The followers of organic often advance the principle of precaution to justify their choices of production or consumption. In the absence of certainty as to the medium or long term effects of various potentially harmful substances, they prefer, as far as possible, to avoid them completely. Thus, in the organic sector: no pesticides, growth hormones or antibiotics.

Also, many producers and consumers argue that organic foods are more nutritious and provide more vitality than other products.

Are they right? Researchers are far from agreeing on these questions. Some favor the organic sector, others consider that organic foods offer little advantage over those of conventional agriculture.

In 2009, the authors of a synthesis of studies¹, sponsored by the UK Food Standards Agency (FSA), concluded that organically grown foods do not contain more nutrients than conventionally produced foods.

According to nutritionist Alan Dangour, lead author of the FSA-funded study, “It is important for consumers to know that there is no strong evidence on which to base their choice of organic food based on of increased nutritional value compared to conventionally produced foods ”.

Expressing another point of view, the Quebec nutritionist Anne-Marie Roy affirms that “the data of the British study do not allow to declare that organic farming does not confer any advantage to food from a nutritional point of view”.

She notes that, overall, the 55 studies selected for review indicated a clear trend in favor of increased nutritional value for at least 5 basic nutrients. The only difference found for common products is their higher nitrogen content, which is not considered good news by the World Health Organization which attributes public health concerns to high nitrogen levels in Food.

Anne-Marie Roy also points out that other researchers who analyzed the same studies came to very different conclusions. This is particularly the case of the American team of Charles Benbrook, scientific director of The Organic Center, which analyzed, in 2008, studies published on this subject.². American researchers then concluded that organic farming products had a superiority of around 25% for 11 basic nutrients.

Pesticides are “poisons” designed to destroy all kinds of “harmful” plants, insects and fungi. As such, they can constitute a real danger to public health. There is a consensus to limit their use, at least for the most toxic of them. We are constantly trying to define the degree of risk they present and to know how much we are willing to tolerate collectively.

What is the quantity of pesticide residues that we find in the food we eat? This question is of concern to health authorities. We suspect these residues of causing, in the long run, harmful consequences for health: appearance of cancers, disruption of growth of the fetus and the child and disturbance reproductive, endocrine, immune and nervous systems³. But the identification of specific effects is controversial because of the limited research done on humans and the contradictions between the results of studies published so far. The evidence is inconclusive. It cannot therefore be said that pesticides are associated with specific health problems.

In any event, study after study, we find that the quantities of pesticide residues found in various products generally comply with official standards. Thus, in nearly 80% of fresh foods grown in Canada, no traces of pesticide residues were detected in 2003-2004. About 20% contained it – but below the limits set by Health Canada – and only 0,7% exceeded Canadian standards. On the side of imported fresh foods and processed foods, the picture was similar or better yet⁴. In Great Britain, 70% of products are said to be residue-free⁵.

However, the results of an American study indicated, in 2000, that the average American could be exposed up to 70 times a day persistent pesticide residues in food⁶. On the occasion of a study conducted in the Seattle metropolitan area, United States⁷, measurable levels of organophosphate pesticides (persistent pollutants) were found in the urine of 109 of 110 children from 2 years to 5 years tested. The child who was not found lived in a family that only bought organic food and never used household pesticides at home.

According to François Belzile, full professor in the Department of Plant Science at Laval University in Quebec City, these quantities remain tiny. “What matters above all is to assess the relative risk. Remember, we ingest more carcinogens in a single cup of (non-organic) coffee than with all the pesticide-treated foods we consume in a year! He says.

For its part, the Standing Committee on the Environment and Sustainable Development of the House of Commons of Canada in 2000 recommended that the government develop a policy promoting the transition from agriculture dependent on pesticides to organic agriculture.⁸. This decision was taken after having read all of the scientific literature and consulted a panoply of experts.

To increase productivity and accelerate the growth of farm animals and fish, agro-industry uses various substances (hormones, antibiotics, animal meal, etc.) which are added to their feed. Growth hormones are thus found in the food chain and the effects of their accumulation in the human body are a matter of concern for scientists who associate them, in particular, with an increase in the incidence of breast cancer and with the early puberty among young girls⁹.

On the other hand, the World Health Organization has not ceased, for several years, to alert national authorities to the phenomenon of antibiotic resistance attributable to the massive and systematic use of these substances in farms¹⁰. Up to 70% of the global production of antibiotics goes to farm animals. The Food Standards Agency in Great Britain also considers that under the precautionary principle, hormones, as a growth promoter, should be banned¹¹.

Finally, despite the real shock that the mad cow crisis has caused in global agricultural circles, not all countries have yet banned animal meal from herbivore farms, a practice associated with transmission to the herbivore. human variant of bovine spongiform encephalopathy¹². Organic farming does not allow this practice.

More and more studies show that organic foods have a slightly higher nutritional value than conventional products. However, science cannot formally affirm that this increased value has a measurable impact on health. Yet reputable researchers like cancer expert Ralph Moss^13,14 do not hesitate to assert that organic foods are better for your health, and should in particular be consumed by people with or at risk of cancer.

In his book anticancer¹⁵, Dr. David Servan-Schreiber recommends, to prevent cancer and to treat it when it is reached, to favor foods from organic farming, for two reasons: they are free of pesticides and herbicides with the effects carcinogens and are generally richer in protective substances, such as antioxidant phenols.

Essential nutrients

The results of a review of 41 comparative studies¹⁶ indicate that organic foods (fruits, vegetables and grains) generally contain more vitamin C, iron, magnesium and phosphorus than foods from conventional agriculture and less nitrates (nitrogen compounds) than the latter. But this small difference would have little impact on overall health.

In general, organic foods do not contain more protein and most essential vitamins and minerals than those from conventional agriculture. Nutritionists also believe that, even if this were the case, this difference would not have a major effect on public health since there are no major deficiencies of these nutrients in the populations of industrialized societies.

Secondary metabolites

According to some researchers, it is more in terms of secondary metabolites that organic foods could have advantages.¹⁷. Unlike major nutrients, secondary metabolites are not considered essential, but they still play a crucial role in health.

This is particularly the case of antioxidants which make it possible to counter oxidative stress, which is associated with several diseases, including cancer. Comparative analysis results indicate that organic foods contain more antioxidant phenolic compounds than their counterparts from conventional agriculture¹⁸.

Scottish researchers also compared the content of salicylic acid, an antioxidant and anti-inflammatory compound naturally found in vegetables in commercial soups made with organic vegetables and that of similar soups containing vegetables from conventional agriculture. Their results indicate that organic vegetables contain more salicylic acid¹⁹. According to the researchers, it is possible that this increased content provides significant protection against certain diseases, including cardiovascular disorders.

“So far, 14 studies have compared the content of polyphenols (antioxidants) in organic fruits and vegetables with that of products from conventional agriculture. Ten gave the advantage to organic products ”, specifies Marie Josèphe Amiot-Carlin, research director at the National Institute of Agronomic Research in Marseille. One possible explanation: organic plants would produce more of these natural compounds because they are under more stress than those from conventional agriculture, chemically protected by pesticides.

But, again, the direct effect of these increased concentrations on health is not demonstrated. For example, a study found that organic tomato purees contained more vitamin C, carotenoids, lycopene and polyphenols than their conventional counterparts. On the other hand, analyzes revealed no difference in the level of these elements in the blood of people who had consumed, for 3 weeks, these purees or ordinary purees.

Food experts are unanimous: the most important thing is to eat a balanced and varied diet. According to nutritionist Hélène Baribeau, it is important to eat a lot of fruits and vegetables and not to abuse sugars, fats (especially the “bad” ones), nor salt. “If basic needs have not been met, organic food will not fill the gaps,” she stresses. “We must also favor the freshest and most complete foods possible. Organic white bread may not be the best healthy choice. Also watch out for cookies, fatty and sweet, even if they are organic! Having said that, I believe that organic foods can be a great complement to an already healthy diet. “

The P^r François Belzile goes in the same direction. He argues that we must first and foremost favor fresh and local products. “Organic products are more expensive. In my opinion, if the budget that can be devoted to fruits and vegetables is limited, it is better to buy more than to reduce their quantity to obtain them organic ”, he pleads.

Finally, cancer expert Ralph Moss recalls that although a study²¹ observed that organic ketchups contained significantly more carotenoids than others, they were all – organic included – usually packed with sugar¹⁴!

Read “Organic in practice”