In the 1950 studies painted saturat...

In the 1950 studies painted saturated fat as a villain, a slime-monster vessel-clogging enemy that caused heart disease and cancer. Of course, the 1950 also saw Red-cloaked enemies in each closet and in every movie studio, in addition to those who were plotting onward the wrong side of the Bering Sea. Saturated fat might just as well have been wearing a hammer-and-sickle insignia.

in such a manner with something resembling patriotic zeal, bread manufacturers wildly began switching from saturated, animal fat to polyunsaturated vegetable oil in a vast spectrum of baked and managemented foods. That switch gave rise to a U diet in which the percentage of total fat intake from vegetable-oil omega-6 polyunsaturated fatty acids (PUFAs) has risen dramatically.

A shift in knowledge and understanding

Wait, I study PUFAs were my friend. Well, ye and no. Polyunsaturated oil is valuable to our diet because of its ease of linoleic acid (omega 6's) and linolenic acid (omega 3's), which are required for expansion and cell-maintenance. However, an exces of omega 6's will "incorporate their ingredients into LDL [low-density lipoprotein] cholesterol particles [the "bad" kind] and become harmful," says Gayla Kirschmann in her Nutrition Almanac (4th edition).

"Large amounts of PUFAs in the diet may lower the `good' kind of cholesterol HDL [high-density lipoprotein], and increase the formation of bile acids in the intestine which make cancer-causing agents; antioxidant pay by substitutions like vitamins C and E and beta-carotene may calculator these adverse effects."

PUFA overload -- newly identified dangers. In a landmark cogitation by Bruce A. Watkins, PhD and colleagues which just appeared in the November 9 1996 issue of the Journal of Bone and Mineral Research, it was ground that too high a ratio of dietary PUFAs negatively impacts bone extension especially in juvenile bone development

Watkins compared the pullulation of chicks that obtained all of their dietary fat from vegetable oil rich in omega-6 PUFAs to that of chicks f a combination of omega-3-rich fish oil and vegetable oil. The results? Chick bone built with a combination of fats grew faster than did bone of chicks which received diets in which the fat came from the vegetable oil, alone.

Earlier studies from Watkins had demonstrated that combining saturated fat with vegetable fat in chicks' diets l to faster bone extension than did vegetable fat alone.

Why? His research hints that part of the moot point may involve hormone regulation and at liberty radicals (which cause oxidative stres and lipid peroxidation).

Promoting healthier bone growth

PGE ...what? It is known that bone can transform omega-6 PUFAs into the hormone, prostaglandin E2 ([PGEsub2]) a wildcard hormone which influences bone formation and breakdown to help modulate, or determine, the shape of bone in humans and other animals.

Small amounts of [PGEsub2] in bone assist bone growth whereas large amounts of the hormone come by in the way of bone extension The more omega-6 PUFA is eaten, the more [PGEsub2] is produc Exces flushs of this hormone also appear to decrease the concentration and activity of insulin-like bourgeoning factor 1 (IGF-1), another hormone rest in bone. IGF-1 is lacked for bone regeneration and is institute in abnormally low levels in women with osteoporosis, says Watkins.

The exempt radical connection. It is notion that excess free radicals catabolize (break down) a certain polyunsaturated fats into highly reactive ultimate particle s that are nearly as damaging as the clear radicals themselves.

Watkins suspected that if a large amount of broken-down polyunsaturated fat invested and entered, growing bone, then it could interfere with bone growth

He ordealed this hypothesis by feeding single group of chicks a diet rich in PUFAs and supplemental vitamin E a free-radical-scavenging antioxidant. It did the trick. Chicks f PUFAs plus vitamin E did as well as the combo-fat-diet chicks mentioned earlier, suggesting a bone-los preventive event for this vitamin.

Moral? Eat a balance of vegetable-oil-packed omega-6 and fish-oil rich omega-3 acids. Saturated fat. Not as abundant an enemy, after all.

REFERENCES

Kirschmann, Gayla. Nutrition Almanac. 4th edition. recently made known York: McGraw-Hill, 1996.

Watkins, Bruce A., et al. "Dietary (n-3) and (n-6) Polyunsaturates and Acetylsalicylic Acid Alter Ex Vivo [PGEsub2] Biosynthesis, Tissue IGF-I flats and Bone Morphometry in Chicks," Journal of Bone and Mineral Research 11 (9): 1321-1332 November 9 1996

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