KaiserScience

Organic food

“People got in their head, well, if it’s man-made somehow it’s potentially dangerous, but if it’s natural, it isn’t. That doesn’t really fit with anything we know about toxicology. When we understand how animals are resistant to chemicals, the mechanisms are all independent of whether it’s natural or synthetic. And in fact, when you look at natural chemicals, half of those tested came out positive [for toxicity in humans].” –Bruce Ames

Organic food is food produced by organic farming, a set of techniques that mixes scientific knowledge of soil depletion and enrichment with anti-scientific beliefs and myths about nature and the natural.

A key belief of groups like the International Federation of Organic Agriculture Movements (IFOAM) and the Soil Association, which oppose conventional farming in favor of organic farming, is that pesticides and fertilizers are so harmful that they should be avoided unless they are “natural.”

This belief is contradicted by the vast majority of scientific studies that have been done on these subjects (Morris and Bate 1999; Taverne 2006; NCPA study). The United States Department of Agriculture (USDA) has put in place a set of national standards that food labeled “organic” must meet, whether it is grown in the United States or imported from other countries.

“USDA makes no claims that organically produced food is safer or more nutritious than conventionally produced food. Organic food differs from conventionally produced food in the way it is grown, handled, and processed.”*

Harm from bacterial contamination is a much greater possibility from natural fertilizers (Stossel 2005: 194). (For those of you who hate John Stossel, read the newspaper. The most dangerous bacteria in America’s food supply is E. coli, which is found in abundance in cattle manure, a favorite “natural” fertilizer of organic farming.)

The residues from pesticides on food, natural or synthetic, are not likely to cause harm to consumers because they occur in minute quantities.* (This fact does not make either kind of pesticide safe for those who work with them and are exposed to large quantities on a regular basis. I refer to residues on foods you and I are likely to find on fruits and vegetable we buy at the store or market.)

Using natural biological controls rather than synthetic pesticides is more dangerous to the environment (Morris and Bate 1999). The amounts of pesticide residue produced by plants themselves or introduced by organic farmers are significantly greater than the amounts of synthetic pesticide residues.

Almost all of the pesticides we ingest in food are naturally produced by plants to defend themselves against insects, fungi, and animal predators (Ames and Gold 1997). The bottom line is that fresh fruits and vegetables are good for you and it doesn’t matter whether they’re organic.

Over 30 separate investigations of about 500,000 people have shown that farmers, millers, pesticide-users, and foresters, occupationally exposed to much higher levels of pesticide than the general public, have much lower rates of cancer overall (Taverne 2006: 73.)

Groups like IFOAM refer to synthetic pesticides as “toxic,” even though the amount of pesticides people are likely to ingest through food are always in non-toxic amounts.

Many toxic substances occur naturally in foods, e.g.,arsenic in meat, poultry, dairy products, cereals, fish, and shellfish, but usually in doses so small as not to be worthy of concern. On the IFOAM website you will find the following message:

Although IFOAM has no official position on the quality of organic food, it’s easy to conclude that the overall nutritional and health-promoting value of food is compromised by farming methods that utilize synthetic fertilizers and toxic pesticides.

It’s easy to conclude—as long as you ignore the bulk of the scientific evidence that is available.

the myth of organic superiority

The evidence for the superiority of organic food is mostly anecdotal and based more on irrational assumptions and wishful thinking than on hard scientific evidence. There is no significant difference between a natural molecule and one created in the laboratory. Being natural or organic does not make a substance safe* nor does being synthetic make a substance unsafe. 

Organic food does not offer special protection against cancer or any other disease. Organic food is not “healthier” than food produced by conventional farming, using synthetic pesticides and herbicides. Organic farming is not necessarily better for the environment than conventional farming. There is scant scientific evidence that most people can tell the difference in taste between organic and conventional foods. The bottom line is: fresher is better. Organic produce that travels thousands of miles to market is generally inferior to the same produce from local farmers, organic or not.

Is there any difference between organic and conventional fruits and vegetables? According to one scientific paper, there are several differences:

Based on the results of our literature review and experiment we conclude that there are substantial differences between organic and conventional fruits and vegetables. They differ with respect to production method, labeling, marketing, price and potentially other parameters.

You don’t need to do a scientific study to know that organic foods are produced differently from conventionally farmed foods. Anyone who has been to the market knows that you will pay substantially more for food labeled “organic.”

… The aforementioned scientific study did find that the literature provides evidence for one nutritional difference between organic and conventional foods: vitamin C was found to be higher for organic food.

coddling by the media

The way the media treat “green” issues accounts for one reason that the organic-is-better myth is pervasive. Here’s an example from BBC News:

Growing apples organically is not only better for the environment than other methods but makes them taste better than normal apples, US scientists say.

The study is among the first to give scientific credence to the claim that organic farming really is the better option.

The researchers found organic cultivation was more sustainable than either conventional or integrated farming, which cuts the use of chemicals.

The scientists, from Washington State University in Pullman, found the organic apples were rated highest for sweetness by amateur tasting panels.

They reported: “Escalating production costs, heavy reliance on non-renewable resources, reduced biodiversity, water contamination, chemical residues in food, soil degradation and health risks to farm workers handling pesticides all bring into question the sustainability of conventional farming systems.”

The headline for the story reads: Organic apples tickle tastebuds.

Most people might stop reading the story after five paragraphs of nothing but positive statements about organic farming and the mention of a number of problems ahead for conventional farming. For those who persevere, however, the following bits of information are also provided:

…organic farming systems were “less efficient, pose greater health risks and produce half the yields of conventional farming”.

…the tests “found no differences among organic, conventional and integrated apples in texture or overall acceptance”.

…Growers of more sustainable systems may be unable to maintain profitable enterprises without economic incentives, such as price premiums or subsidies for organic and integrated products.

Apparently, the measure used to determine that organic farming was “better for the environment” was based on physical, chemical, and biological soil properties. The scientists created their own index and found that organic was better mainly because of the addition of compost and mulch.

Certainly, there are going to be some organic farms that use methods of composting and mulching that improve growing conditions. But there are also methods conventional farmers can use to accomplish the same thing.

Finally, there are some organic farmers who used methods of composting and mulching that don’t improve anything except the chances of bacterial infection. Only a “green” journalist or scientist could turn being less efficient, posing greater health risks, no different in texture or appearance, and producing half the yields of conventional farming into “better than conventional farming.”

I’ll provide just one more example of how the media and scientists with agendas distort the results of scientific studies that compare organic with conventional agricultural practices. In 2003, Alyson Mitchell, Ph.D., a food scientist at the University of California, Davis, co-authored a paper with the formidable title of “Comparison of the Total Phenolic and Ascorbic Acid Content of Freeze-Dried and Air-Dried Marionberry, Strawberry, and Corn Grown Using Conventional, Organic, and Sustainable Agricultural Practices.”

The article was published in the Journal of Agricultural and Food Chemistry, a peer-reviewed journal of the American Chemical Society. The article got some good press from “green” journalists, who proclaimed that the study showed that organic foods have significantly higher levels of antioxidants than conventional foods. 

(Examples of glowing press reports can be found here and here.) There is a strong belief among promoters of organic foods that there is good scientific support for the claim that diets rich in antioxidants contribute to significantly lower cancer rates. 

The data, however, do not support this belief. “Study after study has shown no benefit of antioxidants for heart disease, cancer, Parkinson’s disease, Alzheimer’s disease, or longevity” (Hall 2011).

The study compared total phenolic metabolites and ascorbic acid in only two crops, marionberries and corn. Both crops were grown organically and conventionally on different farms. The organic berries were grown on land that had been used for growing berries for four years; the conventional berries were grown on land that had been used to grow conventional berries for 21-22 years.

The crops were grown on different soil types: the organic soil was “sandy, clay, loam”; the conventional was “sandy, Ritzville loam.” The soil for the conventional corn had been used before for wheat; the soil for the organic corn had been used for green beans. The conventional farm used well water; the organic farm used a combination of well and creek water. (I don’t mention the strawberry listed in the title of the article because no organic strawberries were tested.)

As you can tell from the title of the article, the metabolites measured were not taken from fresh berries or corn but from samples that had been freeze-dried and air-dried. Though not mentioned in the title, the scientists also compared samples that were simply frozen.

The data provided by the authors in their published study shows clearly that there was not enough measurable ascorbic acid (AA) in either of the marionberry samples to compare the organic to the conventional. As already noted, no organic strawberries were studied. There was not enough measurable AA for the freeze-dried or air-dried corn to be compared.

So, the only data on AA is for the frozen corn: organic had a value of 3.2 and conventional had a value of 2.1. You can read the study yourself to find out what these numbers represent, but whatever they represent they do not merit the conclusion drawn by the authors of the study: “Levels of AA in organically grown … samples were consistently higher than the levels for the conventionally grown crops.”

The study also compared what it calls “sustainable agricultural practices” to organic and conventional practices. Sustainable practices in this study included the use of synthetic fertilizers.

“Our results indicate,” the authors write, “that TPs [total phenolics] were highest in the crops grown by sustainable agricultural methods as compared to organic methods.” Dr. Mitchell is quoted in the press as saying that their study “helps explain why the level of antioxidants is so much higher in organically grown food.” Yet, her study clearly states that the evidence for this claim is anecdotal. In fact, the authors write of the comparative studies that have been done:

These data demonstrate inconsistent differences in the nutritional quality of conventionally and organically produced vegetables with the exception of nitrate and ascorbic acid (AA) in vegetables.

distortion of evidence by scientists

One thing these “green” advocates are good at is distorting data to make lead appear to be gold. Another study led by Mitchell claims that organic tomatoes have “statistically higher levels (P < 0.05) of quercetin and kaempferol aglycones” than conventional tomatoes. The increase of these flavonoids corresponds “with reduced manure application rates once soils in the organic systems had reached equilibrium levels of organic matter.”

In fact, the study suggests that it is the nitrogen “in the organic and conventional systems that most strongly influence these differences.” The authors suggest that “overfertilization (conventional or organic) might reduce health benefits from tomatoes.” The argument is that the flavonoids are a protective response by the plants and one of the things they respond to is the amount of nitrogen in the soil.

In any case, the thrust of these and similar studies is that both organic and conventional crops can be manipulated to yield higher levels of antioxidants. At least one study has found “organic food products have a higher total antioxidant activity and bioactivity than the conventional foods.”* That study, however, involved only ten Italian men, aged 30-65 years.

I have to say that I am underwhelmed by the studies I have reviewed that claim to have found organic foods are more nourishing or healthy than conventional fruits and vegetables. At present, there is no strong body of scientific evidence that supports the contention that organic fruits and vegetables are superior to conventional produce.

A best case scenario for the organic folks would be that to achieve the recommended nutrients from five helpings a day of fruits or vegetables you might have to eat four or five more conventionally grown strawberries or two or three more baby carrots to get the same amount of vitamins, minerals, or antioxidants as provided by organic fruits and vegetables. But I’m not sure the evidence supports even that weak position.

History of the term “organic”

The term ‘organic’ as a descriptor for certain sustainable agriculture systems appears to have been used first by Lord Northbourn in his book Look to the Land (1940).

“Northbourn used the term to describe farming systems that focused on the farm as a dynamic, living, balanced, organic whole, or an organism.”* T

he term ‘organic’ was first widely used in the U.S. by J. I. Rodale, founder of Rodale Press, in the 1950s. “Rodale failed to convince scientists of the validity of his approach because of his reliance on what were perceived to be outrageous unscientific claims of organic farming’s benefits.”*

The USDA standards for organic food state:

Organic food is produced without using most conventional pesticides; fertilizers made with synthetic ingredients or sewage sludge; bioengineering; or ionizing radiation.

These standards capture the essence of the organic mythology:

1. Conventional pesticides should be avoided.

2. Synthetic fertilizers should be avoided.

3. Food should not be genetically altered.

4. Food should not be subjected to ionizing radiation.

The bit about sewage sludge is there because some organic farmers follow the “law of return” as proposed by Sir Albert Howard (1873-1947), a founder and pioneer of the organic movement. He advocated recycling  all organic waste materials, including sewage sludge, in farmland compost. The practice of adding human and animal feces to the soil is an ancient practice found in many cultures even today.

The fact that these cultures developed their practices without benefit of modern knowledge of such things as bacteria or heavy metals is trumped by the romantic notion that farm life was idyllic in those times and places when life expectancy was half that of today.

Rudolf Steiner, the founder of a set of superstitious agricultural practices known as biodynamics, also advocated using manure as fertilizer but it had to be prepared according to a magical formula based on his belief that cosmic forces entered animals through their horns. Steiner also romanticized farming. Commenting on some peasants stirring up manure, he said:

“I have always had the opinion … that [the peasants’] alleged stupidity or foolishness is wisdom before God [sic], that is to say, before the Spirit. I have always considered what the peasants and farmers thought about their things far wiser than what the scientists were thinking.”* 

Steiner gave lectures on farming, but did no scientific research to test his ideas.

A central concept of these lectures was to “individualize” the farm by bringing no or few outside materials onto the farm, but producing all needed materials such as manure and animal feed from within what he called the “farm organism.”

Other aspects of biodynamic farming inspired by Steiner’s lectures include timing activities such as planting in relation to the movement patterns of the moon and planets and applying “preparations,” which consist of natural materials which have been processed in specific ways, to soil, compost piles, and plants with the intention of engaging non-physical beings and elemental forces. Steiner, in his lectures, encouraged his listeners to verify his suggestions scientifically, as he had not yet done.*

Steiner opposed the use of synthetic fertilizers and pesticides, not on scientific grounds but on spiritual grounds. He claimed there were “spiritual shortcomings in the whole chemical approach to farming.”* He had a mystical idea of the farm as an organism, “a closed self-nourishing system.”*

This article has been excerpted from The Skeptic’s Dictionary,  http://skepdic.com/organic.html