A New Fat-Soluble Dietary Factor

By Walter C. Russell

Summary: One of the great mysteries of early nutritional research was the identity of a certain fat-soluble substance shown by Dr. Rosalind Wulzen to prevent irregular calcification of the tissues. Dr. Wulzen first observed the effects of a deficiency of this factor in experiments she was conducting on guinea pigs, whose wrists stiffened as a result of a lack of the substance. Upon feeding the animals some fresh raw cream, she found that the animals’ wrists returned to normal—the calcification having reversed—and she thus named the substance the “anti-stiffness factor,” though in many circles it became known simply as the Wulzen factor. The following excerpt from Stanford University’s Annual Review of Biochemistry for 1944 introduces readers to this “new fat-soluble factor,” the precise identity of which remains debated to this day. (Dr. Royal Lee proposed that the Wulzen factor was none other than Dr. Weston Price’s famous “Activator X.”) One fact about the Wulzen factor remains unequivocal, however: while raw cream and milk ridded Dr. Wulzen’s guinea pigs of their calcification stiffness, pasteurized cream and milk did not, as the investigator herself recorded. This fact should give anyone studying nutrition pause about what we think we know about milk, given that virtually all studies of it over the past half century been on pasteurized versions. (To learn more about the nutritional differences between raw and pasteurized milk, see “Abstracts on the Effect of Pasteurization on the Nutritional Value of Milk.”) From the Annual Review of Biochemistry, 1944. Lee Foundation for Nutritional Research reprint 127.

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A New Fat-Soluble Dietary Factor

In a group of papers published in 1935 and 1936, Wulzen and Bahrs143—145 reported their studies of the effect of certain foods in the diet of the guinea pig on the nutritive quality of certain tissues of this species for planarian worms:

When fresh grass or kale was added to a basal diet designed to be adequate except for vitamin C, guinea pig tissues from animals on this diet had satisfactory nutritional properties for the worms. On the other hand, if orange juice or tomato juice was fed in place of the green food, then the feeding of liver, heart, and kidney tissue produced severe dietary disease in planaria. The tissues became deficient for planaria after the guinea pigs had been on the diet without green food for one month, though the animals themselves had a normal appearance. If, however, the guinea pigs were allowed to remain on the diet for several months, then a deficiency developed that always proved fatal.

These studies led to the conclusion that a substance is present in fresh kale and fresh alfalfa that is essential for planarian and mammalian nutrition. Apparently, no attempt has been made to isolate the factor in green plant tissue.

Several years later, in 1941, these investigators146 reported that guinea pigs fed raw milk with an addition of skim milk powder, copper and iron salts, carotene, and orange juice grew well and showed no abnormalities at autopsy. When pasteurized whole milk was used, deficiency symptoms began to appear—wrist stiffness being the first sign.

The substitution of skim milk for whole milk intensified the deficiency, which was characterized by great emaciation and weakness before death. The animals remained in normal posture and showed little tendency toward paralysis of the limbs. At autopsy the muscles were found to be extremely atrophied, and closely packed fine lines of calcification ran parallel to the fibers. Also, calcification occurred in various other parts of the body. When cod liver oil replaced carotene in the skim milk diet, paralysis developed quickly. The feeding of raw cream cured the wrist stiffness.

The deficiency symptoms on the milk diets are not identical with those induced by a lack of green food in the diet, although the two deficiencies may have some features in common. In a continuation of the study of the factor in raw cream, van Wagtendonk and Wulzen147 reported in 1943 that vitamin E would not cure or prevent the deficiency, although the symptoms resembled those due to a lack of this vitamin, and that the “grass juice factor”148 was also ineffective. Gouley149 reported that raw cream contained methyl vinyl ketone and that this substance was the curative factor, but the presence of the ketone was not confirmed by van Wagtendonk and Wulzen. A dosage of 5 mg of the synthetic ketone each day for six days cured the wrist stiffness but was very toxic.

Using the disappearance of wrist stiffness as the criterion, van Wagtendonk and Wulzen have defined one guinea pig unit (U) as follows: “A solution of an active fraction in Wesson oil contains one unit per cc if, when 1 cc is administered daily for five consecutive days to a sick animal, it cures the affected animal in this time…” The cure refers to the disappearance of wrist stiffness.

These workers, starting with 15 gallons of raw cream whose potency was 1 U per g, containing a total of 51,000 U, obtained 3 mg of concentrate with potency of 10,000,000 U per g, a recovery of 30,000 of the original 51,000 U. The steps of the isolation procedure included saponification and extraction with ether and were of such a nature as might be expected to yield a substance with fat-soluble properties. The operations were carried out in an atmosphere of nitrogen because heating cream in the presence of oxygen destroys the factor.

The substance is reported to have a molecular weight of about 200 and to contain a carbonyl group, although on the basis of the papers available to the reviewer, the evidence for these conclusions is not clear.

Because of the rapid advances that have been made in our knowledge of the role of specific substances in mammalian nutrition, it would seem advisable to determine whether the deficiency symptoms appear when guinea pigs are fed a diet of the synthetic type in which all of the known essential nutrients have been supplied in liberal quantities and, whenever possible, as chemical entities.

Since the symptoms in the guinea pig resemble those due to a lack of tocopherol, although this factor did not cure or prevent the deficiency disease, attention should be given to the recent report by Patrick and Morgan110 that an unrecognized fat-soluble substance is present in yeast and in soybean phosphatides that is necessary for the proper utilization of vitamin E by the chick.

Whether the dietary essential reported by Wulzen and Bahrs to be present in green food and that in cream are identical is yet to be demonstrated.

—Excerpted from “The Fat-Soluble Vitamins” in Annual Review of Biochemistry, Volume XIII, 1944. References cited in this article were not included with original document.

By Walter C. Russell, New Jersey Agricultural Experiment Station, Rutgers University, New Brunswick, New Jersey. Reprinted by the Lee Foundation for Nutritional Research from the Annual Review of Biochemistry, 1944, Volume XIII, Stanford University, James Murray Luck, Editor, James H.C. Smith, Associate Editor, Carnegie Institution of Washington, Division of Plant Biology, Stanford University, California. Annual Reviews, Inc., Stanford University P.O., California. 

Reprint No. 127
Lee Foundation for Nutritional Research
Milwaukee, Wisconsin

Note: Lee Foundation for Nutritional Research is a nonprofit, public-service institution, chartered to investigate and disseminate nutritional information. The attached publication is not literature or labeling for any product, nor shall it be employed as such by anyone. In accordance with the right of freedom of the press guaranteed to the Foundation by the First Amendment of the U.S. Constitution, the attached publication is issued and distributed for informational purposes.


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