Studies show that grass-fed butter may be more nutritious. In particular, it contains a higher proportion of healthy unsaturated fatty acids (6Trusted Source, 7Trusted Source).
For example, grass-fed butter is higher in omega-3 fatty acids. These are thought to have anti-inflammatory properties and have been linked to many health benefits.
One analysis found that grass-fed butter provides about 26% more omega-3 fatty acids than regular butter, on average (7Trusted Source).
Another analysis determined that grass-fed dairy may pack up to 500% more conjugated linoleic acid (CLA) than regular dairy. Studies have linked this fatty acid to many potential health benefits (8Trusted Source).
For instance, CLA has demonstrated promising anticancer effects in animal and test-tube studies, though more research is needed (9Trusted Source, 10Trusted Source, 11Trusted Source).
In addition to boasting a healthier fat profile, grass-fed butter is believed to be much richer in vitamin K2, which plays an important role in bone and heart health (12).