Are you able to find the link for the study/article? I am having difficulty locating that information on the Which.co.uk site.
There are some studies from around 2007, 2009, 2014, 2017 (https://www.tandfonline.com/doi/full/10.1080/16546628.2017.1287333) and 2019 (Foods | Free Full-Text | A Comprehensive Analysis of Organic Food: Evaluating Nutritional Value and Impact on Human Health) and some are finding no nutritional difference but the last 3 seem to indicate that the organically grown may have some better outcomes that previously thought. The 2014 meta study (Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses - PubMed) seems to have some criticism about what studies were analysed, but was a peer reviewed article and is still referenced throughout other literature and studies…
From the EU Parliament is this about organic milk and dairy products Vs non-organically farmed
“7.5. Conclusions
For milk and dairy products, it has been conclusively demonstrated that organic products have a
higher content of omega-3 PUFAs, across countries and seasons, due to a higher content of grass and
roughage in the feed of organic cows. In a direct comparison, organic dairy products therefore have a
more beneficial fatty acid composition. The same is apparently true for meat as well, although fewer
studies have investigated this and therefore the evidence base is weaker. Dairy products make only a
minor contribution to the omega-3 intake in humans. On average, replacing conventional with organic
dairy products while keeping the diet constant will increase the intake of omega-3 PUFA by
approximately 4 %. Replacing conventional meat products with organic meat products may increase
the omega-3 intake by an additional 6 %. Policies aimed at increasing the omega-3 intake of the
population are likely to be far more efficient if they are directed at increasing the intake of omega-3-
rich plant oils (e.g. rapeseed/canola and linseed) and fatty fish, with the desirable side effect of
simultaneously reducing the intake of saturated fatty acids”
