Wetter, cooler summers can have a detrimental effect on the milk we drink, says a new research.
Researchers found milk collected during a particularly poor UK summer and the following winter had significantly higher saturated fat content and far less beneficial fatty acids than in a more "normal" year.
"We wanted to check if what we found on farms also applies to milk available in the shops," said Gillian Butler, who led the study.
"Surprisingly, the differences between organic and conventional milk were even more marked. Whereas on the farms the benefits of organic milk were proven in the summer but not the winter, in the supermarkets it is significantly better quality year round."
While undertaking their research into the differences between organic and conventional milk, the researchers discovered the surprising link between milk quality and our changing climate. Their results suggest that if we continue to have wetter, cooler summers then farmers may have to rethink their current dairy practices.
There was a considerable difference between the milk bought in the first sampling period (July 2006 and January 2007) and corresponding times a year later. The second set of samples, following a particularly wet summer in 2007, was higher in saturated fat and lower in beneficial fatty acids.
They concluded that organic brands of milk available in supermarkets are higher in beneficial fatty acids such as CLA and omega-3 fatty acids in summer (as in their previous research) and winter (where previous research showed that the difference in the winter was not as noticeable).
The study has been published in Journal of Dairy Science.