Do we really believe organic food is not nutritionally superior?

BBC news announced tonight that Organic food is no more nutritious than conventional produce! This immediately caught my attention and I suspected the involvement of the Food Standards Agency. I got straight on the internet before the news reader got to this particular  story and sure enough this study was indeed comissioned by the FSA. They said that they wanted the consumer to be able to make an 'informed choice.' I agree with this statement and so this blog is intended to ensure that you the consumer can make an informed choice.

If the public are to be fairly informed then this report should have clarified how the study was run in order for them to know whether this really gave organic food a fair chance. A big factor over any meta-analysis is the criteria used to decide which studies to include and which to ignore. (A meta-analysis is where they search the scientific literature to find studies already done and try to look at all the numbers created to see if more significant information can be determined using larger numbers) In this particular instance a search of electronic databases over 50 years from Jan 1958 to Jan 2008 brought up 162 scientific articles. However, once they applied their selection criteria only 55 studies were used. The reasons why the other studies were dropped and not used in drawing their final conclusion were listed with some unusual exclusions, including:

• study did not have an english summary (abstract) - this could have excluded many valid trials performed in non-english speaking countries.
• if the study focused mainly on fertiliser regimes - surely this is a major difference with organic agriculture over conventional.
• if it focused on non-nutrient contamination like lead, cadmium and mercury - this is more likely in conventional farming and is more likely to affect health, yet they ignored these studies?
• studies involved in describing food production methods - again another significant area of concern as organic food tries to minimise the impact of processing on the orginal food!

The three types of areas that they primarily looked to included field trials, farm surveys and shopping basket comparisons. Crop comparisons in this review had to be in fields that were literally beside each other to reduce the chance of variability of environment and land. This is surprising as that is of course one of the main objectives of organic agriculture - to significantly improve the environmental factors that will improve the quality of the food grown. This criteria is highly likely to reduce the variability of nutrients between the categories. The quality of the non-organic agriculture was not stated and some farms may still work to good standards and not have organic certification. This should have been a comparison between the most commonly used methods of conventional farming and the most commonly used methods of organic, not necessarily in crops immediately beside each other where cross pollination, pesticide contamination other considerations can affect each crop and reduce the differences. It is more likely that organic and conventional differences stood out in the farm surveys where they observed random samples of food from more distant farms.

The final type, the basket comparisons, is highly open to variation and many flaws have been noted with this in many other research studies. How ripe is the product when sampled? Ripeness directly affects the nutrient content. How long did it have to travel before testing. Many organic fruits available in supermarkets throughout the UK are imported from New Zealand, South Africa and the USA. The longer the fruit is transported the greater nutrient decline will occur. According to Friends of the Earth apple orchards in the UK have declined by over 60% since 1970 due to the demand for cheaper fruit from abroad, even China. Nutrient density will certainly decrease with this increased distance. What category of conventional produce was the organic compared to? Extra, class 1 or class 2, and this year the EU has changed standards to allow the sale of fruit that does not meet even class 2 standards. There are likely to be smaller differences between the highest grade and organic, but not everyone purchases the highest grade, especially in the economic climate where many may be choosing lower grades as they cost less. It is would be expected that nutritional differences between the lowest conventional grades and organic would be greater than those reported on in this study.

When we actually look at the number of crop studies that provided enough numeric nutritional information for comparison there were only 10 studies used out of the 137 crop studies included in the criteria. This considerably reduces the sample size. This report is claimed to be the largest review on organic produce that has ever been done! 10 studies included for nutrient comparison seems fairly unimpressive. There were no significant differences found in vitamin C, calcium, phosphorus, potassium, total soluble solids, titratable acidity, copper, iron, nitrates, manganese, ash, specific proteins, sodium, plant non-digestible carbohydrates, β-carotene and sulphur. Significant differences in content between organically and conventionally produced crops were found in some minerals (nitrogen higher in conventional crops; magnesium and zinc higher in organic crops), phytochemicals (phenolic compounds and flavonoids higher in organic crops) and sugars (higher in organic crops). Zinc deficiency acorss the globe is estimated at about 1/3 of the population with even very conservative figures suggesting at least 25% of the population lacking. The Copenhagen Consensus 2008 identified vitamin A and zinc deficiency as their number one priority to improving global welfare. If organic produce has higher zinc then this is hugely important! Estimates are that as many as 61% of the population do not get enough magnesium in their daily diet and are likely to be deficient. As this should be the 11th most abundant mineral in the body by mass, this is no minor concern as magnesium deficiency is linked with CHD, hypertension, depressed immunity, depression, diabetes, cancer, asthma, migraine and increased stress. These minerals and their importance seem to have been barely acknowledged in supporting optimal health in this FSA report.

When comparing livestock they only had 25 studies available within their criteria and when analysing nutrient numeric data only 5 of those studies provided them with enough to compare and so the other 20 were excluded. The nutrient analysis across these 5 studies  looked at the type of fatty acids whether saturated, monounsaturated or polyunsaturated (omega 6 and omega 3 included), trans fatty acids and a unspecified category. The also looked at nitrogen and ash. No analysis was made of vitamin or mineral contents in any way. This is a very limited nutritional profile to say the least. In organic food they found that nitrogen content, some polyunsaturated fats and trans fatty acid content was significantly higher. The trans fatty acid may be surprising to those who know a bit about this category of fats. However, it is standard practice under EU organic regulations that cows, sheep, venison and lamb are all reared outdoors on grasslands and pasture. Grass fed animals have been documented to have higher levels of the valuable nutrient conjugated linolenic acid or CLA. This is a type of naturally occuring trans fatty acid (a different chemical shape to the man made damaging ones)  has great health benefits for humans such as increasing bone strength and immune function whilst reducing cancer, CHD and diabetes risk. Yet again a point that seems to have been overlooked as not important compared to conventional produce.

This brings the total studies used for nutrient comparison to 10 crop studies and 5 livestock studies. Is 15 studies across 50 years of research really a solid base to make the statement that organic food is nutritionally no better than conventional food? A simple search on Google scholar for 'organic compare conventional food' brings up over 600,000 results. Now many of these may not be quality scientific journal articles but it does show how much information has been generated on this topic. It is not fair that this important issue has been grossly oversimplified for the general public. This study may indeed have looked at the debate between organic versus conventional in a different way than previously done. However, one thing is clear they have not answered vital questions in this important area of research and their study is far from conclusive!

Peter Melchett, policy director at the Soil Association said they were disappointed with the conclusions.

"The review rejected almost all of the existing studies of comparisons between organic and non-organic nutritional differences.

"Although the researchers say that the differences between organic and non-organic food are not 'important', due to the relatively few studies, they report in their analysis that there are higher levels of beneficial nutrients in organic compared to non-organic foods.

"Without large-scale, longitudinal research it is difficult to come to far-reaching clear conclusions on this, which was acknowledged by the authors of the FSA review.

"Also, there is not sufficient research on the long-term effects of pesticides on human health," he added.

Do we really need science to tell us that following the ideals of organic agriculture makes complete sense? There is no doubt in my experience that the best quality foods, like those identified on Natural Food Finder (many of which are organic) promote considerably better health and taste so much better! Bring on good food! Organic standards should be what we call conventional food!