Health benefits from organic diet demonstrated in rats
immune system than those on conventional diets, found a study
carried out by UK and Danish researchers.
The findings could offer some support for organic foods grown for human consumption although the researchers warned that the findings needed to be replicated in humans.
Many consumers expect organic food to be healthier than food produced under conventional conditions but there is a lack of scientific evidence to support this view.
A team from the Danish Institute of Agricultural Sciences and the University of Newcastle fed 36 rats on a diet consisting of potatoes, carrots, peas, green kale, apples, and rapeseed oil. The animals were divided into three groups, based on their diet's cultivation method.
These included organic cultivation, with low input of fertiliser and without pesticides, minimally fertilized with pesticides, and conventional growing with high input of fertiliser and pesticides.
The diets had similar energy and protein contents and had a relatively high content of fat as compared to the recommended level for rats. Vitamins, minerals and amino acids were added to all three diets, fed to the rats throughout their life.
The results showed that rats fed on organic and minimally fertilised diets had a higher content of immunoglobulin G (IgG) than rats fed on the conventionally grown diet, and the organic group also had higher vitamin E levels in their blood than those on the conventional diet, despite the similar content of vitamins in both diets.
Rats on an organic diet also showed a tendency towards a lower weight and a lower content of adipose tissue as compared to the other diets, the researchers report on the website of the Danish Research Centre for Organic Farming.
This may be related to the increased resting during daytime among the organic group.
"For most of the response measurements in the present study there was no differences between the three diets. But in all cases, where differences were observed, there was a beneficial effect of the organically grown diet regarding the health of the rats. This indicates a positive effect of organically grown foods as compared to conventionally grown food," said the researchers.
They added that the results cannot be extrapolated to all organic and conventional cropping systems as, for example, the crops were grown only in one replication and a very low level of fertiliser was used in the organic system.
"Nevertheless, the results show the need for further interdisciplinary research in the area of human health aspects in relation to organic foods," they concluded.
The past five years have seen a boom in the organic food market with sales across Europe doubling since 1998. Figures from analysts Mintel reveal that consumers in Italy, Spain, Germany, the UK and France spent a total of €8 billion on organic food.
