A new scientific review has made claims that organic foods are higher in nutrients and lower in pesticides compared with those grown in the now conventional method of intensive farming.
The review encompassed 343 previous peer-reviewed studies, assessing crop composition and foods, and the authors concluded that organic crops had higher levels of certain health-giving compounds known as antioxidants, including polyphenols, flavanols and anthocyanins.
"Many of these compounds have previously been linked to a reduced risk of chronic diseases, including cardiovascular disease and neurodegenerative diseases and certain cancers," the authors wrote.
The authors of the reviews comprised an international team of scientists who looked at all available literature and compared the chemical content of foods – primarily cereals, vegetables and fruit – and crop-based products, such as seed oils, wine and baby food. The meta-analysis indicated that the differences between organic and non-organic varieties were "significant and meaningful".
Lead author Prof Carlo Leifert of Newcastle University said: "This study demonstrates that choosing food produced according to organic standards can lead to increased intake of nutritionally desirable antioxidants and reduced exposure to toxic heavy metals."
However, levels of proteins, amino acids and nitrogen were lower in the organic crops sampled, possibly as a result of excessive use of nitrogen-containing fertilizers in conventional crops.
The new review, which was published in the British Journal of Nutrition, was partly funded by the Sheepdrove Trust, an organic farming charity, opening the door for critics to suggest that the resulting claims have been overstated to promote organic farming.
Experts opposing the results of the review argued that the differences between the organic and non-organic crops were not substantial enough to warrant the public paying more for organic varieties. This opinion was supported by the findings of two previous reviews: a 2009 Food Standards Agency report led by Dr Alan Dangour analysed 55 studies and found organic and non-organic foods were "broadly comparable" in their nutrient content, and in 2012, a Stanford University study analyzed 237 papers and concluded that: "No consistent differences were seen in the vitamin content of organic products, and only one nutrient – phosphorus – was significantly higher in organic versus conventionally grown produce."
Prof Leifert defended his findings, explaining that "the main difference between the two studies is time. Research in this area has been slow to take off the ground, and we have far more data available to us now than five years ago" but these conclusions were disputed by two independent nutritional science experts.
Prof Tom Sanders, head of the Diabetes and Nutritional Sciences Division at King’s College London’s School of Medicine, said: "This article is misleading because it refers to antioxidants in plants as if they were a class of essential nutrients, which they are not.
"In terms of macronutrients (protein, carbohydrate, fat), the organic products contained less protein. Other nutrient differences were trivial and well inside the normal range of variation that occurs with different varieties, soil types and variations in weather.
"This study provides no evidence to change my views that there are no meaningful nutritional differences between conventional produced and organic crops."
Prof Richard Mithen, leader of the Food and Health Programme at the Institute of Food Research, added: "There is no evidence provided that the relatively modest differences in the levels of some of these compounds would have any consequences (good or bad) on public health.
"The references to ‘antioxidants’ and ‘antioxidant activity’, and various ‘antioxidant’ assays would suggest a poor knowledge of the current understanding within the nutrition community of how fruit and vegetables may maintain and improve health."
Dr Alison Tedstone, chief nutritionist at Public Health England, said: "PHE welcome this addition to the evidence base but we cannot assess the potential impact of organic foods on public health from this study alone."
Professor Leifert’s study did note, however, that "it is important to point out that there is still a lack of knowledge about the potential human health impacts of increasing antioxidant intake levels and switching to organic food consumption."
For now, then it is not clear whether public health would be better served by just eating larger quantities of fruit and vegetables which are generally accepted to be a crucial part of a healthy diet:
"Ultimately, we all need to eat more fruit and vegetables regardless of whether they are organic or not” commented Dr Alison Tedstone, Public Health England.
If we ingest large quantities of pesticides via the ingestion of conventionally grown food then this risk needs to be factored into an overall approach to obtaining an optimum health-giving diet. Whether the overall benefit of eating larger quantities of fruit and vegetables offsets the additional pesticide intake is not yet known, but organic farming is not limited only to this type of produce and also extends to include meat and grain production, so ingesting non-organic foods across all food groups could have a detrimental effect.
Another new study has added weight to this argument, with disturbing findings being revealed about the quantities of pesticide residues in non-organic bread.
Though the results of this study, conducted by Pesticide Action Network (PAN UK), have been challenged, certain facts regarding non-organic foodstuffs cannot be disputed: over 60 percent of breads in the UK have been found to contain pesticide residues, according to recent analysis of government data. Multiple toxins were found in 25 per cent of the loaves, and experts are genuinely concerned about the risk of pesticide exposure:
“There is the possibility of harm from the repeated ingestion of low doses of pesticides and no one has done research on the impact of the cocktails of pesticides we are all exposed to. We are all being experimented on without our consent,” explained study author Nick Mole from PAN UK.
PAN UK’s research incorporates data generated by the Department for Environment, Food & Rural Affairs’ (DEFRA) expert committee on pesticide residues in food (PRIF), which indicate that residue levels detected in Britain’s bread fall shy of the “maximum residue level” (MRL): the “highest amount of pesticides expected in food” if they are administered correctly to crops. Following the government-sanctioned tests, PRIF experts stated they “did not expect these residues to have an effect on health.”
Mole hotly contests this viewpoint, stating that MRLs are not an accurate means to assess the cumulative effect of pesticides on human health, only whether or not they have been applied to the crops in amounts that fall within set guidelines.
His research, which was published last Wednesday, indicates that bread samples showing worrying levels of multiple pesticide residues have more than doubled since 2007.
PAN UK found that British bread typically contains high levels of glyphosate and chlormequat, two substances that have been linked to serious health concerns. Glysophate has been linked to “cancer, birth defects, and neurological disease such as Parkinson’s,” states the organisation, and confirmed that the Netherlands aims to implement certain bans on the use of the chemical from 2015, while Brazil’s government is also considering banning it as a result of its alleged links to kidney disease.
A study conducted by the UN’s Food and Agriculture Organization (FAO) found Chlormequat to be linked to developmental toxicity in animals though its effects on humans is not widely researched.
“The presence of pesticide residues in our food and our subsequent ingestion of them is not something that anybody should welcome. We are in effect being poisoned against our will with the full knowledge of the growers, retailers and regulatory bodies that provide our food or are tasked with making sure it is safe,” Mole stated following the release of Pan UK’s research.
“The report shows that pesticides residues in non-organic bread have doubled from 2001-2013 and this along with recent reports linking pesticides with damage to wildlife including bees, is extremely worrying and needs to be addressed,” commented Catherine Fookes, campaign manager for the ‘Organic Naturally Different’.
Mole is actively encouraging the public to switch to organic bread where possible in order to “significantly reduce” their exposure to pesticide residues, though the increased costs of organic produce often affect consumer purchasing. Pan UK have asked the British government to take action to reduce these pesticide residues as a matter of urgency.
It is worth remembering that choosing to buy organic foods is more than merely a decision to improve dietary health standards; it is also a conscious choice to return to more traditional farming methods that work in synergy with the earth, the seasons and local ecosystems. Organic standards are set to include far more than pesticide levels: they also generally encompass fair trade, free range and ethical labour standards. Ultimately, buying organic is a vote for more ethical food production, which impacts positively on our natural environment, and treats animals with respect.
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