largest crop. For calcium the concentration was .75% of the dry weight in the smallest crop and .27% in the largest crop. That is a 278% increase in the concentration of calcium from the largest crop to the smallest crop. Even with the 25% increase in yield of the largest crop, the amounts of these three nutrients in the total crop was lower than the amounts of the same three nutrients in the smallest crop.

How Cattle Choose Their Food When Given a Choice2

On the Poriot Farms near Golden City, Missouri a herd of over 100 beef cattle demonstrated how they choose their nutrition when given a choice. The cattle were sent out to graze on a virgin prairie field that had received no soil treatment. Growing in this field were bluegrass, white clover and some soybeans. The cattle, however, did not eat the bluegrass, white clover and soybeans. Instead they crossed this field going through an open gate into a field that had gown corn in the previous year but that had been left unused because of a shortage of labour. This field had received a soil treatment. Growing in this field were weeds, including cockleburrs, nettles, plantain, cheat, wild carrots, butterprint, wild lettuce, berry vines and many others. To obtain access to water, the cattle had to cross the field growing the bluegrass, white clover and soybeans daily but they refused to eat those crops, instead they returned to the unused cornfield to eat the weeds which they kept down to a short growth during the season.

The Change In Nutrient Content Between Hybrid Corn and Open Pollinated Corn3

In 1956, O.W. Wilcox published a paper called, “Inverse Yield—Nitrogen Law of Nature”. This paper showed how increasing yields per acre of different crops resulted in a higher carbohydrate content but a smaller protein content. Thus a crop like sugar cane produces a high yield per acre with a high carbohydrate content with a small protein content. By comparison, the legumes produce a low yield per acre but with a high concentration of protein. Corn lies on the graph between the legumes and sugar cane, relatively closer to the legumes than the sugar cane. When corn was hybridized, however, corn’s position on the graph moved closer to the sugar cane and away from the legumes. The hybridization of the corn resulted in the crop increasing in yield and starch content while the protein content was decreasing. Hybrid corn is genetically altered food using only genes within the species so it not considered a Genetically Modified Organism. Yet its genetics have been altered such that you can’t save the seeds from one year’s crop to grow the same crop the next year. The seeds of a hybrid crop will not produce the same crop as the parent crop. As a result, the grower must buy seeds every year (good for the seed company) and the grower is able to increase his yield (good for the grower). Since the grower is paid on yield, this looks like a good deal for both the seed company and the grower. It may not be, however, such a good deal for the person or animal that eats hybrid corn rather than open pollinated corn.

How Rabbits Eat Corn4

Three pens of rabbits were each given 500 gram allotments of cracked corn grain. The remaining grain was removed in the first pen and a new supply given after 25% of the grain was consumed. The remaining grain was removed and a new supply given in the second pen after 50% was consumed and in the third pen when 75% was consumed. The protein content of the corn fed was 7.31%. The rabbits, however, were consuming more of the germ and less of the endosperm so that they were able to increase the percentage of protein in the portion of the corn they consumed to 8.12, 7.87 and 7.53% in the first, second and third pens respectively. The rabbits were trying to reject as much as they could the endosperm, the fattening portion of the corn grain.

Changes In the Fertility of Male Rabbits Used for Artificial Insemination5

Two lots of male rabbits being used for artificial insemination were fed a legume hay that was grown in soil with two different soil treatments. The first lot received hay grown in soil treated with phosphate (the P in NPK on the bag of fertilizer) only and the second lot received hay grown in soil treated with both limestone (limestone is not a fertilizer, it’s a calcium amendment) and phosphate. The males in the lot fed hay from soil treated with phosphate only experienced changes in their semen. The volume delivered was decreasing, the concentration of spermatazoa was falling and the percentage of live spermatazoa was declining. As these changes in fertility were becoming worse over time, these males eventually showed no interest in a female in oestrus. The male rabbits in the lot being fed on the crop grown in the soil with both limestone and phosphate, however, experienced none of these symptoms. Their production and delivery of semen was normal and they immediately showed interest in a female in oestrus as soon as she was close to their pen. When the two feeds were reversed, it only took three weeks for the two lots of rabbits to reverse their sexual vigour.

Digestible Calcium and Phosphorus6

In an experiment lime was applied to part of a lespedeza hay crop. When the hay was first fed to lambs,  hay from the lime treated soil resulted in better growth in the lambs than the hay from the untreated soil. In a following trial the same hay was fed in digestion trials to rabbits. In this trial, the urine content of both calcium and phosphorus was noted. As with the lambs, the rabbits fed the hay from the treated soil showed the better growth rate. Perhaps surprisingly, the hay from the untreated soil was the better digested. Phosphorus and calcium were being excreted twice as fast in the urine of the rabbits fed the hay from the untreated soil as compared with the urine of the rabbits fed the hay from the treated soil. That the phosphorus and calcium were being excreted in the urine indicates that they were both digested and absorbed. Apparently that was not enough for the rabbits to more fully utilize the calcium and phosphorus contained in the hay from the untreated soil compared to their utilization of the calcium and phosphorus contained in the hay from the treated soil.

Conclusions

These examples taken from the papers written by William Albrecht show that there are at least two factors in determining the nutritional content of a crop. Both the type of crop (whether it’s a legume or sugarcane, or a hybrid or a non-hybrid, for instance) and the soil fertility in which the crop is grown both contribute to the resulting nutritional content of the crop. In the above example, by their behaviour, the cattle demonstrated that the soil fertility was the greater factor in their making a free choice of what plants to eat. The wheat in Kansas and the potassium experiment show that nutrient content can vary considerably in the same crop depending on soil fertility. The rabbits eating the cracked corn demonstrated their preference for the protein content and their rejection of the carbohydrate portion. This behaviour would suggest the hybridization of corn for higher yields containing less protein and more carbohydrate would not be approved by the rabbits. The feeding experiments with the male rabbits being used for artificial insemination and the experiment tracking the phosphorus and calcium excreted in the urine of rabbits illustrate that changes in soil fertility can have a more dramatic result in the physiology of the animal than the nutrient content itself might suggest. The results of these examples are not dependent on whether the crops were organically grown or not. Based on these examples, to count on organically grown food to be more nutritious would seem to be more of an act of faith than an act of reason. As shown by the fact that organic farmers grow hybrid corn, yield is more important to them than the nutritional value. If organic organizations ever get interested in nutrition, the first thing they might do is to add hybrids to their list of things that are prohibited.

The Importance of Soil Fertility in Creating Our Health

A book published in the 1950’s called “Soil Grass and Cancer”, written by Andre Voisin, deals with the relationship between the health of animals and man and the mineral balance of the soil. Some quotes from this book demonstrate that his point of view was similar to Albrecht’s:

“All of these observations serve to illustrate how very different results can be obtained from trials based on a foodstuff so variable, although identical in appearance.. It cannot be stated too often, nor sufficiently stressed, that the progress of biological and medical sciences must necessarily be slow so long as no consideration is given, either in experimentation or in dietitics, to the pedological and agronomic origin of the foodstuffs employed.”

“For all time the soil will remain the very basis of our life, in every sense of the word and from all points of view.”

“Questions of deficiency in agricultural products become subjects of interest only when they find expression in a commercial loss. As long as it is only a matter of a lower ‘biological value’ for Man, no one is concerned.”

These quotes are taken out of context. To better understand these quotes it is better to read them in the book so that they are read in context.

Most of all, perhaps the examples cited above along with so many other examples in Voisin’s book and in Albrecht’s papers show a need for a critical look at both nutritional science and agricultural science as services for the creation of animal and human health.

Volumes of “The Albrecht Papers” used in the above examples:

1/ Volume I, Chapter 25, “Soil Fertility As a Pattern of Possible Deficiencies”, 8 and 10

2/ Volume I, Chapter 21, “It’s the Soil That Feeds Us”, 6

3/ Volume II, Chapter 4, “Nutritious Feeds via Soil Fertility and Not Plant Pedigrees”

4/ Volume IV, Chapter 5, “Pastures”

5/ Volume II, Chapter 12, “Proteins for Protection and Reproduction”

6/ Volume IV, Chapter 5, “Pastures”

Gary Wilson is a member of Michael Schmidt’s Cowshare.

2 Comments

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2 responses to “Is organic food more nutritious?

  1. Interesting as always, Gary. It would be more readable if we could see graphs or tables encapsulating some of this info.

  2. Gary Wilson

    Thanks for the suggestion Karen. That is a good idea that did not occur to me. In the past, I sent articles I wrote to a friend for him to critically review before I sent them to The Bovine. Sadly, he passed away a couple of years ago.
    Yes, it would have been more readable if I had at least put in a table showing the percentages of nitrogen, phosphorus and calcium in the dry matter of the crops in the added potassium experiment along with their percentage decreases in the two larger crops compared to the smallest crop. In the same table I could have shown that, in spite of the 25% increase in the yield of the largest crop compared to the smallest crop, the total nitrogen dropped 2%, the total phosphorus dropped 30% and the total calcium dropped 46%. It is said that because there are more people on the planet, we need to increase crop yields per acre. Perhaps that could be subjected to some critical thinking.
    Incidently, total nitrogen is measured to determine the protein content. The nitrogen content is multiplied by 6.25 assuming that all the nitrogen in the food is contained in protein. This is the reason melamine was added to milk in China some time ago. Melamine is a good source of nitrogen so it looked like there was more protein in the milk than there really was. This would also apply to nitrates or nitrites taken up by crops where the conversion to protein in the plant failed to take place (like in a drought). Albrecht, in his day, criticized this test for nitrogen to determine the protein content of food as neither suitable for determining the total protein content or the quality of the protein content. The quality of the protein is determined by the distribution of the essential amino acids in the protein.
    I assume that is why Voisin used the essential amino acids that contain sulphur to determine the nutritional value of grass for cattle, rather than the protein content. Interestingly, in an experiment, when the methionine content (a sulphur containing essential amino acid) was at a maximum in the grass, the protein content was at a minimum and conversely, when the protein content was at a maximum in the grass, the methionine content was at a minimum. Farmers, of course, judge the nutritional value of forage by the protein content and the cattle pay the price.

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