Silly Statements about Skim Milk

Manfred Kroger, Ph.D.
July 25, 2007

The Weston A. Price Foundation Web site contains a statement about powdered milk written by one of its officers:

A note on the production of skim milk powder: liquid milk is forced through a tiny hole at high pressure, and then blown out into the air. This causes a lot of nitrates to form and the cholesterol in the milk is oxidized. Those of you who are familiar with my work know that cholesterol is your best friend; you don’t have to worry about natural cholesterol in your food; however, you do not want to eat oxidized cholesterol. Oxidized cholesterol contributes to the buildup of plaque in the arteries, to atherosclerosis. So when you drink reduced-fat milk thinking that it will help you avoid heart disease, you are actually consuming oxidized cholesterol, which initiates the process of heart disease.

The facts are otherwise:

  • To make the powder, skim milk is concentrated by water removal under reduced pressure (by boiling the water away at about 115 degree F) and then atomized through a nozzle under high pressure into a hot chamber. The small droplets dry immediately and fall to the floor, from whch they (now in powder form) are conveyed away for packaging.
  • I know of no evidence that these processes produce nitrates.
  • Nothing in the scientific literature addresses cholesterol oxidation during skim milk powder production. However, because cholesterol is associated with fat, and because nearly all fat is removed from the skim milk, the amount of cholesterol (oxidized or not) in skim milk powder would be insignificant.
  • Some literature deals with the formation of oxidized cholesterol during prolonged storage of fatty foods (similar to an old bike rusting away with iron oxide during long storage). Whether cholesterol oxide, as found in many foods, is a health hazard has not been resolved. Eating fresh products is one way of avoiding them; but no specific food has ever been identified as important to avoid. Presumably, when cholesterol oxidizes, so do other food components, which most likely leads to an unpleasant flavor that will cause people not to eat the food. Old and oxidized pork or nuts are probably the worst offenders.
  • Plaque formation is multifactorial. Cholesterol oxide would be at or near the bottom of possible risk factors.

Waging war against any type of skim milk is just plain silly.

This article was posted on July 25, 2007.