Denke M A
Center for Human Nutrition, University of Texas Southwestern Medical Center at Dallas 75235-9052.
Am J Clin Nutr. 1994 Dec;60(6 Suppl):1044S-1049S. doi: 10.1093/ajcn/60.6.1044S.
The effects of stearic acid on metabolism must be evaluated for stearic acid as an isolated dietary constituent and for stearic acid as a component of a natural fat. Beef products are the most common source of dietary stearic acid in the United States. Two components of beef products, beef protein and beef fat, can potentially impart cholesterol-raising properties. Protein has minimal effects on cholesterol concentrations in humans, but studies suggest that beef fat raises serum cholesterol concentrations. Because beef fat is 19% stearic acid, the cholesterol-raising potential of beef is not as great as predicted by its total saturated fatty acid content. However, beef tallow is hypercholesterolemic compared with fats containing less cholesterol-raising saturated fatty acid. Therefore, curtailment of beef tallow in a cholesterol-lowering diet seems appropriate. Data suggest that lean beef is no more hypercholesterolemic than chicken or fish and, therefore, lean beef need not be eliminated from cholesterol-lowering diets.
必须分别评估硬脂酸作为一种孤立的膳食成分以及作为天然脂肪的组成部分时对新陈代谢的影响。牛肉制品是美国膳食中硬脂酸最常见的来源。牛肉制品的两个组成部分，牛肉蛋白和牛肉脂肪，都可能具有升高胆固醇的特性。蛋白质对人体胆固醇浓度的影响极小，但研究表明牛肉脂肪会提高血清胆固醇浓度。由于牛肉脂肪中19%是硬脂酸，牛肉升高胆固醇的潜力并不如其总饱和脂肪酸含量所预测的那么大。然而，与含较少升高胆固醇饱和脂肪酸的脂肪相比，牛油会导致血液胆固醇过高。因此，在降低胆固醇的饮食中减少牛油的摄入似乎是合适的。数据表明，瘦牛肉导致血液胆固醇过高的程度并不比鸡肉或鱼肉更高，因此，在降低胆固醇的饮食中无需剔除瘦牛肉。
