Human Health Implications of Consuming Grass-fed Meat and Milk Products¶
After we fed our dairy and beef animals a high green or ensiled forage diet and took care not to mess things up cooking meat or processing milk, was this all-in-vain? Probably not, but it depends on if we believe the old nutrition science or the new one. We have had more recent research that tends to indicate that saturated fats or at least certain ones have very little to no impact on cardiovascular health. The old science is what led every-one to believe that all saturated fats clogged arteries.
Then, there is the issue of omega-3 not being changed dramatically in quantity even if the percentage change between grass-fed meat and milk and confinement-fed animals is two-fold or more. As true as that might be, it is actually the n-6:n-3 ratio that is most important. The typical America diet has ratio well above the maximum level thought to be healthful – 4.0. A diet with grass-fed full fat milk products in it would help bring the n-6:n-3 ratio down to 4.0 or less. Add some grass-finished red meat in the diet, and it would lower the overall ratio down.
CLA is thought to be healthful, but we are still waiting for a definitive study that involves human trials, not lab animals. We can raise livestock that have more CLA in their meat and milk. The trouble is that we still do not know if it is worth the trouble to produce meat and milk products from pastured livestock. In countries where meat and milk products are not shunned, but embraced, they consume enough CLA to be likely enough to reduce cancer incidence if human trials bear out what has been learned from animal trials.
The saturated fat controversy has gone on far too long with little to no true resolution. We seem to be in a 20th century time warp. It impedes dietary recommendations as long as saturated fats of any type are restricted to less than 10 percent of calories per day. Omega-3 (n-3) is stripped out of skim milk products so some of us resort to fish oil supplements and the like. Demand for dairy products continues to slip; driving more dairy farmers out of the business. Beef prices at the farm have been reasonably good, but only due to prolonged droughts that caused some beef producers to reduce their cattle numbers significantly. Meanwhile, we consume way too much n-6 in relation n-3 even with lightening up on meat and dairy. It is the n-6 that some say is the real culprit to clogged arteries, not saturated fats. Who is right? The American public needs to know now, not years from now.
Another issue with fatty acids is the origin of trans fats. From healthyforgood.heart.org, “There are two broad types of trans fats found in foods: naturally-occurring and artificial trans fats. Naturally-occurring trans fats are produced in the gut of some animals, and foods made from these animals (e.g., milk and meat products) may contain small quantities of these fats. Artificial trans fats (or trans fatty acids) are created in an industrial process that adds hydrogen to liquid vegetable oils to make them more solid. The primary dietary source for trans fats in processed food is “partially hydrogenated oils.” In November 2013, the U.S. Food and Drug Administration (FDA) made a preliminary determination that partially hydrogenated oils are no longer Generally Recognized as Safe (GRAS) in human food.” Some jurisdictions around the World outright ban them from being in food.
Reducing the milk fat content also strips out a lot of other bioactive fatty acids in milk that have a great impact on human health. We need to look at the side effects of our actions. Tunnel vision that focuses on one thing to the detriment of everything else is not good scientific work. Even worse, if the focal point was predicated on limited or flawed data or a questionable cause/effect relationship, it should be restudied exhaustively to make sure the original premise had merit in the first place. Then, be willing to admit to a mistake.
In this session, we have three presentations that speak to these issues. The first presen-tation is an overview. The second presentation takes a look at ruminant fatty acids in rela-tion to industrially hydrogenated. The third presentation focuses in on milk fatty acids and their effect on human health.
Naomi K. Fukagawa*, MD Ph.D.
David J. Baer*, Ph.D.
Jana Kraft*, Ph.D.