MedicalResearch.com Interview with:
Professor Chris Seal and
Professor Carlo Leifert
Nafferton Ecological Farming Group (NEFG),School of Agriculture, Food and Rural Development, Newcastle University
Nafferton Farm, Stocksfield, Northumberland UK
Medical Research: What is the background for this study?
Response: In 2009 an FSA-sponsored study by Dangour et al. was published and concluded that there are no composition differences between organic and conventional crops and animal (meat and dairy) products. This contradicted the results of literature reviews, field experiments and retail surveys that many of the scientists involved in the EU-FP7 project QualityLowInputFoods (www.qlif.org/) had carried out or were in the process of completing in 2009.
We therefore decided to put together an international team of scientists and carry out a larger, updated systematic literature reviews and meta-analyses to determine whether or not the Dangour et al (2009) study was justified in drawing the conclusions they had. This took 5 years to complete. We reported on crops in 2014 (http://research.ncl.ac.uk/nefg/QOF/crops/) and the studies published now report the results on meat (http://research.ncl.ac.uk/nefg/QOF/meat/) and milk/dairy products (http://research.ncl.ac.uk/nefg/QOF/dairy/).
Medical Research: What are the main findings?
- both organic milk and meat contain around 50% more beneficial omega-3 fatty acids than conventionally produced products
- organic meat had slightly lower concentrations of two saturated fats (myristic and palmitic acid) that are linked to an increased risk of cardiovascular disease
- organic milk contains 40% more conjugated linoleic acid (CLA)
- organic milk contains slightly higher concentrations of iron, Vitamin E and some carotenoids
- conventional milk contained around 70% more of the essential mineral iodine and slightly more selenium
We feel the most important results in terms of nutrition is that both organic milk and meat contain around 50% more beneficial omega-3 fatty acids than conventionally produced products. Omega-3s are linked to reductions in cardiovascular disease, improved neurological development and function, and better immune function. Organic milk had 57% higher concentrations of the nutritionally most desirable, very long chain (VLC) omega-3 fatty acids eicosapentaenic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA). Fatty acid profiles in milk are known to change very little during processing in to high fat dairy products such as butter and cheese. Omega-3s are linked to reductions in cardiovascular disease, improved neurological development and better immune function. The European Food safety Authority (EFSA) estimates that average dietary intakes of VLC omega-3 fatty acids account for less than half of what we need for optium health.
The finding of substantially higher concentrations of iodine in conventional milk is also important information, especially for UK consumers, where iodized table salt is not widely available and dairy products are an important source of this nutrient. However, it should be pointed out that the Organic Milk Marketing Co-operative (OmsCo) has recently increased iodine fortification of organic dairy feeds and reports that levels of iodine in organic milk are now similar to those found in conventional milk (www.omsco.co.uk/_clientfiles/pdfs/omsco-iodine-levels.pdf).
Medical Research: What should clinicians and patients take away from your report?
Response: A switch to consuming organic milk could therefore contribute to increasing VLC omega-3 intake without adding to milk fat or calorie intake. We estimate that consuming ½ litre of conventional full fat milk (or equivalent dairy products) would supply 11% (25 mg) of the recommended daily intake of VLC omega-3 fatty acids and this would rise to 16% (39 mg) with organic milk. At average UK dairy and meat consumption levels VLC-omega-3 intakes with meat would be estimated 6-7 times those of milk. Switching to organic dairy products and meat consumption therefore allows you to substantially increase your omega-3 intake without an increase in the consumption of fat or calories.
Milk consumption is important to get enough iodine especially in countries like the UK where iodised salt is not widely available (www.gov.uk/government/publications/sacn-statement-on-iodine-and-health-2014). Pregnant woman, who have a much higher iodine and VLC omega-3 demand should, in consultation with their GPs, consider increasing their milk and dairy product (cheese, yoghurt, butter) intake and/or balancing their requirements with supplements or other dietary sources (e.g. fish) that are rich in iodine or omega-3 fats.
Medical Research: What recommendations do you have for future research as a result of this study?
Response: We need substantially more, well designed studies and surveys before we can accurately estimate composition differences in meat and also milk/dairy products from different farm animals and for many nutritionally important compounds (vitamins, minerals, toxic metal and pesticide residues), as there is currently too little data to make comparisons.
There are very few studies in which the impact of organic food consumption on human health has been investigated. In the two new systematic literature reviews we also describe recently published results from four mother and child cohort studies linking organic milk, dairy product and vegetable consumption to a reduced risk of certain diseases. This included reduced risks of eczema and hypospadias in babies and pre-eclampsia in mothers (http://research.ncl.ac.uk/nefg/QOF/humans.php). We feel there is a need for additional well designed human cohort based studies and human dietary intervention studies in particular to quantify the impact of switching to organic food consumption on human health
Średnicka-Tober D1, Barański M1, Seal C2, Sanderson R3, Benbrook C4, Steinshamn H5, Gromadzka-Ostrowska J6, Rembiałkowska E7, Skwarło-Sońta K8, Eyre M1, Cozzi G9, Krogh Larsen M10, Jordon T1, Niggli U11, Sakowski T12, Calder PC13, Burdge GC13, Sotiraki S14, Stefanakis A14, Yolcu H1, Stergiadis S1,Chatzidimitriou E1, Butler G1, Stewart G1, Leifert C1.
Professor Chris Seal and Professor Carlo Leifert (2015). Organic Milk and Meat Contain About 50% More Omega-3 Fatty Acids Than Conventional Products