If you're looking to protect your health you might want to start buying organic products.
Organic milk and meat has been found to contain 50% more beneficial omega-3 fatty acids than non-organic produce, the Press Association reports.
Researchers also found that organic meat has slightly lower concentrations of two saturated fats which have been linked to an increased risk of heart disease in the past.
"Nutritionists do not agree on many things, but they all say we should double our intake of omega-3," study lead Professor Carlo Leifert, of Newcastle University, said.
According to the NHS, omega-3 fatty acids may help to prevent heart disease. They're also an important part of diet for women who are pregnant or breastfeeding, because they can help a baby's nervous system to develop.
The latest study, published in the British Journal of Nutrition, reviewed 196 papers on milk and 67 on meat and found clear differences between organic and conventional products.
The most notable differences were found to be the fatty acid composition and the concentrations of certain essential minerals and antioxidants.
Chris Seal, professor of food and human nutrition at Newcastle University, said: "Our study suggests that switching to organic would go some way towards improving intakes of these important nutrients."
The review found organic milk contained 40% conjugated linoleic acid, used as a weight loss supplement and by bodybuilders. It also had slightly higher concentrations of iron, Vitamin E and some carotenoids than conventional milk.
The researchers said that differences between organic and conventional milk and meat was likely due to the fact that organically reared animals eat grass, which contains the fats they require to develop, rather than concentrated cereal feeds.
"People choose organic milk and meat for three main reasons: improved animal welfare, the positive impacts of organic farming on the environment, and the perceived health benefits," Professor Leifert added.
"But much less is known about impacts on nutritional quality, hence the need for this study.
"Several of these differences stem from organic livestock production and are brought about by differences in production intensity, with outdoor-reared, grass-fed animals producing milk and meat that is consistently higher in desirable fatty acids such as the omega-3s, and lower in fatty acids that can promote heart disease and other chronic diseases."
The study also showed that conventional milk contained 74% more of the mineral iodine and slightly more selenium than organic milk.
According to the NHS, iodine helps to make the thyroid hormones which keep our metabolic rate healthy, but too much of it can lead to thyroid problems.
Professor Leifert said: "Taken together, the three studies on crops, meat and milk suggest that a switch to organic fruit, vegetables, meat and dairy products would provide significantly higher amounts of dietary antioxidants and omega-3 fatty acids."
