Organic milk and meat contain around 50% more beneficial omega-3 fatty acids than non-organic, the study published in the British Journal of Nutrition claimed.
The nutritional differences also applied to organic dairy like butter, cream, cheese and yogurt, according to the research.
The study was the largest systematic reviews of its kind and was led by Newcastle University and an international team of experts, but has been met with a mixed response.
The research confirmed that what you feed and how you treat animals affects the quality of food, Soil Association ceo Helen Browning said.
Organic farming pays off
“Scientists have shown that all the hard work organic farmers put into caring for their animals pays off in the quality of the food they produce - giving real value for money,” she said.
“Organic farming methods require all organic farmers to adopt techniques that guarantee nutritionally different foods. Following research in 2014 confirming nutritional differences between organic and non-organic crops like fruit and vegetables – we can now say for certain that organic farming makes organic food different.”
But the difference between the nutritional benefits of organic food compared with non-organic food was actually “very small indeed” if they were evaluated as part of the whole human diet, the University of Reading’s professor of food chain nutrition Ian Givens claimed.
“ … the study uses percentage increase measurements that can imply a greater change than is nutritionally relevant”, he said.
“Much emphasis is placed on the 56% higher n-3 fatty acid content of the organic milk, but this increase is in the milk fat, not in the whole milk. The effect also needs to be assessed in the whole diet.”
Study facts
- Organic milk and meat contain around 50% more beneficial omega-3 fatty acids
- Organic meat had slightly lower concentrations of two saturated fats linked to heart disease
- Organic milk and dairy contains 40% more conjugated linoleic acid (CLA)
- CLA has been linked to a range of health benefits including: reduced risk of cardiovascular disease, certain cancers and obesity
- Organic milk and dairy contains slightly higher concentrations of iron, vitamin E and some carotenoids
- Organic milk contains less iodine than non-organic milk
On average, people consume about 2.2g of n-3 fatty acids per day and switching from conventional to organic milk would increase n-3 intake by about 33mg per day, Givens claimed.
Unlikely to represent nutritional benefit
This would be an increase of only 1.5% in our total diet, he added.
“Such small changes are unlikely to represent any nutritional or health benefit,” he said.
“Organic produce isn’t more nutrient-packed in every regard, either. The lower iodine and selenium content of organic milk has been recognised before, and since milk is the greatest single source of dietary iodine, the lower value in organic milk needs to be recognised.”
Differences in content such as fatty acids or iodine occur primarily because organic animals are fed more of a forage-based diet, such as grass, than their non-organic counterparts, Givens claimed.
“You get the same kind of changes in food composition if non-organic animals are fed forage-rich diets too. It’s the choice of feed, not the organic farming method, which makes the difference,” he added.