1- Butter is the highest source of CLA, or Conjugated Linoleic Acid, which is a short chain fatty acid that inhibits cancer of skin, colon, breast, and lungs. Multiple studies have shown significant reductions of tumors in lab rats.
2- Butter is 4% butyric acid, which is another anti-carcinogenic short chain fatty acid which has been shown to inhibit growth of mammary tumors. This is also a biological response modifier, which helps your body’s response to infection.
3- Butter does NOT make you fat. Butter is a rich source of short and medium chain fatty acids, which are not deposited to any extent in adipose tissue.
4- Butter has something called Activator X, since found to be Vitamin K2, it can be used for therapeutic treatment of illness. In a study by Weston Price in 1939 it was found that butter high in Activator X combined with a favorable selection of natural foods treats tooth decay. It has also been shown to reduce risk of prostate cancer by 35%. This factor, and others, are higher in summer when cows are grazing on grass.
5- Butter is packed with fat soluble vitamins, like A,D, and E, while it also carries the fat necessary for absorption.
Now, that being said, all foods in reasonable amounts, it is possible to eat too much healthy food, enjoy in moderation.