It's long been a contentious debate: Is organic food really any better for you than non-organic food? Well, now those who are proponents of organic eating may have some proof—by way of the largest study of its kind to date.

The researchers, led by experts from Newcastle University, reviewed 196 papers on milk and 67 papers on meat and discovered several trends between them—namely, that organic and conventional milk and meat have different fatty acid compositions and essential mineral levels.

In fact, the study, which is published in British Journal of Nutrition, found that organic whole milk and meat had 39 milligrams of omega-3 fatty acids, whereas conventional milk averaged 25 milligrams—meaning that organic milk has more than 50% more omega-3 fatty acids than conventional products.

The meat was found to have around 50% more omega-3s as well. Since many Americans and Europeans don't ingest enough of these essential nutrients on a weekly basis, this means that, according to the study, a switch of conventional milk to organic milk would allow you to consume more of these nutrients without changing your caloric intake—which would have many benefits.

"Omega-3s are linked to reductions in cardiovascular disease, improved neurological development and function, and better immune function," explained Chris Seal, Professor of Food and Human Nutrition at Newcastle University, in a statement.

"Western European diets are recognised as being too low in these fatty acids and the European Food Safety Authority (EFSA) recommends we should double our intake. But getting enough in our diet is difficult. Our study suggests that switching to organic would go some way towards improving intakes of these important nutrients."

According to the study, they also discovered that organic milk had significantly higher levels of fat soluble vitamins, like vitamin E and carotenoids—40% more. Organic milk also had a more desirable fat profile, with a better ratio of omega 3s to omega 6s (the best ratio for humans is to ingest 1:1 overall, which most people fail to achieve) and lower amounts of myristic and palmitic acid—fats which are tied to heart disease.

So why are they different?

It appears that the differences between organic and conventional milk and meat stems from a simple source: What the animals themselves ate.