The Effect of Animal Protein and Vegetable Protein Diets Having the Same Fat Content on the Serum Lipid Levels of Young Women

Serum cholesterol, serum lipid phosphorus and serum fatty esters were determined for 12 young women, 6 of whom consumed a diet containing 50 gm of protein from vegetable sources, while the diet of the other 6 subjects contained 50 gm of protein from animal sources. The mixed fat content of the two diets was the same in quantity (95 gm) and origin. At the end of two weeks and 5 weeks on the dietary regimen, the serum cholesterol levels of the subjects receiving the vegetable-protein diet were significantly lower than those eating the animal-protein diet. They were also lower at the third, 4th and 6th weeks, but the differences were not significant. Serum lipid phosphorus levels of the vegetable-protein group were lower than those of the animal-protein group at the end of two weeks, but there was no difference during the remaining 4 weeks. There was no difference between the serum fatty ester levels of the two groups during the 6 weeks. There was a significant decrease in the serum cholesterol levels of both groups during the 6 weeks. Also a small decrease was observed in the serum lipid phosphorus levels of the vegetable-protein group, but no change in the serum lipid phosphorus levels of the animal-protein group nor in the serum fatty ester levels of either group during the study.