Monday, 4 January 2016

Organic or Conventional?

Market display of fruit and vegetables
How important is it to buy organic fruit and vegetables? Organics often cost several times more than the equivalent conventional, but is the extra spend worth it?  Non-organic fruit and vegetables are regularly sprayed with potentially toxic chemicals. Do the safety regulations work?  How toxic is conventional food? Read on to find out.
Why is organic food more expensive?

Fruit and vegetables grown using chemicals are cheaper for us to buy at the shop, but these cheaper prices do not take into account the true environmental and health costs. In organic farming, the farmer is responsible for choosing the nutrients and pest control methods he uses based upon his own expert local knowledge and ethics. In contrast, chemical-based farming requires us to trust in the research undertaken by chemical companies. It also needs us to trust government approvals processes and regulations. We also rely on those farmers to apply chemicals responsibly using recommended application rates and withholding periods before harvesting.

Conventional farming has the advantage of economies of scale. Although more profitable, chemical-based mono-cultures are more susceptible to pest attack, in turn needing even more chemicals to control pests.

Organic agriculture is more often based on a diversity of crops which offer the benefit of multiple income streams, companion planting and natural pest control. The organic farmer is responsible for obtaining and applying nutrients as manures and non-chemical pest control methods.  These costs are built into the costs of organic produce. However, the more we support organic farmers by buying their produce, the lower organic prices will become over time, as their economies of scale improve.

Environmental considerations

The impact of horticultural chemicals in local soils and on waterways through wash-off is not well understood. The cumulative impacts of long term chemical exposure and the impacts of continual use of a cocktail of chemicals on the environment is also only poorly understood. The climate change implications of the manufacture, transport and application of horticultural chemicals are also not included into the cost structures of modern conventional methods.

Health considerations

The acute toxicity of agricultural chemicals is reasonably well understood- hundreds of thousands of dollars have been spent studying the human health impacts of the acute toxicity of chemical residues in our food. This forms the basis of regulations and application strategies given to farmers. However, the human health impacts of long term cumulative exposure or the exposure to a cocktail of horticultural chemicals is not well understood. For example there are over 35 chemicals approved for use on local WA strawberries with different withholding periods (the period between application and harvesting).  One wonders if these are always complied with during busy spraying and picking schedules, or what the effects of multiple trace amounts of residual chemicals might be. The ‘safe’ levels are also determined after peeling or washing as would be expected in a normal household, making it even more important to do so.

The cumulative effects of chemical application can also lead to high levels of toxic residues in soils. For example the higher Cadmium levels in phosphate rocks used to manufacture superphosphate in WA have led to unacceptable accumulations of this highly toxic heavy metal in horticultural soils. Potatoes grown in soils with high cadmium- as well as other vegetables such as leafy greens- in particular absorb this cadmium which is then transferred to the consumer. There are no safe levels of cadmium in the body as it is a toxic heavy metal, but superphosphate from Christmas island has now been banned for potatoes in W.A., due to high levels accumulated in the soils here. Organic potatoes do not have this problem.
Babies in utero and after birth, and small children, are the most sensitive to chemical residues in produce- their metabolisms are different to adults’ metabolisms, and toxins remain longer in their bodies. Even small amounts of chemicals can alter a child’s brain chemistry. Farm workers, their families and children who are exposed to these chemicals have higher levels of some cancers, ADHD, birth defects, Parkinson’s and Alzheimer’s, and lower IQ in kids. Many of these chemicals are known or suspected carcinogens or endocrine disruptors. The truth is, we do not know the long term effect of accumulated chemical residues which we are nowadays bathed in from in-utero, from our water, in the air and through our food. It makes sense to avoid them if you can, as well as support organic farmers, the environment and the future.

From a health viewpoint, it is far more important to eat an abundance of (conventional OR organic) fruit and vegetables than it is to limit fruit and vegetables because of fear over pesticide residues, and an inability to afford organics. A 2012 study estimated that increasing fruit and vegetable consumption (conventional) could prevent 20,000 cancer cases annually (U.S. figures), and 10 cases of cancer per year could be attributed to consumption of pesticides from the additional produce. There are many studies and plenty of evidence to show that eating fruit and vegetables at least 3 times a day protects against so many diseases, from hypertension and diabetes to heart disease and cancer. And even with this information being widely available, many people still do not eat sufficient fruits and vegetables on a daily basis.

Is it possible to remove pesticide residues? The answer to this very important question is: Yes, to some extent, but not completely. It is possible to wash off much of the chemical residues, or remove it by peeling some produce. Tests have shown that washing in running water is fairly effective. I sometimes use a vegetable wash to help dissolve less water soluble compounds.  Rubbing soft skinned produce such as peaches, and scrubbing carrots and potatoes can help remove residues. Peeling can be very effective at removing chemical


As with any complex story, it is important to keep things in perspective. The health benefits of more fruit and vegetables do outweigh the problem of the chemical residues.  For certain high-risk produce like potatoes, broccoli, apples and strawberries I always buy organic when available. For avocados, bananas and other things with a thick skin, I tend to buy conventional as they can be easily peeled. I look out for specials on organic produce and prefer supporting our local organic farmers and businesses as I can afford. However, our reality is that my family and I eat a lot of fruit and vegetables, and we cannot always afford to buy organic, so we simply do our best.

Many people do not eat enough fruit and vegetables, and this makes them vulnerable to many chronic diseases. Eating more fruit and vegetables- a minimum of 2 pieces or serves of fruit and 5-7 serves of vegetables a day, and preferably more- has been found to be highly beneficial. Eating organic is more than a luxury- it is important for our environment and for the health of our children, particularly those with certain chemical sensitivities. We can minimise the risks of pesticide residues in non-organic produce by washing  or peeling before eating, and by selectively purchasing organic produce as we can afford. This way, we can help balance our finite household budgets as well as improve our health.


No comments:

Post a Comment