Organic v. Nonorganic Food: What Are You Getting for Your Organic Dollar?
This article is based on thoughts drawn from a keynote address given by Dr. Carlo Leifert (pictured above) at the 2017 Canadian Organic Growers Toronto Organic Consumer Conference called “Organic: Inspiring Change.” Dr. Leifert coordinated a team of international experts, involving 31 research and university institutes, to study the nutrient quality of oarganic foods v. nonorganic. It revealed that nutrient levels were higher in organic foods and in some instances, up to 60% higher in several key antioxidants than conventionally grown crops. A link to the published study can be found at the end of the article.
Nutritional differences are one of the key reasons why consumers purchase organically grown food. Pesticide reduction, avoidance of GMOs, and environmental concerns are also important factors, but recent studies have brought organic food’s nutrient quality to the fore. How important are organic growing methods to food’s nutritional quality? Is there a nutritional difference between organic and nonorganic food? It is a question that generates great controversy and hype in the media. Though much is not known about exactly how nutrients function and how they benefit us, consumers, mindful of paying a premium for an organic product, are right to be hopeful that organic is better.
Dr. Carlo Leifert, a professor of ecological agriculture at Newcastle University, took on the task of coordinating a major EU-funded study that carried out a thorough meta-analysis of data on the nutritional composition of organic food. The study was in response to widely publicized research by Britain’s Food Standards Agency that fell short of collecting all the available data. As headlines proclaimed “Organic Food Not Healthier,” Carlo and his team spent two years securing data from that study, and then included additional studies that had been omitted. They analyzed the work of 343 peer-reviewed studies, compared to only 46 used in the previous study.
The team looked at a wide variety of different types of studies that compared organic and nonorganic. They looked at studies that compared foods that consumers purchase at the store. They looked at the crops and livestock produced on nonorganic and organic farms. They looked at work done in controlled field experiments that removed various environmental influences: this can include how the food is grown, where it is grown, and what type of soil it is grown in. You can see just how challenging it is to compare the diverse ways of producing food, with so many variables at play. For example, for livestock, factors such as what the animals ate, the breeds chosen, and so on, all play a role.
In synthesizing all the data for these studies using weighted analysis (a method that increases the validity and usefulness of the results), it was found that all the studies showed the same trends. These were lower pesticide residue, higher antioxidant activity, and less cadmium residue in organic crops.
The trend overall was an average of almost 20% higher antioxidant activity in organic crops. Antioxidants are the compounds that make plants more resilient and are important for our own immune systems. Individual antioxidant compounds varied in the different types of plants, but the results support the health-promoting benefits of organic. Higher levels of antioxidants have been linked with reduced risk of some chronic and neurodegenerative diseases, including some cancers.
What is one of the factors that accounts for the difference in antioxidants? In lengthy field trials at Nafterton, it was shown to be the choice of manure, not conventional, fertilization that increased the antioxidant quality in the crops. Conventional nitrogen fertilizer served to switch off the antioxidant-producing qualities in the plants.
The use of conventional fertilizers, it seems, also accounts for higher cadmium and nickel concentrations in nonorganic crops. Cadmium is a natural contaminant of some phosphorus deposits. In this study, commercial phosphorus fertilizers elevated levels of cadmium in crops, as compared to those from manured organic crops. Cadmium is particularly concerning, because it accumulates in the kidney and liver, and there are no safe levels of this toxic contaminant. More studies are required to pinpoint the actual concentration differences between organic and nonorganic, but the need is there, as existing studies indicate it to be 10 to 100 times higher in conventionally produced foods.
Studies of organic milk revealed unequivocal evidence for higher levels of omega-3 fatty acids, conjugated linoleic acids (CLA), vitamin E, and others, all important requirements for health. Diabetes, heart disease, and nervous tissue development are all impacted by lack of sufficient omega-3 fatty acids.
While there are not a lot of studies for organic meat, statistically significant evidence shows, for example, that organic meat contains more omega-3 fatty acids and vitamin E, though less iodine, which is added as a mineral to conventional feed. Iodine is important for brain development and thyroid function. Iodine supplementation is necessary in our nutrient-deficient world, but it is a complex balancing act between having too much and too little in your system. Worldwide, there is concern about too much iodine getting into the food chain, and the EU wants supplementation in livestock feed to be reduced.
Much of the reason for a higher concentration of omega-3 fatty acids is the feeding of forages like grass, clover, silage, and hay to livestock. Grass-fed meats in general are higher in omega-3 fatty acids both in conventional and organic, though organic is slightly higher. However, in grain-fed v. forage-fed beef and lamb, there are big differences in omega-3 fatty acids—especially in the long-chain fatty acids so lacking in our diets. Fresh forage is the key for these.
There is no doubt this study offers compelling evidence of statistically significant benefits from organic management on such nutrients as omega-3 fatty acids, antioxidants, and others, but is less clear on how these differences impact on human health. To date, there have been few studies done on dietary interventions with organic food. The variables to contend with can be daunting, and the timeline for these types of studies long and expensive; however, there has been some promising research.
As early as the 1990’s, Danish researchers concluded that sperm were both more numerous and more active in men working within the organic sector. Subsequent US studies have also linked low sperm count with pesticide use. Based on this finding, the Danish government decided to remove endocrine-disruptive pesticides.
Another more recent study in Sweden showed the risk of allergy and eczema in children was less for those whose families followed a biodynamic lifestyle which also involves eating organic food. This is an example of the complexity of dietary intervention studies. Many factors could be involved that also account for wellbeing in a biodynamic lifestyle, including no antibiotic use, longer breast feeding, and no MMR (mumps, measles, rubella) vaccines, for example. But there are promising linkages in the studies and the meta-analysis. It has been shown that high omega-3 intake produces less eczema in mice.
Even though the problems with a dietary intervention study are complex and controlling factors very difficult to manage, they could yield rewarding results. A French study showed that those eating organic food were less obese and overweight. The study was so large that it could adjust the results for lifestyle, even though organic consumers tend to have better diets and are perhaps more active. Yet, still the results confirmed organic had a positive impact on weight. No doubt with more studies like this, public health policies would shift.
Reduced levels of non-Hodgkin’s lymphoma were also confirmed when eating an organic diet in a 7-year study. A Norwegian study with pregnant mothers showed a reduction in preeclampsia and hypospadias in baby boys when mothers ate a diet high in organic vegetables and dairy. And the list goes on.
The fact is that much can be done to improve the quality of our food, and the evidence is mounting. The conventional agriculture system has grown dependent on inputs that are detrimental to plants, the environment, and our health. In addition, the system as it exists now is unsustainable in its use of natural resources and the damage to existing resources.
Convincing a sceptical public and vested interests of the need to change how we grow food will require further studies to examine the complete nutritional potential on health of organically grown food. It will require commitment, time, and resources. In addition, research studies that are required for the approval of new agricultural methods and products that could compromise the nutritional quality of food should also be examined with rigour and health in mind.
Organic attracts the attention of people interested in their own health and that of the planet. Whether it be elevated levels of health-promoting substances such as omega-3 fatty acids, or lower risk of pesticides and GMOs, or a more humane approach to livestock management, organic production systems are raising the bar for agriculture in general.
Who will make these decisions for us, and who will set the priorities are the crucial questions now. Thorough studies like this meta-analysis will encourage more support for the organic model, and we in turn can encourage more growers to grow organically and consumers to appreciate the value of their organic dollar.
The complete study by Dr. Leifert’s team can be found in The British Journal of Nutrition at https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/higher-antioxidant-and-lower-cadmium-concentrations-and-lower-incidence-of-pesticide-residues-in-organically-grown-crops-a-systematic-literature-review-and-metaanalyses/33F09637EAE6C4ED119E0C4BFFE2D5B1