06 May 2010

all carrots are not created equal

The great debate about organic food has been whether it has significant health benefits over conventionally grown food. (There are other great debates about organic food as well, but one at a time) In order to better answer this question, a little bit about soil biology is essential.

My first encounter with serious biology was as a microbiologist , this has instilled in me a great respect for soil and the myriad creatures that work to create it. Healthy soil is an ecosphere in its own right containing various species of bacteria, fungi, worms, insects and other critters which we do not fully appreciate. It smells wonderful, is rich, loamy and contains high levels of organic compounds, nitrogen, phosphorus and potassium (NPK). It has the capacity to hold water in suspension and regenerate itself season after season if managed properly.

Traveling back to the 1940s - the English agronomist Albert Howard's groundbreaking study 'An Agricultural Testament' made its appearance with strong claims that synthetic fertilizer with artificially produced NPK will deplete soil fertility in the long run. This was a man who understood soil biology profoundly and has often been quoted since in other organic literature such as Wendell Berry and Rodale. These lions of the organic food movement understood way back then that the health of soil is intricately connected with human, animal and environmental health.

Fast forward today - agriculture is heavily industrialized with a lack of understanding or respect to the limits of the natural world. In a well-managed farm, there should be no need for fertilizer or pesticides with wastes being recycled and each system nourishing the other in a continuous loop. Today even organic farms have given in to intensive agriculture, demanding supply chains and the term itself can be often misleading. More about this later.

Coming back to the question of whether organic food is healthier for you: the answer is, yes. This was confirmed in 2003 by a study in UC Davis where varieties of corn, berries were grown in neighbouring plots using different methods. They were then compared for vitamins and polyphenols. The scientists found that sustainably cultivated crops had higher levels of these nutrients. Why are polyphenols important? These are secondary metabolites manufactured by plants, in other words, they are antioxidants and we all know why these are important. The reason why organic foods contain more polyphenols is this: these compounds are released by plant to ward off pests, diseases and insects - when ingested by humans, they continue to act in much the same way. These products then are results of natural selection and the coevolutionary relationship between plants and humans.

In our modern system of agriculture we fail to respect this. Plants grown with fertilizer/pesticide intensive methods fail to produce high levels of polyphenols because they simply do not need to and also because soil fertility inspite of chemicals is less than optimal. Rich, healthy, naturally managed soil adds a subset of polyphenols called flavonols which impart characteristic taste of a fruit or vegetable.

All carrots are therefore not created equal - the way we grow it, the quality of soil, what we feed that soil all contribute towards the qualities of a carrot.

The title of this post and a lot of its material is adapted from 'The Omnivore's Dilemma' - Michael Pollan. To anyone who has not read this book, it comes highly recommended.
Photo: Akhila Vijayaraghavan ©


Ramesh said...

Superb post written by an expert, but for a layman. That's special Akhila - an expert making a simple but powerful argument in language that a layman can understand is rare. Very nice.

Akhila Vijayaraghavan said...

I'm hardly an expert Ramesh!

varsha said...

Hey Akhila! so happy to find a fellow real food enthusiast!
Couldn't agree more.

S.R.Ayyangar said...

Organic vegetables are healthy right, but how many can afford to purchase when normal vegetables itself are dearer!

Akhila Vijayaraghavan said...

@ varsha - Thank for your comment. Glad to see that you are a fellow real food enthusiast

@ SR Ayyangar - Have you ever paused to wonder why they are more expensive and why they should remain so?

deepraj jha said...

wen u said,people listen...coz i am a layman in front of someone who knows molecular biology...;)...really beautiful post..www.jhadeeprajjha.blogspot.com (take a trip)...

Akhila Vijayaraghavan said...

Thanks! Glad you enjoyed the post :)

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