I have received many questions about the results of my research analysis that I performed for my final Master’s paper. The question that I chose to answer was:
WHAT IS THE EVIDENCE TO SUGGEST A DIFFERENCE IN ANTIOXIDANT CONTENT,
IN TERMS OF VITAMIN C, BETWEEN VEGETABLE CROPS
(DISCUSSED IN CURRENT LITERATURE)
GROWN CONVENTIONALLY OR ORGANICALLY
Sounds pretty simple, right? Kind of. The results were this: 9 vegetables have been studied over the past 12 years. Tomatoes, bell peppers, potatoes, French bean, carrot, romaine lettuce, spinach, broccoli, and cabbage. For all of these, except tomatoes and bell peppers, there is no evidence to suggest that organically grown versions of these vegetables have any more vitamin C content than conventional. In some, the conventional had more vitamin C. There is good evidence, however, to suggest that tomatoes and bell peppers have more vitamin C when they are grown conventionally.
Okay, so why is this important. Vitamin C is often used as a marker for nutrition in many crops. It’s easy to isolate and easy to test. It gives an indication of the overall nutrition quality.
So, why is organic produce touted as nutritionally superior? There are theories as to why organic produce should have higher antioxidant content, but it doesn’t always prove itself to be fact in the literature. Here are the simplified versions of the two theories:
Theory #1: Plant Pathways. There are 2 plant pathways, primary and secondary. The primary pathway is used for growth, the secondary pathway is used for defense. In conventional growing systems, crops are given synthetic defenses, so they follow primarily pathway 1, for growth and to produce higher yields. In organic growing systems, crops must build up their own defenses (antioxidants) and bypass pathway 1 and switch to pathway 2, defense. This is often why organic produce is smaller.
Theory #2: Carbon Nitrogen Theory: This states that when nitrogen is readily available in soil, as in conventional systems with fertilizers, the crop will produce nitrogen containing compounds first, such as proteins. When nitrogen is not readily available/limited, as in organic systems, carbon containing compounds, such as vitamin C and antioxidants, will be created first.
Simple enough, right? Wrong again. The organic debate is much more than nutrition. As I was researching this and discussing this important topic with some of the Professors at CSU, I realized the number of factors going into the organic debate is so much more than I think about when I am at the produce department.
Some of the important factors to consider are soil sustainability, cost, pesticide use, health of the farmer, local versus organic, and nutrition.
I could go on and on about how my opinions changed while researching this over the past 18 months, but I won’t. The research is not perfect and it will get better. More to come on this important debate in the future…